IERG Abstracrt Book.indd - LV Prasad Eye Institute

IPT 042Oral Presentation57Comparitive Evaluation of Time Domain and Spectral Domain Optical CoherenceTomography in Retinal Nerve Fiber Layer Thickness MeasurementsAmit Sobti, Shibal Bhartiya, Mahesh HM Kumar, Ajay Sharma, Sunil K. Mishra, Tanuj DadaDr R P Centre for Ophthalmic Sciences, AIIMS, New Delhi, India.Purpose: To perform a comparative evaluation of retinal nerve fiber layer (RNFL) measurementsbetween two optical coherence tomography (OCT) systems: the Stratus OCT, a time domainsystem, and the Cirrus HD-OCT, a spectral domain system (both by Carl Zeiss Meditec, Inc.,Dublin, CA) in the Indian patients.Methods: 116 eyes of 116 subjects (60 eyes with primary open angle glaucoma and 56 eyesof healthy controls) were enrolled for this observational cross-sectional study. Reliability wasassessed by the Intra-class correlation coefficient (ICC) and the Bland Altman plot for thelimits of agreement for the overall mean RNFL thickness and for each quadrant.Results: The mean age of patients was 48.53 ± 6.62 yrs. (24-68 yrs). Mean RNFLthickness (microns) was noted as (Stratus/Cirrhus OCT) – temporal- 58.30+17.18/56.38± 12.51(ICC=0.82), superior- 97.78 ± 29.02/97.73 ±31.16 (ICC=0.87), inferior- 99.95 ±34.45/103.78 ± 32.03 (ICC=0.98), nasal- 64.28 ± 23.87/63.27 ± 21.33 (ICC=0.85), average-80.84 ± 21.10/80.52 ± 19.24 (ICC=0.92) in glaucoma patients and an average value of 96.94 ±13.87/93.90 ± 12.99 (ICC=0.71) in the healthy controls. Bland-Altman plots showed the limitsof agreement (95%CI) for average RNFL to be -28.37 to 22.31 microns in the control group. Inpatients of glaucoma, Bland-Altman plots showed the limits of agreement (95%CI) for averageRNFL to be 21.45 to -22.07 microns.Conclusions: The two OCT systems show excellent correlation in measurement of RNFLthickness in glaucoma patients and normal patients.