From traditional desktop to novel optical designs in small form factors. Towards portable low-cost fundus imaging designs with computational imaging techniques for image quality improvement.

1. Petteri Teikari, PhD
Singapore Eye Research Institute (SERI)
Visual Neurosciences group
http://petteri-teikari.com/
Version “Wed 10 October 2018“
Optical designs
for fundus imaging
From traditional desktop
to novel optical design in small
form factors

2. “Traditional”
Fundus
Imaging
Optical
Designs

3. Intro to
Fundus Optics
Design
2009
Funduscamerasystems:
acomparativeanalysis
https://doi.org/10.1364/AO.48.000221
EdwardDeHoogandJamesSchwiegerling
Applied OpticsVol. 48, Issue2, pp.221-228 (2009)
Retinal photography requires the use of a
complex optical system, called a fundus
camera, capable of illuminating and imaging
the retina simultaneously. The patent literature
shows two design forms but does not
provide the specifics necessary for a thorough
analysisofthedesignstobeperformed.
We have constructed our own designs based
on the patent literature in optical design
software and compared them for illumination
efficiency, image quality, ability to
accommodate for patient refractive error, and
manufacturing tolerances, a comparison
lackingintheexistingliterature.
external
illumination
design
internal
illumination
design
Tolerance analysis must always be considered when
determining which system is able to perform a specific task
better. Systems with high performance metrics but extremely
tight or impossible tolerances are likely to be passed over for
productionor redesignedtomakemanufacturingeasier
Kidger, Intermediate Optical Design (SPIE, 2004)
Shannon, The Art and Science of Optical Design (1997)CVI Melles Griot, “
Optical fabrication tolerances”
Rochester Precision Optics, “Traditional optics capability”.
Resultsof 100 MonteCarlo Trialsof FundusCameraSystems
“Retinal imaging presents a unique difficulty considering that the retina must be illuminated and imaged
simultaneously, a process which forcesillumination and imaging systems to share a common optical path. Because
the retina is a minimally reflective surface, the power of the back reflections from the shared optics of the
illuminationandimagingpathsisgreater thanthepowerreflectedbytheretina.“

4. Traditional
fundus camera
design
Opticaldiagramofatraditionaldigitalfunduscamerawithitsthreebasicmodulus–objective,illuminationandcamera.
DeMatosetal.(2015),http://doi.org/10.1117/12.2190515
DeOliveiraetal.(2016),http://doi.org/10.1117/12.2236973

5. Fundus
Cameras
Commercial
Landscape#1
VishwanathManik Rathod
http://raiith.iith.ac.in/4141/1/Thesis_Mtech_EE_4141.pdf

6. Fundus
Cameras
Commercial
Landscape#2Vishwanath Manik Rathod
http://raiith.iith.ac.in/4141/1/Thesis_Mtech_EE_4141.pdf
NextSight Nexy Tutorial-funduscameraSIROftalmica
https://youtu.be/JxmFyhFRN3g
Nexy RoboticRetinalImaging SystemReceivesFDA ...- EyewireNews
GlobalFundusCamerasMarkettobeworth
USD620Million By2024 -ZionMarketResearch
https://globenewswire.com/news-release/2018/08/
19/1553691/0/en/Global-Fundus-Cameras-Market-
to-be-worth-USD-620-Million-By-2024-Zion-Marke
t-Research.html
Fundus Cameras Market: by Product Type (Mydriatic Fundus Cameras
[Tabletop and Handheld], Non-mydriatic Fundus Cameras [Tabletop and
Handheld], Hybrid Fundus Cameras, and ROP Fundus Cameras) and by
End User (Hospitals, Ophthalmology Clinics, and Others): Global Industry
Perspective,ComprehensiveAnalysisandForecast,2018- 2024

7. Pen-like fundus
camera design
December2009
US8836778B2Portablefunduscamera
https://patents.google.com/patent/US8836778B2/en
Filipp V. IGNATOVICH, David M. Kleinman, Christopher T.
Cotton, Todd Blalock LUMETRICSInc
Legalese description: “Camera for imaging the fundus of an eye, the camera comprising optics aligned along an
imaging axis intersecting a point on the fundus and configured to focus light reflected back from the fundus onto an image
receptor, wherein the optics are capable of varying a field of view of the camera along a path circumferentially around the
point on the fundus, whereby the image receptor acquires images of portions of the fundus located at different peripheral
locationsaroundthepointofthefundus”

8. Spectral
Characterizatio
n of typical
fundus camera
September2010
Spectralcharacterizationofan
ophthalmicfunduscamera
https://doi.org/10.1117/12.844855
ClaytonT.Miller;CarlJ.Bassi;DaleBrodsky;
TimothyHolmes
This work describes the characterization of
one system, the Topcon TRC-50F, necessary
for converting this camera from film
photography to spectral imaging with a
CCD. Thisconversion consistsofreplacing the
camera's original xenon flash tube with a
monochromatic light source and the film back
with a CCD. A critical preliminary step of this
modification is determining the spectral
throughput of the system, from source to
sensor, and ensuring there are sufficient
photonsatthesensor for imaging.

9. Dynamic
Artifacts
Cardiacgating
forfundus
2003
TimeCourseofFundusReflectionChanges
AccordingtotheCardiacCycle
https://iovs.arvojournals.org/article.aspx?articleid=2413124
R.P. Tornow;O.Kopp; B.Schultheiss
To compare the time course of fundus reflection from
video sequence (25 frames/sec) at different retinal
locationswithcardiacparameters.
The pulsatile reflection component ΔR(t) R(t)
changes corresponding to the cardiac cycle. ΔR(t) R(t)
rises suddenly during systole, reaches its maximum
after about 32 % of the pulse duration time (RR-
interval) and decreases towards the end of the
diastole. The pulse shape of ΔR(t) R(t) shows a high
correspondence to the cardial impedance signal
while it is different from the pulse shapes of the
peripheralimpedancesignals.
The reflection of the ocular fundus depends
on the cardiac cycle. The simultaneous
assessment of ΔR(t) R(t) and the impedance signals
allows to correlate parameters of ocular
microcirculation with cardiac parameters and
to distinguish physiologically induced
reflection changes from artifacts. More than
this, the pulsatile reflection amplitude has to be taken
into consideration for quantitative imaging like retinal
densitometry.
November 2016
Retinalvenouspulsation:Expandingour
understandinganduseof thisenigmatic
phenomenon
https://doi.org/10.1016/j.preteyeres.2016.06.003
WilliamH.Morgan,Martin L.Hazelton,Dao-Yi Yu
Recently, improved ophthalmodynamometry and video
recording techniques have allowed us to explore the
fundamentals of retinal vein pulsation. This demonstrates that
retinal venous collapse is in phase with both IOP and CSFP
diastole, indicating the dependence upon CSFP pulse. We
describe in some detail the mathematical and physical models of
Starling resistors and how their results can be applied to
understand the physiology of retinal vein pulsation.
October2017 AutomaticDetectionofSpontaneousVenousPulsationsUsing
RetinalImageSequences https://doi.org/10.1007/978-3-319-68195-5_90
Michal Hracho, Radim Kolar,Jan Odstrcilik, IvanaLiberdova, RalfP.Tornow
Evaluation ofmagnitude ofspontaneous venous pulsationhas been proven to
correlatewith occurrenceofglaucoma. Based on this relation a methodis
proposed that might help to detect glaucomavia detection ofspontaneous venous
pulsation.

10. Modify
Existingfundus
camera for custom
applications
2010
High-resolutionhyperspectralimagingoftheretinawithamodifiedfunduscamera
NourritV,DennissJ,MuqitMM,SchiesslI,FenertyC,StangaPE,HensonDB.
http://doi.org/10.1016/j.jfo.2010.10.010
Thispaper givesinformation on
howtoconvert astandard
funduscameraintoa
hyperspecral camera with off
the shelf elements (CCD
camera, liquid crystal filter,
optical fibre and slide lamp
projector).
Technically, itsmain limitation is
the low transmissionof the filter
(20% maxfor unpolarized light
below 650 nm), which limits
imagingbelow460 nm.

11. Remidio
Smartphone-based
commercialized
fundus camera
https://doi.org/10.1038/s41433-018-0064-9
http://remidio.com/
June2011
US9398851B2Retinalimagingdevice
https://patents.google.com/patent/US9398851B2/en
https://patents.google.com/patent/WO2018047198A3/en
SivaramanAnand,KummayaPramod,
NagarajanShanmuganathan
remidioinnovativesolutionspvtltd

12. MobileVision
APortable,Scalable
RetinalImagingSystem
TIEngibousCompetition Report
Rice University
2012
mobileVisionsystem
http://www.ti.com/corp/docs/university/docs/Rice_University_mobileVision%20Final%20Report.pdf

13. Remidio
Smartphone-based
commercialized
fundus camera
https://doi.org/10.1038/s41433-018-0064-9
http://remidio.com/
June2011
US9398851B2Retinalimagingdevice
https://patents.google.com/patent/US9398851B2/en
https://patents.google.com/patent/WO2018047198A3/en
SivaramanAnand,KummayaPramod,
NagarajanShanmuganathan
remidioinnovativesolutionspvtltd

14. Fundus Self-
Imaging “Eye
Selfie” from MIT
February2012
US9295388B2Methodsandapparatus
forretinalimaging
https://patents.google.com/patent/US9295388B2/en
MatthewEverettLawson,RameshRaskar
MassachusettsInstituteofTechnology
This invention comprises apparatus for retinal self-
imaging. Visual stimuli help the user self-align his eye with a
camera. Bi-ocular coupling induces the test eye to rotate into
different positions. As the test eye rotates, a video is captured
of different areas of the retina. Computational
photography methods process this video into a mosaiced
image of a large area of the retina. An LED is pressed
against the skin near the eye, to provide indirect,
diffuse illumination of the retina. The camerahasawide
field of view, and can image part of the retina even when the
eye is off-axis (when the eye's pupillary axis and camera's
optical axis are not aligned). Alternately, the retina is
illuminated directly through the pupil, and different parts of
a large lens are used to image different parts of the retina.
Alternately,aplenopticcameraisusedfor retinalimaging.
Computational photography techniques are
used to process the multiple images and to
produce a mosaiced image. These techniques
include (i) “Lucky” imaging, in which high-
pass filtering is used to identify images that
have the highest quality, and to discard poorer
qualityimages

15. Fundus
Eye-Selfie
http://web.media.mit.edu/~tswedish/projects/eyeSelfie.html
T. Swedish, K. Roesch, I.K. Lee, K. Rastogi, S. Bernstein, R. Raskar. eyeSelfie:SelfDirected
EyeAlignment usingReciprocalEyeBoxImaging. Proc. ofSIGGRAPH2015 (ACM
Transactions on Graphics 34, 4), 2015.
Self-aligned, mobile, non-mydriatic Fundus
Photography. The user is presented with an
alignment dependent fixation cue on a ray-based
display.Oncecorrectlyaligned,aself-acquiredretinal
image is captured. This retinal image can be used for
health, security or HMD calibration. Ilustration:
LauraPiraino
https://youtu.be/HuXgrbwOjvM
https://www.economist.com/science-and-technology/2015/0
6/13/retina-selfie
Expert-freeeyealignmentandmachinelearningfor
predictivehealthTristan BreadenSwedish
https://dspace.mit.edu/handle/1721.1/112543
Iwill present a system that includes a novel methodfor eyeself-alignmentand automaticimage
analysis and evaluate its effectiveness when applied to a case study of a diabetic retinopathy
screening program. This work is inspired by advances in machine learning that makes
accessible interactions previously confined to specialized environments and trained users. I will
also suggestsomenewdirectionsfor futurework based onthisexpert-freeparadigm.

