Abstract
Abstract: :
Purpose:To compare the performance of the "Fast RNFL Thickness" and the "Fast Optic Disc" algorithms of the Stratus OCT for detection of early perimetric glaucoma. Methods: One eye from 34 normal controls and 63 open–angle glaucoma patients with visual acuity equal to or better than 20/40, aged 30 years or older, and no other ocular pathology were selected. Glaucoma was described as presence of a visual field defect on automated perimetry based on predefined criteria. Two different OCT algorithms, the Fast RNFL Thickness and the Fast Optic Disc (FOD), were performed on all study eyes. The discriminating ability of the average RNFL thickness and RNFL thickness in sectors and quadrants was compared to 8 optic disc parameters derived from the FOD algorithm. ROC curves, senstivities, and specificities were used to compare the performance of the two approaches. Results: The average MD (±SD) was –0.8 (± 2.8) and –3.9 (± 3.9) dB in the control and glaucoma groups, respectively. Average RNFL thickness was 93.7 ± 13.6 and 73.8 ± 12.7 microns (p < 0.001) in the normal and glaucomatous eyes with an area under the curve (AUC ± SE) of 0.856 ± 0.04. RNFL thickness in the inferior quadrant and in the 6 o’clock sector had the highest AUC for detection of glaucoma (0.902 ± 0.03 and 0.861 ± 0.04). Among FOD parameters, Horizontal Integrated Rim Width (HIRW) had the highest AUC (0.912 ± 0.03 SE with the automated algorithm and 0.920 ± 0.03 SE with the manual correction). There was no statistically significant difference between AUC of the inferior quadrant or the 6 o’clock sector RNFL thickness and HIRW (p > 0.05 for both). With specificity fixed at 90%, sensitivity (95% CI) of the RNFL thickness in the inferior quadrant, and the manually corrected HIRW were 79% (71–87%) and 78% (70–86%), respectively. Conclusions: The Fast Optic Disc algorithm of OCT performs as well as the Fast RNFL Thickness algorithm for discrimination of early glaucomatous from normal eyes. However, the sensitivity of both algorithms is only fair when specificity is set at a high level.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer • optic disc