Abstract
Purpose: :
To compare the ability of time-domain optical coherence tomography (OCT) for detecting diffuse and localized retinal nerve fiber layer (RNFL) defects using integral normative database in patients with early to moderate open angle glaucoma
Methods: :
This cross-sectional institutional study included 43 eyes of 43 subjects with diffuse RNFL defects and 89 eyes of 89 subjects with localized RNFL defects, both having localized visual field defects confined to one hemifield. Among 89 eyes with localized RNFL defects, 43 eyes of which mean deviation (MD) matched to that of 43 eyes with diffuse RNFL defects were selected for statistical analysis. The fast RNFL thickness protocol of the Stratus OCT (Carl Zeiss Meditec, Dubin, CA, USA) was used. The clock-hour sector and quadrant parameters corresponding to the hemifield with visual field defect were evaluated at P < 0.05 with regard to the integral normative database of Stratus OCT. The sensitivities of these parameters were compared between diffuse and localized RNFL defects.
Results: :
The average MD of glaucomatous eyes with diffuse RNFL defects (-2.63 ± 1.92 dB) was not significantly different compared with those with localized RNFL defects (-2.55 ± 2.05 dB) (P = 0.86). The sensitivity of clock-hour sector parameter in diffuse RNFL defects (83.7 %) was not significantly different compared with that in localized RNFL defects (81.4 %) (P = 1.00). The sensitivity of quadrant parameter in diffuse RNFL defects (74.4 %) was significantly higher than in localized RNFL defects (51.2 %) (P = 0.04).
Conclusions: :
The clock-hour parameter of time-domain OCT detected RNFL defects without significant difference of sensitivities between diffuse and localized pattern of RNFL loss in glaucomatous eyes. However, the quadrant parameter of Stratus OCT showed better sensitivity in diffuse defect than in localized RNFL defects.
Keywords: imaging/image analysis: clinical • nerve fiber layer