16. Fundus
Self-
Alignment
http://web.media.mit.edu/
~tswedish/projects/eyeS
elfie.html
“Thesubject
alignshis/her
ownfor
optimalimage”

17. Check the
patent trail
Cited By(14)
US20160302665A1 *2015-04-172016-10-20MassachusettsInstituteOfTechnology MethodsandApparatus
forVisualCuesforEyeAlignment
US20170000454A1 *2015-03-162017-01-05MagicLeap,Inc.Methodsandsystemsfordiagnosingeyes
usingultrasound
WO2009081498A1 *2007-12-262009-07-02ShimadzuCorporation Organismimagecapturingdevice
EP2583619A1 *2011-10-222013-04-24SensoMotoricInstrumentsGmbHApparatusformonitoringoneor
moresurgicalparametersoftheeye
US20150021228A12012-02-022015-01-22VisunexMedicalSystemsCo.,Ltd.Eyeimagingapparatusand
systems
US9655517B22012-02-022017-05-23VisunexMedicalSystemsCo.Ltd.Portableeyeimagingapparatus
US9351639B22012-03-172016-05-31VisunexMedicalSystemsCo.Ltd. Eyeimagingapparatuswithawide
fieldof viewandrelatedmethods
US9237847B22014-02-112016-01-19WelchAllyn,Inc.Ophthalmoscopedevice
US9211064B22014-02-112015-12-15WelchAllyn,Inc.Fundusimagingsystem
US9986908B22014-06-232018-06-05VisunexMedicalSystemsCo.Ltd. Mechanicalfeaturesof aneye
imagingapparatus
US9675246B22014-09-152017-06-13WelchAllyn,Inc.Borescopicopticalsystemformedicaldiagnostic
instrumentsandmedicaldiagnosticinstrumentshavinginterlockingassemblyfeatures
EP3026884A1 *2014-11-272016-06-01ThomsonLicensing Plenopticcameracomprisingalightemitting
device
US9848773B22015-01-262017-12-26VisunexMedicalSystemsCo.Ltd.Disposablecapforaneyeimaging
apparatusandrelatedmethods
US20160320837A1 *2015-05-012016-11-03MassachusettsInstituteOfTechnology MethodsandApparatusfor
RetinalRetroreflectionImaging

18. Design for
minimizing
straylight
e.g.usepolarizedlight
source
November 2014
Design,simulationand experimental
analysisofananti-stray-light
illuminationsystemof funduscamera
https://doi.org/10.1117/12.2073619
ChenMa;DewenCheng; ChenXu;Yongtian
Wang
A fiber-coupled, ring-shaped light source that forms an
annular beam is used to make full use of light energy. The
parameters of the light source, namely its divergence angle
and size of the exit surface of the fiber rod coupler, are
determined via simulation in LightTools. Simulation results
show that the illumination uniformity of fundus can reach to
90% when a 3~6mm annular spot on the cornea is
illuminated. It is also shown that a smaller divergence
angle (i.e., 30°) benefits both the uniformity irradiance of the
fundus image on focus plane (i.e., CCD) and the sharpness
of the image profile. To weaken the stray light, a
polarized light source is used, and an analyzer plate
whose light vector is perpendicular to the source is placed
after the beam splitter in the imaging system. Simulation
shows the average relative irradiance of stray light after stray
lightelimination drops to1%.

19. PEEK Retina
Smartphone-based
fundusimaging

20. Panretinal 2.2
3DPrintedoptics
holders
2014
3DPrintedSmartphoneIndirectLens
AdapterforRapid,HighQualityRetinal
Imaging
http://dx.doi.org/10.7309/jmtm.3.1.3
DavidMyung,AlexandreJais,Lingmin He,MarkS.
Blumenkranz,RobertT.Chang
Byers EyeInstituteatStanford, StanfordUniversitySchool
ofMedicine

21. 3D Ophthalmoscope
Design
2015
Studyofopticaldesignofthree-
dimensionaldigitalophthalmoscopes
https://doi.org/10.1364/AO.54.00E224
Yi-Chin Fang,Chih-TaYen,andChin-Hsien Chu
LightToolsdiagram
A 3D optical-zoom sensory
system of the human eye with infrared
and visible light is proposed (Code V,
LightTools) to help the doctor diagnose
human eye diseases. The proposed
lens design for 3D digital
ophthalmoscopes provides a good
means of simultaneously
accessing infrared and visible
light band information to help doctors
performdiagnostics.
The diffraction limit lines in MTF plots
are almost >0.7 at spatial frequencies
up to 40 cycles/mm under all zoom
conditions in the IR region. Accordingto
the experiment results, the proposed
3D digital ophthalmoscope is suitable
forfutureophthalmoscopedesign.

22. D-Eye
3DPrintedoptics
holders
2015
ANovelDevicetoExploitthe
SmartphoneCameraforFundus
Photography
http://dx.doi.org/10.1155/2015/823139
AndreaRusso,FrancescoMorescalchi,CiroCostagliola,
LuisaDelcassi,andFrancescoSemeraro
Exploded view of the D-Eye module (angles and
distances between components are approximated).
Retinal images are acquired using coaxial illumination
and imaging paths thanks to a beam splitter (C). The
blue arrow depicts the path of the light; red arrow
depicts the path of fundus imaging. Device
components are glass platelet (A) with imprinted
negative lens (A′), photo-absorbing wall (B), beam
splitter (C), mirror (D), plastic case (E), diaphragm (F),
polarized filters (G, H), flash and camera glass (J, I),
andmagnetic external ring (K).

23. Tunable Liquid
Lens
withtranspupillary
illuminationtosimplify
theopticaldesign
2015
AccessibleDigitalOphthalmoscopy
BasedonLiquid-LensTechnology
https://doi.org/10.1007/978-3-319-24571-3_68
Christos Bergeles, Pierre Berthet-Rayne, Philip McCormac, Luis C. Garcia-
Peraza-Herrera, Kosy Onyenso, FanCao, KhushiVyas, MelissaBerthelot,
Guang-ZhongYang
Thispaper demonstratesa
newdesignintegratingmodern
componentsfor
ophthalmoscopy.Simulations
showthattheopticalelements
canbereducedtojusttwo
lenses:anaspheric
ophthalmoscopiclensanda
commodityliquid-lens,
leadingtoacompact
prototype.
Circularlypolarised
transpupilaryillumination,
withlimitedusesofarfor
ophthalmoscopy,suppresses
reflections,while
autofocusingpreserves
imagesharpness.Experiments
withahuman-eyemodeland
cadaver porcineeyes
demonstrateourprototype’s
clinicalvalueanditspotential
for accessibleimagingwhen
costisalimitingfactor.

24. Simplifying
Optical
Design
”substitute the complex
illumination systembya ring of
LEDsmounted coaxiallytothe
imaging optical system,
positioningitinthe place of the
holed mirror of the traditional
optical design.”
September2016
Evaluationofretinalilluminationin
coaxialfunduscamera
https://doi.org/10.1117/12.2236973
AndréO.deOliveira;LucianadeMatos;Jarbas
C.CastroNeto
Weevaluatedtheimpactofthissubstitution
regardingtoimagequality (measured
throughthemodulationtransfer function)and
illuminationuniformityproducedbythissystem
ontheretina.
Theresultsshowedthereisnochangeinimage
qualityandnoproblemwasdetected
concerninguniformitycomparedtothe
traditionalequipment.Consequently,we
avoidedoff-axiscomponents,easingthe
alignmentoftheequipment without
reducingbothimagequalityandillumination
uniformity.
Photograph (left) and optical drawing(center) ofthe OEMI-7OcularImaging Eye Model (Ocular
Instruments Inc.). Picture of the OEMI-7 Ocular Imaging Eye Model (right) obtained using the
innovative equipment. Noobscuration isobserved and the image isfree ofreflex.

25. Optimizing
Zemax tools for
efficient
modelling of
fundus cameras
November 2016
Minimisingbackreflectionsfromthecommonpath
objectiveinafunduscamera
https://doi.org/10.1117/12.2256633
A.SwatSolarisOpticsS.A
Eliminating back reflections is critical in the design of a
fundus camerawith internal illuminating system.Asthere isvery
little light reflected from the retina, even excellent antireflective
coatings are not sufficient suppression of ghost reflections,
therefore the number of surfaces in the common optics in
illuminatingandimagingpathsshallbe minimised.
Typically a single aspheric objective is used. In the paper an
alternative approach, an objective with all spherical
surfaces, is presented. As more surfaces are required, more
sophisticated method is needed to get rid of back reflections.
Typically back reflections analysis, comprise treating
subsequent objective surfaces as mirrors, and reflections from
the objective surfaces are traced back through the imaging
path.
There are also available standard ghost control merit
function operands in the sequential ray-trace, for example in
Zemax system, but these don’t allow back ray-trace in an
alternative optical path, illumination vs. imaging. What is
proposed in the paper, is a complete method to incorporate
ghostreflectedenergyintothe raytracing systemmeritfunction
for sequential mode which is more efficient in optimisation
process. Although developed for the purpose of specific case
of fundus camera, the method might be utilised in a wider
rangeofapplicationswhereghostcontroliscritical.
Commonlyusedamongstopticalspecialists,is
Zemaxsoftware, it doesallowto callamacro script
fromthesystemmeritfunction bytheZPLMoperand.
Thereforetheoptimisation systemcomprisethe
following:
●
Theimaging system builtin Zemax
●
A typicalmeritfunction constructedtoallowforthe
imagingsystemoptimisation
●
An additionallinein themeritfunctionto calla
macro,operandZPLM
●
ThemacrocalledbytheZPLMoperandshallopen
anewfile,wherethesecondsystemdefined,
includingasmanyconfigurationsasthenumberof
surfacesin thecommon pathsuspected to
generateparasiteback reflections. Themacro
evaluatesdetectorflux,foreachconfiguration and
itup,macroisclosedandtotalfluxvaluereturned
totheimagingsystem meritfunction.Theretuned
fluxbecomesoneofthemeritfunction
componentsbeingminimisedamongother
imagingsystemproperties,theweightis
individuallyadjustedbythedesignertobalance
systemproperties.

26. Startups
focusing on the
software stack
Nov.2016
Phelcom[UniversityofSãoPaulo(USP)],SmartRetinalCamera(SRC),aretinalscannercontrolled
byanattachedsmartphone
http://revistapesquisa.fapesp.br/en/2017/05/17/eye-on-the-smartphone/
The SRC is designed to perform three kinds of fundus exams: color, red-free, and fluorescein
angiography (FA). Paulo Schor, professor in the Department of Ophthalmology, of the Federal University of São
Paulo (Unifesp), devices that rely on smartphones to perform eye exams do not belong to the future but to the present.
“They’reaccessible–thatis,easytooperateandcheap,”

27. Miniaturized
nonmydriatic
fundus camera
design
March2017
Opticaldesignofportablenonmydriatic
funduscamera
https://doi.org/10.1117/12.2268699
WeilinChen;JunChang; FengxianLv;YifanHe;
XinLiu;DajiangWang
The ocular fundus is not luminous itself, and the
reflectivity of retina to visible light is about
0.1% to 10%. If the light blocking effect of pupil
is considered, the reflectivity of the fundus is
about 0.1% to 1%. The active illumination
is therefore needed for the total low reflectivity.
The fundus camera uses two kinds of LED as
light sources, one is 590 nm LED and the
other is 808 nm LED. The pulsed 590nm
LED is used to illuminate the capillary vessel in
the ocular fundus and take pictures for the high
contrastofthefundusimages.
Schematicofannularillumination
To evaluate the performance of the lighting system, the
optimization results from Zemax were imported into
Lighttools, and the human eye model was also added
to perform a non-sequential ray tracing. The illumination
distributioninthefundusisshown
SonyICX282AQCCD

28. Smartphone
Fundus imaging
withdesignchoices
laidout
2017
OpticalDesignofaRetinalImageAcquisitionDeviceforMobile
DiabeticRetinopathyAssessment
https://doi.org/10.1007/978-3-319-24571-3_68
David Simões de Melo, Bachelor Degree in EngineeringSciences, NOVA UniversityofLisbon

29. Smartphone
Fundus imaging
withdesignchoices
laidout
2017
APortable,Inexpensive,NonmydriaticFundusCamera
BasedontheRaspberryPi®Computer
https://doi.org/10.1155/2017/4526243
BaileyY.Shen andShizuoMukai
DepartmentofOphthalmology, Illinois Eye and EarInfirmary, University ofIllinois at Chicago;
Retina Service, Massachusetts Eye and EarInfirmary, Harvard Medical School
We built a point-and-shoot prototype camera using a Raspberry Pi
computer, an infrared-sensitive camera board, a dual infrared and
white light light-emitting diode, a battery, a 5-inch touchscreen liquid
crystal display, and a disposable 20-diopter condensing lens. Our
prototype camera was based on indirect ophthalmoscopy with both
infrared and white lights. Results. The prototype camera measured and
weighed 386 grams. The total cost of the components, including the
disposablelens, was $185.20.
Our prototype, or a camera based on our
prototype, may have myriad uses for health
professionals. For example, it may be useful
for ophthalmologists seeing inpatient consults,
as moving inpatients to a stationary fundus
camera can be impractical, and many
neurosurgery inpatients in the intensive care
unit are not allowed to be pharmacologically
dilated.
The comfort of nonmydriatic imaging may
make the camera useful for pediatric
ophthalmologists, although alignment might be
difficult. Finally, the low cost and small size of our
camera may make the camera a valuable tool
for ophthalmologistspracticing globalmedicine.
With added features such as a large memory
card and a strong wireless card or cell phone
antenna, the device could help providers
practicetelemedicine.

