This document discusses using optical coherence tomography (OCT) to analyze the macula, retinal nerve fiber layer (RNFL), and optic nerve head in patients with glaucoma or suspected glaucoma. It describes how OCT can measure macular thickness, RNFL thickness, and optic disc parameters. Five case studies are presented showing how structural changes seen on OCT correlate with functional defects on visual field tests or clinical findings. The document concludes by mentioning Doppler OCT may help understand the role of blood flow in glaucoma and other optic neuropathies.

1. Dr. Jagdish Dukre
Senior Resident,
Regional Institute Of Ophthalmology, Allahabad

2. Peri papilary
Nerve fiber layer
Macular thickness
Optic nerve
head

3. OCT Software analyses-
Macula Thickness
Retinal Nerve Fibre Layer (RNFL)
Optic Nerve Head (ONH)

4. Macula Thickness Analysis
Ganglion cells- 30-35% of total retinal thickness at macula
upto 50%of ganglion cells in macula
glaucoma preferentially involves the ganglion cell complex (GCC).
Normal
Glaucoma with thinner GCC

6. RNFL analysis
 Circular scanning
around ONH at a radius
of 1. 73mm
 Three scans are acquired
and data is averaged and
compared with
normative data base of
age matched subjects
 Scan begins temporally

7. RNFL thickness average analysis printout -7
zones
 Zone -1-Pt. I.D
 Zone -2-TSNIT with age matched normative data base
 Zone-3-TSNIT overlap of two eyes
 Zone -4-circular scan-quadrant/clockwise
 Zone-5-DATA TABLE-ratio/average
 Zone-6-RED FREE PHOTOGRAPH-position
 Zone-7-PERCENTILE COLOR CODING

8. 7
6
5
4
3
2
1

9. Optic nerve head analysis
Optic nerve head scans are
composed of six linear
scans in a spoke pattern
separated by 30-degree
intervals centered on the
ONH

10. Cup/disk ratios and cup Volumes
Disc size:
 by measuring the distance
between the terminal ends of
the choriod at the level of the
pigment epithelium (green
line)
Cup:
 determined by drawing a line
b/w both sides of the cup at a
point 140um above the green
line.
 Area below the line is cup and
above is neuroretinal rim

12. Case 1-(Structure Function Correlation)
 56 year old female with open angle glaucoma
 NFL lesion at inferior pole of ONH
 Superior defect in perimetry
 Thinning of RNFL in OCT

16. Case 2 (early glaucoma)
 59 year old male with suspicious optic nerve
 Normal perimetry
 Normal IOP
 No positive family history
 Thinning of NRR clinically
 Nasal step in SWAP
 RNFL thinning in OCT

23. Case 3-(Unilateral Open Angle Glaucoma)
 54 year old female
 Unilateral exfoliative glaucoma
 IOP- 33 mmHg
 Thinning of NRR in sup, inf and temporal
 Inferior arcuate defect in perimetry
 RNFL thinning in sup and inf pole in OCT

27. Case 4-Glaucoma suspect
 62 year old female
 Large C:D ratio
 B/L with positive family history
 Normal IOP
 Normal achromatic and FDP
 Normal RNFL and large disc area and increased C:D
ratio on OCT

32. Case 5 (Ocular Hypertension)
 Suspicious optic nerve head
 Perimetry normal
 Borderline FDP
 Borderline thickness values with more thinning at
superior and inferior pole on OCT

38. DOPPLER OCT(F-Domain)
Retinal blood flow measurement with Doppler OCT may help
us understand the role of perfusion in the causation and treatment
of glaucoma, other optic neuropathies and retinal diseases