oct in glaucoma
DESCRIPTION
Oct in glaucomaTRANSCRIPT
Dr. Jagdish Dukre
Senior Resident,
Regional Institute Of Ophthalmology, Allahabad
Peri papilaryNerve fiber layer
Macular thickness
Optic nerve head
OCT Software analyses-
Macula Thickness
Retinal Nerve Fibre Layer (RNFL)
Optic Nerve Head (ONH)
Ganglion cells- 30-35% of total retinal thickness at macula upto 50%of ganglion cells in maculaglaucoma preferentially involves the ganglion cell complex (GCC).
Macula Thickness Analysis
Glaucoma with thinner GCC
Normal
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
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
7
6
5
4
3
2
1
Optic nerve head analysisOptic nerve head scans are
composed of six linear scans in a spoke pattern separated by 30-degree intervals centered on the ONH
Cup/disk ratios and cup VolumesDisc 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
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
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
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
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
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
DOPPLER OCT(F-Domain)
Retinal blood flow measurement with Doppler OCT may helpus understand the role of perfusion in the causation and treatmentof glaucoma, other optic neuropathies and retinal diseases