30. Open-source
optics design
blocks
acceleratingbasic
design
2018
μCube: A Framework for 3D Printable OptomechanicsCube:AFrameworkfor3DPrintableOptomechanics
http://doi.org/10.5334/joh.8 |https://mdelmans.github.io/uCube
MihailsDelmans, JimHaselofff(2018)UniversityofCambridge
JournalofOpen Hardware.2(1),p.2
For attaching a commercial photo camera lens, a µTMountFace is used, which features a T-Mount adapter
ring, obtained from a commercial T-Mount adapter. In the M12 CCTV camera lens version, both the lens and
theRaspberryPiCameraareheldtogether byasinglepart.CADdesigninOpenSCAD.

31. Modeling the
pupil/iris as the
imaging
aperture
May18,2018
Theentrancepupilofthehumaneye
https://doi.org/10.1101/325548
GeoffreyKarlAguirre
The precise appearance of the entrance pupil
is the consequence of the anatomical and
optical properties of the eye, and the relative
positions of the eye and the observer. This paper
presents a ray-traced (Matlab), exact model
eye that providesthe parametersofthe entrance
pupil ellipse for an observer at an arbitrary
location and for an eye that has undergone
biologicallyaccuraterotation
Calculation of the virtual image location of a pupil
boundary point This 2D schematic shows the cornea and
a 2 mm radius pupil aperture of the model eye. A camera is
positioned at a 45 viewing angle relative to the optical◦ viewing angle relative to the optical
axis of the eye. The optical system is composed of the
aqueoushumor,the back andfrontsurfacesofthecornea,
and the air. We consider the set of raysthat might originate
from the edge of the pupil. Each of these rays depart from
thepupilapertureatsomeanglewithrespecttotheoptical
axisoftheeye.Wecantracetheseraysthroughtheoptical
system

32. “Wide-Field”
Fundus
Imaging
Optical
Designs

33. Smartphone -
based wide-
field fundus
imaging
July2018
Asmartphone-basedtoolforrapid,
portable,andautomatedwide-fieldretinal
imaging
https://doi.org/10.1101/364265
TysonKim, Frank Myers,ClayReber, PJLoury,Panagiota Loumou, Doug Webster, ChrisEchanique,
Patrick Li, JoseDavila,Robi Maamari,Neil Switz,JeremyKeenan, MariaWoodward, YannisPaulus, Todd
Margolis,Daniel Fletcher
Department of Ophthalmology and Visual Sciences, University of Michigan School of Medicine; Department of
Bioengineering and Biophysics Program, University of California, Berkeley; Department of Ophthalmology, University of
California, San Francisco; Department of Ophthalmology and Visual Sciences, Washington University School of
Medicine in St. Louis; Department of Physics and Astronomy, San José State University; Chan-Zuckerberg Biohub, San
Francisco, CA
High-quality,wide-fieldretinalimagingisavaluable
methodtoscreenpreventable,vision-threatening
diseasesoftheretina.
Smartphone-basedretinalcamerasholdpromise
for increasingaccesstoretinalimaging,butvariable
imagequalityandrestrictedfieldofviewcanlimit
theirutility.Wedevelopedandclinicallytesteda
smartphone-basedsystemthataddressesthese
challengeswithautomation-assistedimaging.
TheCellScopeRetinasystemwasdesignedto
improvesmartphoneretinalimagingbycombining
automated fixationguidance,photomontage,and
multi-coloredilluminationwithoptimizedoptics,
user-testedergonomics,andtouch-screen
interface.Systemperformancewasevaluatedfrom
imagesofophthalmicpatientstakenby non-
ophthalmicpersonnel.
Thefixationtarget is translated througha series
ofpositions, re-orienting the patient’s eyes and
retina in arapid and controllable fashion.
CellScope Retina was
capable of capturing and
stitching montage wide-
field, 100-degree images
of a broad variety of retinal
pathologies in the
nonoptimal imaging
conditions of an ophthalmic
consultation service and
emergency department
setting.

34. Phantom
development for
retinal imaging
January2018
QuantifyingRetinalAreainUltra-Widefield
ImagingUsinga3-DimensionalPrintedEye
Model
https://doi.org/10.1016/j.oret.2017.03.011
Design of the model eye with an axial length of 24 mm with section A-A
representing the coronal plane and section B-B, the sagittal plane (top left). The
radius of the model is 13 mm (top right). The walls of the model eye have a
thickness of 2 mm. Each model is made up of multiple rings centered at the
posterior pole with each ring separated by 9 as in the image. The top right image
represents the sagittal plane and bottom left image represents the coronal plane.
Thebottomrightimagerepresents the model eyeviewed externally.
The grids in the original
image (left) is traced using
Photoshop CS2 (Adobe,
San Jose, CA; middle). In
this example, the line
thickness is set at 5 pixels
for ease of the reader;
however, in determining the
area, this was set at 1 pixel
for increased accuracy. The
traced image which was
used to determine the area
of each ring in pixels using
ImageJ(bottom).

35. Wide-field
fundus image
quality in
clinical practice
2016
PosteriorSegmentDistortioninUltra-
WidefieldImagingComparedto
ConventionalModalities
https://doi.org/10.3928/23258160-20160707-06
NationalInstitutefor HealthResearchMoorfieldsBiomedicalResearch Centre, MoorfieldsEyeHospital
andUniversityCollegeLondonInstitute ofOphthalmology, London
2017
Canultra-widefieldretinalimagingreplace
colourdigitalstereoscopyforglaucoma
detection?
https://doi.org/10.1080/09286586.2017.1351998
In conclusion, this study demonstrated almost
perfect agreement between colour digital
stereoscopy and the Optomap, an ultra-wide
field imaging technique when assessed by a
glaucoma specialist. It also showed the UWF
technique was reproducible in VCDR estimates.
Our data suggest that UWF imaging may be
suitable for diagnosing glaucoma in situations in
which slit-lamp biomicroscopy or digital colour
stereoscopy are not available and further research
about the comparative diagnostic performance of
UWF and other imaging technologies may be
warranted.
2018
Peripheral Retinal Imaging Biomarkers for
Alzheimer’s Disease: A Pilot Study?
https://doi.org/10.1159/000487053
Whether ultra-widefield (UWF, Optos P200C AF)
retinal imaging can identify biomarkers for
Alzheimer’s disease (AD) and its progression. …
after clinical progression over 2 years,
suggesting that monitoring pathological changes in
the peripheral retina might become a valuable tool
inADmonitoring.
The proposed averaging of images taken 90° apart can
improve the quality of the images obtained using the Optos
system. An acknowledgment and correction of this posterior
segment distortion will increase the accuracy that the
revolutionaryOptossystem hastooffer.

36. Clinical Reviews April2016
ULTRA-WIDEFIELDFUNDUSIMAGING:A
Reviewof ClinicalApplicationsandFuture
Trends
http://doi.org/10.1097/IAE.0000000000000937
Over the last 40 years, several innovative
approaches to wide-angle fundus imaging have
been introduced. These include the Pomerantzeff
camera,the Panoret-1000,the RetCam,andvarious
contact and noncontact lens-based systems.
These instruments can provide 100° to 160°
panoramic photographs using either traditional
fundusphotographyor confocalSLO(cSLO).
A major disadvantage of several of these
approaches, including the Pomerantzeff camera,
the Panoret-1000, the RetCam, and the Staurenghi
lens, is the utilization of a contact lens which
requires a skilled photographer to hold the
cameraandlensinplaceduringimageacquisition
A major source of frustration for retinal
physicians has been the difficulty associated with
creating fundus drawings in these electronic
systems (EHR). A potential solution would be the
seamless integration of an UWF color or
angiographic image into the examination note that
could be supplemented with annotations by
thephysiciantonotetheimportantfindings.
Schematic illustration
of ultra-widefield
imaging (Optos)of the
retinausing an
ellipsoidalmirror.
A laser light source is
reflected off the
galvanometer mirrors
ontoan ellipsoidal mirror.
The second focal point of
the mirror resideswithin
the eye, which facilitates
image acquisition anterior
totheequator.
Optosultra-widefield fluorescein
angiographyof proliferative
diabetic retinopathy. Right (A)
and left (B)eyesof apatient
with scattered microaneurysms,
peripheral capillary
nonperfusion, and focal leakage
consistent with
neovascularization elsewhere.
The peripheral
neovascularization and
nonperfusionare not
detectable using traditional
seven-field fundusimaging(C
and D).

37. Deep learning
with wide-field
retinal imaging
2017
Accuracyofdeeplearning,amachine-
learningtechnology,usingultra–wide-field
fundusophthalmoscopyfordetecting
rhegmatogenousretinaldetachment
https://doi.org/10.1038/s41598-017-09891-x
Thisstudyhadseverallimitations.Whenclarityof
theeyeisreducedbecauseofseverecataractor
densevitreoushaemorrhage,capturingimages
withOptosbecomeschallenging;thus,suchcases
werenotincludedinthisstudy.
July2018
Deep-learningClassifierWithanUltrawide-
fieldScanningLaserOphthalmoscope
DetectsGlaucomaVisualFieldSeverity
https://doi.org/10.1097/IJG.0000000000000988
To evaluate the accuracy of detecting glaucoma
visual field defect severity using deep-learning (DL)
classifier with an ultrawide-field scanning laser
ophthalmoscope.
May2018
Accuracyofultra-wide-fieldfundus
ophthalmoscopy-assisteddeeplearning,a
machine-learningtechnology,fordetecting
age-relatedmaculardegeneration
https://doi.org/10.1007/s10792-018-0940-0
AcombinationofDCNNwithOptosimagesisnot
betterthanamedicalexamination;however,itcan
identifyexudativeAMDwithahighlevelof
accuracy.Our systemisconsideredusefulfor
screeningandtelemedicine.

38. “Animal”
Fundus
Imaging
Optical
Designs

39. Modeling the
optics of the rat
eye with ZEMAX
April2011
Novelnon-contactretinacamerafortherat
and itsapplicationtodynamicretinalvessel
analysis
https://doi.org/10.1364/BOE.2.003094
A novel optical model of the rat eye was
developed for use with standard ZEMAX optical
design software, facilitating both sequential and
non-sequential modes. A retinal camera for the
rat was constructed using standard optical and
mechanical components. The addition of a
customized illumination unit with Xenon fiber-
coupled light source and existing standard software
enableddynamicvesselanalysis.

40. Optimizing
fundus image
quality for a rat
model
λpeak
= 580 nm
hbw = 19 nm
October2015
Investigatingtheinfluenceof chromatic
aberrationandopticalillumination
bandwidthonfundusimaginginrats
https://doi.org/10.1117/1.JBO.20.10.106010
Noninvasive, high-resolution retinal imaging of
rodent models is highly desired for longitudinally
investigating the pathogenesis and
therapeutic strategies. However, due to severe
aberrations, the retinal image quality in
rodents can be much worse than that in
humans.
We numerically and experimentally investigated the
influence of chromatic aberration and optical
illumination bandwidth on retinal imaging. We
confirmed that the rat retinal image quality
decreased with increasing illumination bandwidth.
We achieved the retinal image resolution of 10 μCube: A Framework for 3D Printable Optomechanicsm
using a 19 nm illumination bandwidth centered
at580nminahome-builtfunduscamera.
Furthermore, we observed higher chromatic
aberration in albino rat eyes than in pigmented
rat eyes. This study provides a design guide for
high-resolution fundus camera for rodents. Our
method is also beneficial to dispersion
compensation in multiwavelength retinal imaging
applications.

41. Contact lenses
for water-
immersion
imaging
July2018
Effectofacontactlensonmouseretinalin
vivoimaging:Effectivefocallengthchanges
and monochromaticaberrations
https://doi.org/10.1016/j.exer.2018.03.027
For in vivo mouse retinal imaging, especially with
Adaptive Optics instruments, application of a
contactlens (withGelTeal)isdesirable,asitallows
maintenance of cornea hydration and helps to
prevent cataract formation during lengthy
imaging sessions.
However, since the refractive elements of the eye
(cornea and lens) serve as the objective for most in
vivo retinal imaging systems, the use of a contact
lens, even with 0 Dpt. refractive power, can alter
thesystem'sopticalproperties.
In this investigation we examined the effective
focal length change and the aberrations that
arisefromuseofacontactlens.
Based on the ocular wavefront data we evaluated
the effect of the contact lens on the imaging system
performance as a function of the pupil size. These
results provide information for determining
optimum pupil size for retinal imaging without
adaptive optics, and raise critical issues for
design of mouse optical imaging systems
thatincorporatecontactlenses.
The effect of a contact lens and
gel on ocular aberration is
complex. In our system, the use
of a contact lens introduced
vertical coma and spherical
aberrations above those of the
native eye.

42. Tunable goggle
lens for rodent
models
July2017
Opticalmodellingofasupplementary
tunableair-spacedgogglelensforrodent
eyeimaging
https://doi.org/10.1371/journal.pone.0181111
In this study, we present the concept of a tunable
goggle lens, designed to compensate individual
ocular aberration for different rodent eye powers.
Ray tracing evidences that lens-fitted goggles
permit, not only to adjust individual eyes
power, but also to surpass conventional adaptive
correction technique over large viewing angle,
provided a minimum use of two spaced liquids. We
believe that the overlooked advantage of the
3D lens function is a seminal finding for further
technological advancements in widefield retinal
imaging.
Example of a multi-element lens-fitted goggle rigidly fastened
to an optical system: The goggle lens having a corneal matching
index (see Jianget al. 2016 for details) is made of a plurality of liquid
filled cavities, having a distinct refractive index, separated by elastic
surface membranes that enable a static correction of the eye by
restructuration of therodent cornea.

43. Improving
contact lens
modelling itself
for all imaging
studies
2018
Nonpupiladaptiveopticsforvisual
simulationofacustomizedcontactlens
https://doi.org/10.1364/AO.57.000E57
We present a method for determining the
deformable mirror profile to simulate the optical
effect of a customized contact lens in the central
visual field. Using nonpupil-conjugated adaptive
optics allows a wider field simulation compared to
traditional pupil-conjugated adaptive optics. For a
given contact lens, the mirror shape can be derived
analytically using Fermat’s principle of the
stationary optical path or numerically using
optimization in ray-tracing programs such as
Zemax.
Diagramoftheasphericcontactlensand
schematiceyemodel.

44. “Video-based”
Fundus
Imaging
Optical
Designs

45. Can’t really use
flashes of visible
light
Pupilconstrictsfromtheflash,and
dynamicpupillometrycanbe donewith
theflashofcommercialfunduscameras
(seeright )→)
Notaproblemunlessyoualwaysimage
throughthecentral2mm pupilfor
example (MaxwellianOptics)
2018
PupillaryAbnormalitieswithVarying
SeverityofDiabeticRetinopathy
https://doi.org/10.1117/12.2036970
Mukesh Jain, Sandeep Devan, DurgasriJaisankar,
GayathriSwaminathan, ShahinaPardhan & Rajiv Raman
Pupil measurements were performed with an
1/3 inch infrared camera and flash light (10 ws
xenon flash lamp, OrionFundusCamera,
Nidek Technologies,Italy).
SpectralPower DistributionofCanonSpeedlite540EZconsumer Xenonphotographicflash
SPDat
Fullintensity(1/1)
Xenon flashes are typically
powered by capacitor
banks. The more capacitors
involved, the higher the time
constant, thus longer the
flashduration
http://www.fredmiranda.co
m/forum/topic/1485638
13– Xenon flashtubeon funduscameradesign
http://doi.org/10.1167/iovs.12-10449
KennethTran;ThomasA. Mendel;KristinaL. Holbrook;PaulA.Yates

46. Either
continuous IR
lighting or
optical design
to cope with the
small light-
adapted pupil
2004
Observationof theocularfundusbyan
infrared-sensitivevideocameraafter
vitreoretinalsurgeryassistedby
indocyaninegreen
https://www.ncbi.nlm.nih.gov/pubmed/12707597
F-10 confocal digital ophthalmoscopefrom NIDEK
http://usa.nidek.com/products/scanning-laser-ophtha
lmoscope/
Downside:Near-infraredvideodoesnot
necessarilycaptureallthefeaturesofthe
fundus
2008
US20100245765A1Videoinfrared
ophthalmoscope
https://patents.google.com/patent/US20100245765/en
David S. DYER, JamesHiggins
Dyer HoldingsLLC
March2016
FundusPhotographyinthe21stCentury
—AReviewofRecentTechnological
AdvancesandTheirImplicationsfor
WorldwideHealthcare
https://doi.org/10.1089/tmj.2015.0068
Nishtha Panwar, Philemon Huang, Jiaying Lee, Pearse A. Keane, TjinSwee
Chuan, Ashutosh Richhariya, Stephen Teoh, Tock HanLim, and Rupesh
Agrawal
OculusImagecam2 DigitalSlitLampCamera Different segments ofthe
eye, such as anterior segment, fundus, sclera, etc., canbeconveniently
imaged bysetting suitable exposure time, lightmagnification, and white
balance. Additional videosequences can be recorded bythe high-
resolution, digital video camerain the beam pathofthe slitlamp.
Volk Pictor enables nonmydriatic fundus examination with an improved 40°
FoV. It has modifications allowing still images and videos of the optic disc,
macula, and retinal vasculature.
The Horus Scope from JedMed (St. Louis, MO) is a hand-held
ophthalmoscopic adaptor for viewing the retina and capturing video and still
images thatcan be easilytransferred to thepersonal computer
Riester Ri-Screen Multifunctional Digital Camera System This slit
lamp-based system, along with attachable ophthalmoscopic lens, enables
retinal ophthalmic imaging and nonmydriatic eye fundus examination. The
Riester (Jungingen, Germany) Ri-Screen provides digital images and video to
support screeninganddocumentation ofocular lesions and anomalies.
Smarphone-based approach from Harvard Medical School, Boston (
Haddock et al. 2013), They used the iPhone camera's built-in flash for acquiring
images and an external 20D lens for focusing. They used the Filmic Pro app
(£5.99) for control of light intensity, exposure, and focus. A Koeppe lens was
used for imaging patients under anesthesia. Still images were then
retrieved from the recorded video (like with D-Eye). When imaging the
fundus ofrabbits, 28D or30D lenses haveshown togivebetterresults.

47. Stripe-field
method
SPIEBiOS,2014
Non-mydriatic,widefield,fundusvideo
camera
https://doi.org/10.1117/12.2036970
Bernhard Hoeher;Peter Voigtmann; GeorgMichelson;
Bernhard Schmauss
We describe a method we call "stripe field
imaging" that is capable of capturing wide
field color fundus videos and images of the
humaneyeatpupilsizesof2mm.
We designed the demonstrator as a low-cost
device consisting of mass market
components to show that there is no major
additional technical outlay to realize the
improvements we propose. The technical
core idea of our method is breaking the
rotational symmetry in the optical design that is
giveninmanyconventionalfunduscameras.
By this measure we could extend the possible
field of view (FOV) at a pupil size of 2mm
from a circular field with 20° in diameter to a
square field with 68° by 18° in size. We
acquired a fundus video while the subject
was slightly touching and releasing the lid. The
resulting video showed changes at vessels in
the region of the papilla and a change of the
palenessofthepapilla.
Stripe-field method: 1st and 2nd Purkinje Reflections
focused to unused lower black stripe; 4 th Purikinje reflection
focused to upper unused stripe; gaining unlimited width of the
fieldofviewinthecenter

48. Binocular
Opthalmoscope
2017 SPIE
Binocularvideo ophthalmoscope
forsimultaneous recording of
sequencesof the humanretina to
compare dynamicparameters
https://doi.org/10.1117/12.2282898
RalfP.Tornow,AleksandraMilczarek,Jan
Odstrcilik,andRadimKolar
A parallel video ophthalmoscope was
developed to acquire short video
sequences (25 fps, 250 frames) of both
eyes simultaneously with exact
synchronization.
Video sequences were registered off-line
to compensate for eye movements. From
registered video sequences dynamic
parameters like cardiac cycle
induced reflection changes and eye
movements can be calculated and
compared between eyes.

49. Concept design of
what portable
binocular fundus
camera could
look like
Doesnothurtatall to thinkabouttheUX
for the end-user(clinician,non-trained
operatorwho couldbethepatientor an
opticianfor example)
Naturallythisdoesnotexcludetheneed
for goodopticaldesignandgood
computational imageenhancement.
Combinetheseallintoonesolution,and
you willhave asuccessfulbusinessthat
bringsactualvalue to the patientsinstead
of the oftenover-hyped“startup value”
2018
KoreanstartupROOTEEHEALTH
“ELI (Eye-Linked-Information), a wearable fundus camera
possesses an auto-shot feature which removes the need for
manually adjusting the camera to focus on the retina. This
removes the need for patients to undergo taking several photos
with flashes. With the use of ELI, patients previously undiagnosed
or lost in between their ‘first’ diagnosisof diabetes andlater arising
diabetic complications related to the eye will be possible to
prevent. Providing the Internal Medicine department the tool to
diagnose diabetic retinopathy is crucial as timing for treatment
mustbeinearlystages.
There'sagapbetweenfirstprototypeandELI.wewanttoimprove
cost-effectiveness and accuracy by using adaptive optics & deep
learningtechnology”

50. “Custom”
Fundus
Imaging
Optical
Designs

51. Fundus imaging
for Stiles-
Crawford effect
2017SPIE
Developmentofafunduscamerafor
analysisofphotoreceptordirectionality
inthehealthyretina
http://hdl.handle.net/10362/15618
Author: Anjos,Pedro Filipedos Santos;
Advisors: Vohnsen,Brian; Vieira,Pedro
The Stiles-Crawford effect (SCE) is the well-known
phenomenon in which the brightness of light
perceived by the human eye depends upon its
entrancepoint in thepupil.
Retinal imaging, a widely spread clinical practice,
may be used to evaluate the SCE and thus serve as
diagnostic tool.
Nonetheless, its use for such a purpose is still
underdeveloped and far from the clinical reality.
In this project a fundus camera was built and used to
assess the cone photoreceptor directionality
by reflective imaging of the retina in healthy
individuals.
Diagramofthefinalsystem.
1–Illuminator;
2–OpticalFibre;
3–MillimetricalStage;
4–RedFilter;
5–IrisDiaphragm;
6–MaxwellianLens;
7–Beamsplitter;
8–ImagingLens;
9–ZoomLens;
10–Sensor;
11–DesktopComputer.

52. “Novel”
Fundus
Imaging
Optical
Designs

53. Inspiration for
compact
ophthalmic
imaging designs
Trans-epidermal
illumination
Quantitativephaseimagingofretinalcells
https://arxiv.org/abs/1701.08854
Bycollectingthescatteredlight through
thepupil,thepartiallycoherent illumination
producesdarkfieldimages,whichare
combinedtoreconstruct a quantitative
phaseimagewithtwicethenumerical
aperturegivenbytheeye'spupil. Wethen
report,to ourknowledge,thevery first human in
vivophaseimagesofinnerretinalcellswithhigh
contrast.
a. Trans-epidermal illumination
by means of flexible PCB containing
LEDs placed in contact with the skin
of the eyelid. Light is then transmitted
inside the eyeball. After scattering off
the eye fundus, the light passing
through the retinal’s cell layers is
collected by the eye lens. b. Flexible
PCB holding 4 red LEDs. c.
Recording and reconstruction
procedure for in-vivo measurement.
d. Experimental setup. The light
scattered from the retina is collected
by lens L1. The 4f system composed
of the lenses L1 and L2 is adjusted for
defocus thanks to a badal system.
The lens L2 forms an image of the
pupil plane at its focal distance, while
the lens L3 forms an image of the
retina on the EMCCD camera. Dic:
dichroic mirror. Synchronization
between the LEDs and the camera is
performed thanks to a programmable
board. -TimothéLaforestetal. (2017)
Illumination of the retinal layers
provided by transcleral
illumination. The light is first
transmitted through sclera, RPE
and retina. After travelling through
the aqueous humor it impinges on the
RPE. Herebackscattering off the RPE
generates a new illumination beam.
This secondary illumination
provides a transmission light
propagating through the translucent
layers of the retina which is then
collected by the pupil. Azimuthal
angle and polarangle .θ and polar angle α. α.

54. Trans-palpebral
illumination
Paper 1
Trans-palpebralillumination:anapproachfor wide-angle
fundusphotographywithout theneedfor pupildilation
DevrimToslak, Damber Thapa, Yanjun Chen,MuhammetKazimErol, R. V.PaulChan,
and Xincheng Yao https://doi.org/10.1364/OL.41.002688
Optics Letters Vol. 41, Issue 12, pp. 2688-2691 (2016)
“Retinal field-of-view (interior angle of 152°,
and exteriorangle 105°”
Digitalsuper-resolution
algorithms are alsobeing
considered for further resolution
improvements [Thapa et al.2014]
. In
addition tothe smartphone-
based prototype imagingdevice,
we are currentlyconstructinga
benchtop prototype for testing
the feasibilityof wide-angle
fluorescein angiography
employingthetrans-palpebral
illumination

55. Trans-pupillary
illumination
Paper 2
Near-infraredlight-guided miniaturizedindirect
ophthalmoscopyfornonmydriaticwide-field fundus
photography
DevrimToslak, Damber Thapa, Yanjun Chen,MuhammetKazimErol, R. V.PaulChan,
and Xincheng Yao https://doi.org/10.1364/OL.41.002688
Optics Letters Vol. 41, Issue 12, pp. 2688-2691 (2016)

56. Trans-pars-
planar
illumination
Contact-freetrans-pars-planarilluminationenablessnapshot funduscamera fornonmydriatic widefeld
photography
BenquanWang,DevrimToslak,Minhaj Nur Alam, R.V. Paul Chan&Xincheng Yao https://doi.org/10.1038/s41598-018-27112-x
Scientific Reports volume 8, Article number:8768 (2018)
Panoret-1000™ employed trans-scleral illumination to image the retina from the optic disc to the ora serrata in a single-shot image (Shields et al. 2003). However, clinical deployment of trans-scleral
illumination was not successful, and the product Panoret-1000™ is no longer commercially available. Clinical deployment of trans-scleral illumination failed due to several limiting factors. First,
the employed contact-mode imagingwas not favorable for patients. Direct contact of the illuminating and imaging parts to the eyeball might produce potential inflammation, contamination,
and abrasion to the sclera and cornea. Second, it was difficult to operate the system to obtain good retinal images. In Panoret-1000™, the digital camera and light illuminator were apart from
each other. To capture a retinal image, one hand was used to operate the camera, and the other hand was used to adjust the light illuminator. The simultaneous need of both hands for imaging
operation madethe deviceverydifficulttouse.
Insteadofusingalightilluminator
contacting theeyelid(trans-palpebral
illumination)13
or sclera(trans-scleral
illumination)10,11
trans-pars-planar
illuminationistotallycontact-
freetoprojectilluminatinglight
throughtheparsplana.
Representative fundus images with illumination at different locations. (a) Illustration of different
illumination locations. (b) Fundus images acquired at different illumination locations. b1-b3 were acquired at
corresponding locations P1-P3 in panel a. (c) Average intensity of fundus images collected with constant power
illumination delivered through different locations. The curve is an average of 5 trials from one subject. Gray shadow
shows standard deviation. P1-P3 corresponds to images b1-b3. (d) Red, green and blue channels of the fundus
image b2. (e) Normalized fundus image b2, with digital compensation of red and green channel intensities. Macula,
opticdisc,nervefiber bundlesandbloodvesselscouldbeclearlyidentified.

57. Retinal Imaging
Illumination
Summary
https://doi.org/10.1038/s41598
-018-27112-x
Schematicillustrationofdifferentilluminationschemesforretinalimaging.
trans-pupillary
illumination
trans-scleral
illumination
trans-palpebral
illumination
trans-pars-planar
illumination
Alenswasusedtoimagetheapertureontothe
scleratoforman arc-shapedillumination
pattern.Theilluminationaperturewas
carefullydesignedtocloselymatchtheshape
oftheparsplana.Theendoftheilluminating
armthatwasclosetoeyecouldbemanually
movedinahorizontaldirectionbya
translationstagetopreciselydeliver
illuminationlighttotheparsplana.Lightpassing
throughtheparsplanawasdiffusedand
illuminatedtheintraocular areahomogenously.

58. Transcranial
Illumination
Artifacts causedbyretinalsurfacereflexareoften
encountered,whichcomplicatequantitative
interpretationofthereflectionimages.Wepresentan
alternativeilluminationmethod,whichavoids
theseartifacts.Themethodusesdeeplypenetrating
near-infrared(NIR)lightdeliveredtranscranially
fromthesideofthehead,andexploitsmultiple
scatteringtoredirectaportionofthelighttowardsthe
posterioreye
August2018
Non-mydriaticchorioretinalimaging
inatransmissiongeometryand
applicationtoretinaloximetry
doi:10.1364/BOE.9.003867
TimothyD.WeberandJeromeMertz
BostonUniversity
Project: Transcranialretinalimaging
A: Schematic of fundus transillumination and imaging. LEDs at several central wavelengths ( N ) are imaged via couplingλ
optics (CO), comprised of lenses f 1 and f 2 , onto theproximalend of aflexiblefiberbundle(FB). A commericalfunduscamera
(FC) images the transilluminated fundus onto a camera (CCD). B: Example raw image recorded on the CCD. C: Normalized
measuredspectraofavailable high-power deepredandNIRLEDs.
This unique transmission geometry simplifies absorption measurements and enables flash-free, non-mydriatic
imaging as deep as the choroid. Images taken with this new transillumination approach are applied to retinal
oximetry.

59. Aplanat
Fundus
Imaging
June2018
FundusImagingusingAplanat
https://doi.org/10.1080/24699322.2017.1379143
VishwanathManik Rathod,M.Sc.Thesis
IndianInstituteof Technology Hyderabad
In this thesis, we suggest an alternative optics
for fundus imaging. Design constraints of
aplanat helps to remove all major
aberrations observed by lens without adding
any extra corrective measures as like those of
lens optical systems. And since the proposed
system does not have complex set of lenses,
complications of the system are and helps in
reductionofcostsignificantly.
Major advantage of the system is it offers wide
numerical aperture large field of view and
systemsize remainsto thatofhandhelddevice.
Large NA and high radiation efficiency abolish
the need of pupil dilation making process
painlessforpatient.
Process follows as coordinates in MATLAB exported to Solid Edge
where aplanat reflector in CAD object form was made then
imported in Zemax. Zemax supports four CAD formats: STL, IGES,
STEP and SAT. Of these, only STL uses facets to represent the
object: the other three model the object as a smooth, continuous
surfaceshape.
Stepsin Solid Edge
In order to image retina completely, 3 phases of imaging need to be done.
Narrow field aplanat will be used to image the part near to optical axis of eye.
Wide throat aplanat will be used to image peripheral region. Hole at center
remained undetected through aplanat can be imaged using normal lens system.
Sofinal solution istoimage:
Exploiting the
overlapping partin the
imagesfromall the
system,stitching
algorithmcan beused
later to forma
completeimage. This
systemleadsto total
FOV of200˚

60. Freeform Optics
Fundus
Imaging?
May2018
Startinggeometrycreationand design
method forfreeformoptics
https://doi.org/10.1038/s41467-018-04186-9
AaronBauer,EricM.Schiesser &Jannick P.Rolland
May2018
Over-designedandunder-performing:
designandanalysisofafreeformprism
viacarefuluseoforthogonalsurface
descriptions
https://doi.org/10.1117/12.2315641
NicholasTakaki; WanyueSong;AnthonyJ.Yee; JulieBentley;
DuncanMoore;Jannick P.Rolland
- Instituteof Optics,Univ.of Rochester
http://focal.nl/en/#technology
Medical Optical Systems
DEMCONFocal
Institutenweg25A
7521 PH Enschede
May2018
DesignofFreeformIlluminationOptics
https://doi.org/10.1002/lpor.201700310
Rengmao Wu ZexinFeng Zhenrong Zheng Rongguang Liang
Pablo Benítez JuanC.Miñano,FabianDuerr
Reviewfocuseson thedesign of freeformillumination optics, which
isakey factorinadvancing thedevelopmentof illumination
engineering.
May2018
High-performanceintegral-imaging-
basedlightfieldaugmentedreality
displayusingfreeformoptics
https://doi.org/10.1364/OE.26.017578
HekunHuang andHong Hua

61. Freeform Optics
forCorneal
Imaging
2017
Freeformopticaldesignfora
nonscanningcornealimagingsystem
withaconvexlycurvedimage
https://doi.org/10.1364/AO.56.005630
Yunfeng Nie,HerbertGross,Yi Zhong,andFabianDuerr
“Thelateralresolutiononthecorneaisabout10 μCube: A Framework for 3D Printable Optomechanicsm
withgoodmodulationtransferfunction(MTF)andspot
performance.Toeasetheassembly,amonolithicdesignis
achievedwithslightlylowerresolution,leadingtoapotential
massproductionsolution.”

62. Additive
Manufacturing
Optics
Fundus
Imaging?
3DPrintingoptics
inotherwords
June2018
3Dprintedphotonicsandfree-form
optics
http://www.uef.fi/en/web/photonics/3d-printed-pho
tonics-and-free-form-optics
http://optics.org/news/4/6/8
JyrkiSaarinen,Jari Turunen(design),Markku Kuittinen,Anni
Eronen,Yu Jiang,Petri Karvinen,VilleNissinen,Henri Partanen,
PerttiPääkkönen,Leila Ahmadi,RizwanAli,BisratAssefa,Olli
Ovaskainen,DipanjanDas,MarkkuPekkarinen
Dutch start-up LUXeXceL has invented the
Printoptical® technology for 3D printing optical
elements. Their technology is based on an
inkjet printing process. In collaboration with
Luxexcel, University of Eastern Finland will
furtherdevelopthePrintoptical®technology.
June2016
Additivemanufacturingofoptical
components
https://doi.org/10.1515/aot-2016-0021
Andreas Heinrich /Manuel Rank/Philippe Maillard/Anne Suckow /Yannick
Bauckhage /PatrickRößler /Johannes Lang /Fatin Shariff/Sven Pekrul
The additive manufacturing technology offers a high potential in the
field of optics as well. Owing to new design possibilities, completely
new solutions are possible. This article briefly reviews and
compares the most important additive manufacturing methods for
polymer optics. Additionally, it points out the characteristics of
additive manufactured polymer optics. Thereby, surface quality
is of crucial importance. In order to improve it, appropriate post-
processing steps are necessary (e.g. robot polishing or coating),
which will be discussed. An essential part of this paper deals with
various additive manufactured optical components and their use,
especially in optical systems for shape metrology (e.g. borehole
sensor, tilt sensor, freeform surface sensor, fisheye lens). The
examples should demonstrate the potentials and limitations of
optical componentsproduced byadditivemanufacturing.
Feb2018
Additivemanufacturingofreflectiveandtransmissive
optics:potentialandnewsolutionsforopticalsystems
https://doi.org/10.1117/12.2293130
A.Heinrich; R.Börret; M.Merkel;H.Riegel
Additive manufacturing enables the realization of complex shaped parts. This also provides a high
potential for optical components. Thus elements with virtually any geometry can be
realized, which is often difficult with conventional fabrication methods. Depending on the
material and thus the manufacturing method used, either transparent optics or reflective optics
canbedeveloped with theaid of additivemanufacturing.
Our aim is to integrate the additive manufactured optics into optical systems.
Therefore we present different examples in order to point out new possibilities and new solutions
enabled by 3D printing of the parts. In this context, the development of 3D printed reflective and
transmissiveadaptiveopticswill bediscussed aswell.

63. Depth-
resolving
Fundus
Imaging
Optical
Designs

64. Fundus
Stereo
Imaging
2008
Quantitativedepthanalysisofoptic
nerveheadusingstereoretinalfundus
imagepair
http://doi.org/10.1117/1.3041711
Toshiaki Nakagawa,Takayoshi Suzuki,Yoshinori Hayashi,Tetsuya
Yamamoto etal..
Convergentvisualsystemfor depthcalculationof
stereoimagepair.
March2014
3Dpapillaryimagecapturingbythestereo
funduscamerasystemforclinicaldiagnosis
onretinaandopticnerve
https://doi.org/10.1117/12.2038435
Danilo A.Motta;AndréSerillo; Luciana deMatos; Fatima M.M.Yasuoka;
Vanderlei SalvadorBagnato; LuisA.V.Carvalho
2012
QuantitativeEvaluationofPapilledemafrom
StereoscopicColorFundusPhotographs
http://doi.org/10.1167/iovs.12-9803
Li Tang; Randy H.Kardon; Jui-Kai Wang; MonaK.Garvin; Kyungmoo Lee;
MichaelD.Abràmoff
Comparison of ONH shape estimates from stereo fundus
photographs and OCT scans using topographic maps. (A) Reference
(left) fundus image wrapping onto reconstructed topography as output
from stereo photographs. Small squares with different colors are marked
at four corners of the reference image, indicating the orientation of retinal
surface rendering. (B) Fundus image wrapping onto reconstructed
topography asoutputfromtheOCTscansfromthesameviewangle.

65. Fundus
Stereo
Imaging #2
2015
All-in-focusimagingtechniqueused toimprove3Dretinalfundusimagereconstruction
https://doi.org/10.1145/2695664.2695845 |https://doi.org/10.1117/12.2038435
DaniloMotta,LucianadeMatos,AmandaCaniattodeSouza,RafaelMarcato,AfonsoPaiva,LuisAlbertoVieirade
CarvalhoR&D– Wavetek; UniversidadedeSão Paulo,SãoCarlos, SP,Brazil

66. Snapshot
stereo fundus
systems
2017
Designof opticalsystemforbinocular
funduscamera
https://doi.org/10.1080/24699322.2017.1379143
JunWu,Shiliang Lou,Zhitao Xiao,Lei Geng,Fang Zhang,Wen
Wang &Mengjia Liu
Anon-mydriasisopticalsystemforbinocular
funduscamerahasbeendesignedinthis
paper.Itcancapturetwoimagesofthesame
fundusretinalregionfromdifferentanglesatthe
sametime,andcanbeusedtoachievethree-
dimensionalreconstructionoffundus.
According to requirements of
medical light source, sodium
lamp whose wavelength is 589
nm is selected as light source
and its spectral range is 560-
610 nm; Magnifying power of
the imaging system is 1.07, and
the cut-off frequency of object
is 96.3pl/mm, that is our
system can distinguish the
structure unit of 5.2 μm. In
order to make operation and
adjustment more convenient,
the size of this optical system is
set to be 480 mm x 100 mm x
200mm.
Diagramofimagingsystem.

67. 3D fundus with
aplanats
2018
3DImageReconstructionofRetina
usingAplanats
http://raiith.iith.ac.in/id/eprint/4109
SankrandanLoke and SoumyaJana
Mastersthesis,IndianInstituteof TechnologyHyderabad
Theraytracingprogramiswrittenin Python,with
assistancefromtheMATLABtoolboxOptometrika
3Deyemodel
3Dplotofeye,aplanatand itssensor
A very high resolution 3D retina is constructed using the Meshlab software.
This is considered as the digital version of painted retina to be imaged. A
hemi-spheroidal shaped, high density point cloud is created and normals are
calculated at each point. Then ”screened Poisson Surface Reconstruction”
filter is applied on it to create a mesh over the point cloud. The resultant mesh
iscleaned and theface-normalsand vertex-normalsarenormalized.

68. Plenoptic
Fundus
Imaging
Optical
Designs

69. PlenopticFundus
Imaging
Idea been around for
some time now
2011
US20140347628A1
Multi-view funduscamera
Inventor:ASOCIACION INDUSTRIAL DE OPTICA,
COLOR E IMAGEN -AIDO;UniverstitatdeValencia
CurrentAssigneeASOCIACIONINDUSTRIAL DE
OPTICA COLOR E IMAGENASOCIACIONINDUSTRIAL
DE OPTICA COLOR E IMAGEN- AIDO Universtitatde
Valencia
2011
US8814362B2
Method forcombininga plurality of
eyeimagesinto aplenoptic
multifocalimage
Inventor:Steven Roger Verdooner
CurrentAssignee : Neurovision ImagingInc
2011
US8998411B2
Light field camera for fundus
photography
Inventor:Steven Roger Verdooner Alexandre R.
Tumlinson, Matthew J. Everett
CurrentAssignee : Carl Zeiss Meditec Inc
2013
US9060710B2I
System and method for ocular
tomography using plenopticimaging
Inventor Richard J. Copland
CurrentAssigneeAMOWavefront Sciences LLC
2015
US9955861B2
Constructionof an individualeye
model using aplenopticcamera
Inventor Liang Gao, IvanaTosic
CurrentAssigneeRicoh Co Ltd
US8998411B2US8998411B2: ”As described by RenNg (founder of Lytro),
the “light field” is a concept that includes both the position and
direction of light propagating in space (see for example
U.S.Pat.No.7,936,392). “
DeHoog andSchwiegerling
“Funduscamera
systems: acomparative
analysis”
Appl. Opt.48, 221-228
(2009)
https://doi.org/10.1364/AO.4
8.000221

70. PlenopticFundus
Imaging
Short intro
Plenoptic imagingof theretina:
canitresolvedepthinscattering
tissues?
Richard Marshall, Iain Styles, ElaClaridge,and Kai
Bongs
https://doi.org/10.1364/BIOMED.2014.BM3A.60, PDF
Configurationsoftwo
differentplenoptic
cameras: (a) The
traditionalplenoptic
camera.(b)The
focusedplenoptic
camera.
“Plenoptic imaging has already proven its capabilities to determine depth and give 3D
topographic information in free space models, however no study has shown how it
would perform through scattering media such as the retina. In order to study
this, simulations were performed using MCML, a multi-layered Monte Carlo modeling
software[Wang etal.1995]. Theparameters characterising theproperties ofretinal layers
and used in MonteCarlo (MC)simulationhavebeen taken from Stylesetal.(2006).”
Simulationof Light Field
FundusPhotography
ShaTonand T.J. Melanson.
Stanford Courseassignment
http://stanford.edu/class/ee367/Winter
2017/Tong_Melanson_ee367_win17_rep
ort.pdf
Light Field Imagesfrom
Different ViewingPoints
Comparisonsbetween normal camera(L), light field
camera(M) and reference image (R)

71. PlenopticFundus
Imaging
Prototype System #1:
Moorfields Eye Hospital and
University College of London
Retinal fundus imaging with a plenoptic sensor
Brice Thurin; Edward Bloch; Sotiris Nousias; Sebastien Ourselin;
Pearse Keane; Christos Bergeles
https://doi.org/10.1117/12.2286448
Optical layout of the plenoptic fundus camera. A white LED
illuminates the eye fundus through a polarizer and polarizing
beamsplitter. The LED chip is conjugated with the eye pupil and an IRIS.
While the condensing lens L1 is conjugated with the retinal plane.A
primary image of the retinal is formed by a Digital Wide-Field lens L4.
This image is relayed to the plenoptic sensor (Raytrix R8) by L3 and L6
through the polarizing beamsplitter. The polarization helps reduce the
corneal reflex.
Plenoptic ophthalmoscopy has been
considered for eye examinations [Tumlinsonand Everett2011;
Bedard etal.2014; LawsonandRaskar2014]
A crude implementation
has been proposed by Adametal.(2016) the
system built is used as a substitute for a human
observer, only a small portion of the field is used for
fundus imaging and the it does not exploit the full
capabilities of light-field imaging. More recently a
plenoptic sensor has been used to successfully
characterize the topography of the healthy and
diseasedhumanirisinvivo[Chenetal.2017].

72. PlenopticFundus
Imaging
Prototype System #2a
:
Queensland University of Technology; Medical and
Healthcare Robotics, Australian Centre for
Robotic Vision, Brisbane; Institute of Health and
Biomedical Innovation, Brisbane
Glare-free retinal imaging using a portable light
field fundus camera
DouglasW.Palmer, ThomasCoppin,Krishan Rana, Donald G. Dansereau,MarwanSuheimat, Michelle
Maynard, David A. Atchison, JonathanRoberts,RossCrawford, and AnjaliJaiprakash
BiomedicalOpticsExpressVol. 9, Issue7,pp. 3178-3192(2018)
https://doi.org/10.1364/BOE.9.003178
Imaging path optical diagram of light field fundus camera.
Top row (A,B,C) represents a correctly designed system where
the entrance pupil diameter ØLF is smaller than the eye pupil ØP
and the region of the sensor under the microlens shows minimal
vignetting, where d is the number of pixels under a microlens
horizontally and vertically. Bottom row (D,E,F) represents an
incorrectly designed system where ØLF is larger than ØP. The
resultant micro image vignetting is shown in (F).(A) and (D) show
slices taken approximately through the iris of the eye. (B) and (D)
show the arrangements of components and paraxial
approximations of the ray paths for a point on (blue) and off-axis
(red).The design entrance and exit pupils are the images of the
design aperture stop as seen through theobjective and relay lenses
respectively.
Plenoptoscope - General arrangement. Imaging path in gray, eye fixation path in
red, illumination path in yellow. The Lytro Illum light field camera has an internal fixed
f/2.0 aperturestop (notshown).

73. PlenopticFundus
Imaging
Prototype System #2b
:
Queensland University of Technology; Medical and
Healthcare Robotics, Australian Centre for
Robotic Vision, Brisbane; Institute of Health and
Biomedical Innovation, Brisbane
Glare-free retinal imaging using a portable light
field fundus camera
DouglasW.Palmer, ThomasCoppin,Krishan Rana, Donald G. Dansereau,MarwanSuheimat, Michelle
Maynard, David A. Atchison, JonathanRoberts,RossCrawford, and AnjaliJaiprakash
BiomedicalOpticsExpressVol. 9, Issue7,pp. 3178-3192(2018)
https://doi.org/10.1364/BOE.9.003178
Series of images captured using the Retinal
Plenoptoscope. Images are shown in sets of two with
the top image being a standard (not glare-free)
render of the light field, and the bottom image being
a gray-scale relative depth map. Each depth map has
an associated scale that relates gray shade to depth.
Note that the leftmost set is of a model eye, the second
leftmost set is of a myopic eye (-5.75D), and the two
rightmost sets are ofemmetropiceyes.
An image of a human retina captured using the Retinal
Plenoptoscope with an associated epipolar image.
Annotations indicate areas of interest, where (A) and (C)
correspondtoglare,and(B)correspondstotheOpticDisk.
Series of images created using various light field rendering techniques. Images
are shown in sets of three with the left image being the central view from the
light field, the middle image being astandard render with noglare masking, and
the right image beingaglare-freerender.

74. PlenopticIris
Imaging
Prototype System
Mechanical Engineering; Department of
Ophthalmology and Visual Sciences; Department of
Human Genetics | University of Michigan
Human iris three-dimensional imaging at
micron resolution by a micro-plenoptic camera
Hao Chen, MariaA.Woodward, David T.Burke,V.SwethaE. Jeganathan, Hakan Demirci,andVolker Sick
BiomedicalOpticsExpressVol. 8,Issue10,pp.4514-4522 (2017)
https://doi.org/10.1364/BOE.8.004514 | researchgate
A micro-plenoptic system (Raytrix R29) was designed to capture the
three-dimensional (3D) topography of the anterior iris surface by simple
single-shot imaging. Within a depth-of-field of 2.4 mm, depth resolution of
10 µm can be achieved with accuracy (systematic errors) and precision
(randomerrors)below20%.

75. Multimodal
Imaging
Optical
Designs

76. Combined
Fundus and OCT
Imaging
2007
SimultaneousFundusImagingand
OpticalCoherenceTomographyofthe
MouseRetina
http://doi.org/10.1167/iovs.06-0732
OmerP.Kocaoglu;Stephen R.Uhlhorn; EleutHernandez;
RogerA. Juarez; Russell Will;Jean-MarieParel;Fabrice
Manns
To develop a retinal imaging system suitable for
routine examination or screening of mouse
models and to demonstrate the feasibility of
simultaneously acquiring fundus and optical
coherencetomography(OCT)images.
The mousewas held ina cylindrical holdermadefrom30-mL syringes. The positionofthe mouse was adjusted
to align the optical axis ofthe mouse eye with the axis ofthe deliverysystembyusing 6-μm screws.m screws.
Left: general optical design of the imaging system; right: the mouse fundus and OCT imaging system, including fundus imaging with a digital camera attached to the
photographic portof theslitlamp, theOCT beamdeliverysystem, thesix-axis mousepositioner,and theinterferometer.

77. Fundus Camera
Guided
Photoacoustic
Ophthalmoscopy
2013
FundusCameraGuidedPhotoacoustic
Ophthalmoscopy
https://doi.org/10.3109/02713683.2013.815219
Aschematicoftheimagingsystemdesigned
andoptimizedfor rateyesisshowninright→
A532-nmpulsed laser(Nd:YAGlaser,
SPOT-10-100,ElforlightLtd,UK;output
wavelength1064nm;pulseduration:2ns;
BBOcrystalforsecondharmonicfrequency
generation;CasTech,SanJose,CA) wasused
astheilluminationlightsourceforPAOM.
ThePAOMlaser(greenpath)wasscannedby
anx–ygalvanometer (QS-7,Nutfield
Technology)anddeliveredtotheposterior
segmentoftheeyeafter passingthrougha
relaylensL5(f=150mm)andanobjectivelens
OBJ1(f=30mm,VIS-NIRARcoated).Thefinal
laserpulseenergyonthecorneais60nJ,
whichisconsideredeye-safe.
TheinducedPAwavesweredetectedbya
custom-builtunfocused needle
ultrasonictransducer(centralfrequency
35MHz;bandwidth:50%;activeelementsize:
0.5x0.5mm2
).Theultrasonictransducerwas
gentlyattachedtotheeyelid(closetothe
canthus)coupledbyathinlayer ofmedical-
gradeultrasoundgel.

78. Infrared
Retinoscopy
2014
Infrared Retinoscopy
http://dx.doi.org/10.3390/photonics1040303
Retinoscopy could be a more effective and
versatile clinical tool in observing a wide range
of ocular conditions if modificationswere made
to overcome the inherent difficulties. In this
paper, a laboratory infrared retinoscope
prototype was constructed to capture the
digital images of the pupil reflex of various
typesofeyeconditions.
The capturedlow-contrastrefleximagesdueto
intraocular scattering were significantly
improved with a simple image processing
procedure for visualization. Detections of
ocular aberrations were demonstrated, and
computational models using patients’
wavefront data were built to simulate the
measurementfor comparison.
The simulation results suggest that the retinal
stray light that is strongly linked to intraocular
scattering extend the detection range of
illuminating eccentricity in retinoscopy and
make it more likely to observe ocular
aberrations.

79. Light Levels
Maximumintensities
limitedbywhatis
safeforhumaneye

80. ISO 15004-2.2
Standard for safe
retinalirradiancewith
ophthalmic instruments
Used e.g. by
Kölbl et al. (2015)
Sheng Chiong Hong (2015)
for discussion on limits, see
Sliney et al. (2005)
Wangetal.(2018)
https://doi.org/10.1038/s41598-018-27112-x
“According to the ISO 15007-2:2007 (Petteri:
Incorrect standard reference) standard, a
maximum of 10 J/cm2
weighted
irradiance is allowed on the retina without
photochemicalhazardconcern.”
Kim, Delori, Mukai (2012):
Smartphone Photography Safety
https://www.aaojournal.org/article/S0161-6420(12)00410-1/pdf
The light safety limits for ophthalmic instruments set by the International
Organization for Standardization (ISO 15004-2.2) recommend that spectral
irradiance (W/cm2
/nm) on the retina be weighted separately for thermal and
photochemical hazard functions or action spectra. These safety limits are at least 1
order of magnitude below actual retinal threshold damage [Delori et al.2007; Slineyet al.2002]
.
The radiant power of the smartphonewas8 mW.
For thermal hazard, the weighted retinal irradiance for the smartphone was 4.6
mW/cm2
, which is 150 times below the thermal limit (706 mW/cm2
). For
photochemical hazard, the weighted retinal radiant exposure was 41 mJ/cm2
(exposure duration of 1 minute), which is 240 times below the photochemical limit
(10 J/cm2
). Since the light safety standards not only account for the total retinal
irradiance but also for spectral distribution, we measured the latter with a
spectroradiometer (USB4000, Ocean Optics, Dunedin, FL). The radiation was
limited to the 400–700 nm wavelength interval with about 70% of that light emitted
inthe blue and green partof the spectrum (wavelength600nm).
We then compared the light levels produced during smartphone fundoscopy
with those produced by standard indirect ophthalmoscopes. The retinal
irradiance produced by a Keeler VantagePlusLED (Keeler Instruments Inc.,
Broomall, PA), measured using identical procedures as earlier described, was 46
mW/cm2
or about 10 times the levels observed with the smartphone. This
finding corresponds well with retinal irradiances of 8 to 210 mW/cm2
found in other
studies for a wide selection of indirect ophthalmoscopes. The spectral distribution
of the Keeler indirect ophthalmoscope was similar to that of the smartphone (both
have LED sources). The weighted exposures for the Keeler indirect
ophthalmoscope were thus 15 and 24 times less than the limits for thermal and
photochemical hazards, respectively. The lower light level available for
observation using the smartphone, as opposed to the indirect ophthalmoscope, is
largelycompensated for bythe high electronicsensitivityof the camera.
In conclusion, retinal exposure from the smartphone was 1 order of
magnitude less than that from the indirect ophthalmoscope and both are
within safety limits of thermal and photochemical hazards as defined by the ISO
whentested under conditions simulatingroutinefundoscopy.
Hazard weighting functions according to the
DIN EN ISO 15007 – 2: 2014 standard A(λ)
and R(λ). A(λ) rates the photochemical and
A(λ) rates the thermal hazard for all kinds of
lightsources.Kölbletal.(2015)

81. Example of
Calculation
For calculatingretinal
irradiance from quasi-
monochromatic green
(565nm)parsplanar
illumination
2018
Contact-free trans-pars-planar illumination enables snapshot
funduscamerafornonmydriatic wide field photography
https://doi.org/10.1038/s41598-018-27112-x
The thickness of the sclera is ~0.5 mm Olsenet al.1998
. The
transmission of the sclera in visible wavelength is 10–30%
Vogeletal.1991
.Tobeconservative,30%wasusedforcalculation.
For the proof-of-concept experiment, the weighted
irradiance on the sclera was calculated to be 0.5 mW, the
area of the arc-shaped light was 13 mm2
. For the worst case
estimation,we assumedallillumination lightdirectlyexposeto
the retinal area behind the illuminated sclera area. Therefore,
themaximumallowedexposuretimeis
If the illumination light accidently fell into the pupil, the
illuminated area on retina was estimated to be >9 mm2
. Thus
the maximum allowedexposuretimethrough thepupilis >30
minutes. For thermal hazard, the maximum weighted power
intensity allowed on the sclera without thermal hazard
concern is 700 mW/cm2
. The calculated weighted power
intensity was 230 mW/cm2
, which was more than three times
lower thanthemaximumlimit.
Kölbletal. (2015)
lightsourcearoundshapedwhiteLEDisused.Byintegrationof
thelight sourceintoa speculum, theLEDispressedfirmly held
against thesclera. Thustheocularspaceisilluminated
transsclerally.Asaresult anindirect uniformilluminationofthe
completeintraocularspaceisachieved.

82. Example of the
use of
Supercontinuum
light source
We assessed the spectral sensitivity of the
pupillary light reflex in mice usinga high
power supercontinuum white light
(SCWL) source in a dual wavelength
configuration. Thisnovel approachwas
comparedto data collected from a more
traditional setupusing a Xenon arclamp
fitted withmonochromatic interference
filters.
2018
Use ofa supercontinuum whitelight inevaluating thespectral
sensitivity of the pupillight reflex
CatherineChin; Lasse Leick; Adrian Podoleanu;GurpritS. Lal
Univ. ofKent(United Kingdom);NKTPhotonics A/S (Denmark)
https://doi.org/10.1117/12.2286064
Lightwasgenerated
bytheNKTPhotonics
SuperKExtremeEXR
andfilteredthrough
ExtendedUV(480
nm)andSuperK
Select (560nm)
modules.
The use of a SCWL is a significant leap
forward from the Xenon arc light
traditionally used in recording pupillary light
responses. The SCWL gives the
experimenter much more control over the
light stimulus, through wavelength, intensity
and, most importantly, a dual light
configuration.
Together, this will allow more complex
lighting protocols to be developed that
can further assist in unraveling the complex
coding of light that gives rise to the pupil light
reflex and other photic driven physiological
responses

83. Image
Processing
Introforcompensating
lowimagequality
computationally

84. Fundus Video
Processing
2014
Multi-frameSuper-resolutionwith
QualitySelf-assessmentforRetinal
FundusVideos
https://doi.org/10.1117/12.2036970
Thomas Köhler, Alexander Brost, Katja Mogalle, QianyiZhang, Christiane
Köhler, Georg Michelson, JoachimHornegger, RalfP. Tornow
In order to compensate heterogeneous illumination on the
fundus, we integrate retrospective illumination correction
for photometric registration to the underlying imaging
model. Our method utilizes quality self-assessment to
provide objective quality scores for reconstructed images
as well as to select regularization parameters
automatically. In our evaluation on real data acquired from
six human subjects with a low-cost video camera, the
proposed method achieved considerable enhancements
of low-resolution frames and improved noise and
sharpnesscharacteristicsby 74%.
2014
Bloodvesselsegmentationinvideo-
sequencesfromthehumanretina
https://doi.org/10.1109/IST.2014.6958459
J . Odstrcilik ; R. Kolar ; J. Jan ; R. P. Tornow ; A. Budai
This paper deals with the retinal blood vessel
segmentation in fundus video-sequences acquired by
experimental fundus video camera. Quality of acquired
video-sequences is relatively low and fluctuates across
particular frames. Especially, due to the low resolution,
poor signal-to-noise ratio, and varying illumination
conditions within the frames, application of standard
image processing methods might be difficult in such
experimental fundusimages.
2014
Geometry-BasedOpticDiskTrackingin
RetinalFundusVideos
https://doi.org/10.1007/978-3-642-54111-7_26
Anja Kürten, Thomas Köhler, Attila Budai, Ralf-Peter Tornow, Georg Michelson,
JoachimHornegger
Fundus video cameras enable the acquisition of image
sequences to analyze fast temporal changes on the
human retina in a non-invasive manner. In this work, we
propose a tracking-by-detection scheme for the optic disk
to capture the human eye motion on-line during
examination. Our approach exploits the elliptical shape of
the opticdisk.
2016
Registrationofretinalsequencesfrom
newvideo-ophthalmoscopiccamera
https://doi.org/10.1186/s12938-016-0191-0
RadimKolar, Ralf. P. Tornow, JanOdstrcilik and Ivana Liberdova
Analysis of fast temporal changes on retinas has become
an important part of diagnostic video-ophthalmology.
It enables investigation of the hemodynamic processes in
retinal tissue, e.g. blood-vessel diameter changes as a
result of blood-pressure variation, spontaneous venous
pulsation influenced by intracranial-intraocular pressure
difference, blood-volume changes as aresult of changesin
light reflection from retinal tissue, and blood flow using
laser speckle contrast imaging. For such applications,
image registration of the recorded sequence must be
performed.

85. Multiframe
registration
July2018
Fundusphotographywithsubpixel
registrationofcorrelatedlaserspeckle
images
https://doi.org/10.7567/JJAP.57.09SB01
Jie-EnLiandChung-HaoTien
Schematic diagram of the
optics of fundus
photography. LS, light source;
CL, collector lens; AD,
aperture diaphragm; BS,
beam splitter; FD, field
diaphragm; Ln, lenses. In our
experiment, the focal lengths
of the lenses are 30 and 100
mm (f1 = 300 mm and f2 =
100 mm).
Imagesofrabbitretinawith (a)
incoherent illumination, (b)
coherent illumination, and (c) LSCI
image. Vesselsenclosed bythered
frame are barely distinguishable in
imagesobtained usingaconventional
fundussystem, but are enhanced
when their imagesareobtained with
the help ofLSCI.
Imagesobtainedbylaser
specklecontrastimaging
(LSCI)(a)withoutimage
registrationand (b)with
imageregistration
process.(c)Speckle
contrastof(a)and(b)along
theredlines.

86. Future of
Fundus
Imaging
Hardware becoming a
low-cost commodity
with thevalue ofeasy
dataacquisition
increasing

87. Google
building a
2018
OpticalSystemsEngineer
VerilyLifeSciences
https://www.linkedin.com/jobs/view/674965920
Responsibilities
●
Designstate-of-the-artoptics-based
devices.
●
Work closelywithinterdisciplinaryteamto
integrateopticaldesignsinto
prototypes and productdevelopment
path.
MinimumQualifications
●
PhD in Optical Engineering/Optics/Physics/
EE, or related technical field or equivalent
practical experience.
●
Knowledgeand experiencein optical
design, optics and imaging systems design.
●
Applied research experience in
physics/optics/imagingsystems.
●
PreferredQualifications
●
Experience in opto-mechanicaldesign
●
Experience in electronics (PCB schematic
capture and layout, soldering, etc.)
●
Programming experience in MATLAB/C/C+
+/Python
●
Experience withmicrocontrollers
●
Excellent communicationand collaboration
skills.
2018
ElectricalEngineer,
OphthalmicDevices
VerilyLifeSciences
https://www.linkedin.com/jobs/view/692175458
Responsibilities
●
Working with cross-functional teams to
define electronic systems based on system-
level requirements and tradeoffs
●
Designelectronic systems forhighly
miniaturizedelectronicdevices,
especiallyatthe PC board level
●
Identification, selection and qualificationof
keyelectronic components for electronic
systems in miniaturized medical devices
●
Identification and qualification of key
vendorsandpartners for electronics
integration and manufacture
●
Rapidprototypingofelectronic
systems with in-houseteams and with
support from vendors, including integration
with avariety ofelectrical and mechanical
components
MinimumQualifications
●
MSdegreeinElectrical Engineering or
related major plus 4 years work experience
●
Solidanaloganddigitalcircuitdesign
skill
●
Experiencewithcomplex PC board design
●
Experiencewithfirmware development
2018
TechnicalLead,
OphthalmicDevicesand
ElectroactivePolymers
VerilyLifeSciences
https://www.linkedin.com/jobs/view/technical-lead
-ophthalmic-devices-and-electroactive-polymers-
at-verily-life-sciences-731643271/
Responsibilities
●
Leading thedevelopment ofnew
ophthalmologicaldevices and
diagnostic instrumentation.
●
Early-stagehardware and systems
development.
MinimumQualifications
●
Experiencein electroactivepolymer
applicationsinopticalsystems.
●
Experiencewith embedded systems
hardware/software development.
●
Experiencewith differentstages ofproduct
development:proof-of-concept, prototyping,
EV and DVbuilds.
PreferredQualifications
●
Experiencewith opto-mechanical
systems and components. Experience
withophthalmic devices.
●
Background in bothhardwareand
software. Programming experiencewith
C++ and Python.
●
Experiencein optics and electronics witha
focus on optical/spectral
imaging/sensingtechnologies.
●
Product development track record inoptical
applications of electroactivepolymers
or similar.
●
Experiencewith Camera, ImageSignal
Processor (ISP) orcamerasoftware
stack. Knowledge ofsignal processing,
digital imaging, computervision, and image/
video processing. ExperiencewithSoC,
cameramodules, VR/AR display
techniques.
●
Experiencewith (real time)data processing
LilyPeng–Google Brain
Talkingabout deeplearningforfundus
images(diabeticretinopathy),andtheir
collaborationwith ArvindinstituteinIndiaat
APTOS2018

88. Portable
adaptive optics
for improving
image quality
05Sep2018
Adaptiveopticsrevealsfinedetailsof
retinalstructureDukeUniversityhandheldAOSLO
platform assistsdiagnosisofeyediseaseandtrauma
http://optics.org/news/9/9/5
"To overcome the weight and size restrictions in
integrating AOSLO into handheld form (weighing
less than 200g), we used recent advancements in
the miniaturization of deformable mirror
technology and 2D microelectromechanical
systems (MEMS) scanning, together with a novel
wavefront sensorless AO algorithm and a custom
optical and mechanical design," commented the
teamintheOpticapaper.
The newprobe andassociatednumericalmethods
could be useful for a variety of applications in
ophthalmic imaging, and the Duke team has made
its designs and computational algorithms available
as opensourcedata for otherresearchers.
The system was able to image photoreceptors as
close as 1.4 degrees eccentric to the fovea area
of the retina, where photoreceptors have an
average spacing of 4.5 microns. Without AO, the
closest measurement had previously been 3.9
degrees. Further clinical trials with the instrument
will follow, and the researchers plan to incorporate
additional imaging modalities into the
platform that could prove useful for detecting
otherdiseases.
2018
Handheldadaptiveopticsscanning
laserophthalmoscope
https://doi.org/10.1364/OPTICA.5.001027
http://people.duke.edu/~sf59/HAOSLO.htm
Theodore DuBose, Derek Nankivil, FrancescoLaRocca, GarWaterman,
Kristen Hagan, James Polans, BrentonKeller, DuTran-Viet, Lejla Vajzovic,
Anthony N. Kuo, Cynthia A. Toth, Joseph A. Izatt, and SinaFarsiu

89. Novel
Components
For Imaging
The use of MEMStech,has already
allowed miniaturization of many
devices probing visualfunction
What more?

90. Diffractive
Optics for
Fundus
Imaging?
February2018
Broadbandimagingwithoneplanar
diffractivelens
https://doi.org/10.1080/24699322.2017.1379143
NabilMohammad,MonjurulMeem,Bing Shen,Peng Wang &Rajesh
Menon |Department of Electrical and Computer Engineering, MACOM Technology
Solutions, Department of Medical Engineering, CaliforniaInstitute ofTechnology
Here, we design, fabricate and characterize
broadband diffractive optics as planar lenses
for imaging. Broadband operation is achieved by
optimizing the phase transmission function for each
wavelength carefully to achieve the desired intensity
distribution at that wavelength in the focal plane. Our
approach is able to maintain the quality of the
images comparable to that achievable with
morecomplexsystemsoflenses.
The achromatic lenses were patterned on a
photoresist film atop a glass wafer using grayscale
laser patterning using a Heidelberg Instruments
MicroPG101 tool. The exposure dose was varied as a
function of position in order to achieve the multiple
heightlevelsdictatedbythedesign.
We show here that planar diffractive lenses, when
designedproperly and fabricated carefullyaresufficient
for broadband imaging. By extending the fabrication
process to industry-relevant lithographic scales and
large area replication via nanoimprinting (Guo2004), it
is possible to envision planar lenses enabling imaging
with very thin form factors, low weights and low costs.
Therefore, we believe that our approach will lead to
considerably simpler, thinner and cheaper imaging
systems.
(a) Schematic of a flat-lens design. The structure is
comprised of concentric rings of width, Wmin
and varying
heights. (b) Photograph of one fabricated lens. Optical
micrographs of (c) NA = 0.05 and (d) NA = 0.18 lenses.
Focal length is 1 mm. Measured full-width at half-maximum
(FWHM) of the focal spot as a function of wavelength for
(e) NA = 0.05 and (f) NA = 0.18 lenses. Measured focal
spots as a function of wavelength for (g) NA = 0.05 and (h)
NA = 0.18lenses.

91. Diffractive
Optics in intraocular
lenses (IOL) and satellite-
based remote sensing
July2018
Fractal-structuredmultifocal intraocularlens
https://doi.org/10.1371/journal.pone.0200197
LauraRemón, Salvador García-Delpech, Patricia Udaondo, VicenteFerrando, Juan
A. Monsoriu, WalterD. Furlan | Departamento de ÓpticayOptometríayCienciasdelaVisión,
UniversitatdeValència, Burjassot,Spain
In this work, we present a new concept of IOL design inspired by the
demonstrated properties of reduced chromatic aberration and
extended depth of focus of Fractal zone plates. A detailed
description of a proof of concept IOL is provided. The result was
numerically characterized, and fabricated by lathe turning. The
prototype was tested in vitro using dedicated optical system and
software. The theoretical Point Spread Function along the optical axis,
computed for several wavelengths, showed that for each wavelength,
the IOL produces two main foci surrounded by numerous secondary
foci that partially overlap each other for different wavelengths. The result
is that both, the near focus and the far focus, have an extended
depth offocusunderpolychromaticillumination.
May2018
ModificationofFresnelzonelightfield
spectralimagingsystemforhigher
resolution
https://doi-org/10.1117/12.2303898
CarlosDiaz; Anthony L.Franz;Jack A.Shepherd
Air Force Institute ofTechnology (United States)
Recent interest in building an imaging system using
diffractive optics that can fit on a CubeSat (10 cm x 10
cm x 30 cm) and can correct severe chromatic
aberrations inherent to diffractive optics has led to the
development of the Fresnel zone light field
spectral imaging system (FZLFSI). The FZLFSI is a
system that integrates an axial dispersion binary
diffractive optic with a light field (plenoptic)
camera design that enables snapshot spectral
imaging capability.

92. Metamaterial
Optics for
Fundus
Imaging?
July2017
Metamaterialsandimaging
https://dx.doi.org/10.1186/s40580-015-0053-7
MinkyungKimandJunsuk Rho
Here, we review metamaterial-based lenses which
offer the new types of imaging components and
functions. Perfect lens, superlenses, hyperlenses,
metalenses, flat lenses based on metasurfaces, and
non-optical lenses including acoustic hyperlens are
described.
Not all of them offer sub-diffraction imaging, but they
provide new imaging mechanisms by controlling
and manipulating the path of light. The underlying
physics, design principles, recent advances, major
limitations and challenges for the practical
applicationsarediscussedinthisreview.
Diffraction-free acoustic imaging using metamaterials
allows more efficient underwater sonar sensing,
medical ultra-sound imaging, and non-
destructivematerialstesting.
Therefore, with the development of
nanofabrication and nanomanufacturing
methods, and the integration of new creative ideas,
overcoming the results and limitations mentioned in
this review will be the continuous efforts to make
metamaterial-based imaging techniques to be a next
generation of imaging technology replacing current
optical microscopy, which thus can be called
nanoscopy.
2018
Dynamicallytunableandactivehyperbolic
metamaterials
https://doi.org/10.1364/AOP.10.000354
Joseph S.T.Smalley,FelipeVallini, XiangZhang, andYeshaiahu
Fainman
Here

93. Metasurface
Optics for
Fundus
Imaging?
July2017
OpticswithMetasurfaces:Beyond
RefractiveandDiffractiveOptics
https://doi.org/10.1364/OFT.2017.OW1B.5
MohammadrezaKhorasaninejad
HarvardUniversity
Flat optics based-on metasurfaces has
the potential to replace/complement
conventional refractive/diffractive
components. In this talk, we give an
overview of our works on dielectric-
metasurfaces, which have led to high
performance components in the visible
spectrum.
https://doi.org/10.1364/OPTICA.4.000139
Nano-opticendoscope seesdeep intotissueathigh resolutionNow, experts in
endoscopic imagingat Massachusetts General Hospital (MGH) and pioneers of flatmetalens technologyatthe
HarvardJohn A. Paulson School ofEngineering and Applied Sciences (SEAS), haveteamed up to develop a
new class ofendoscopic imaging catheters –termed nano-optic endoscopes
-https://doi.org/10.1038/s41566-018-0224-2
Departmentof ElectricalandComputer Engineering,NationalUniversityof Singapore,
Singapore,Singapore- Yao-Wei Huang &Cheng-Wei Qiu