Reproducibility of retinal thickness measurements in patients with age-related macular degeneration using 3D Fourier-domain optical coherence tomography (OCT) (Topcon 3D-OCT 1000)

Abstract

Purpose:  Conventional time-domain optical coherence tomography (OCT) has become an important tool for following dry or exudative age-related macular degeneration (AMD). Fourier-domain three-dimensional (3D) OCT was recently introduced. This study tested the reproducibility of 3D-OCT retinal thickness measurements in patients with dry and exudative AMD.

Methods:  Ten eyes with dry AMD and 12 eyes with exudative AMD were included in the study. Sets of three OCT 6 × 6-mm raster scans were taken by one operator. Mean retinal thickness was calculated for 36 areas. Coefficients of variation (CoV) were calculated for each patient and area. For analysis, two separate areas (central and peripheral) were defined. Generalized estimating equations (GEEs) were applied to all 36 subfields in order to analyse possible differences in CoV and mean retinal thickness between dry and exudative AMD.

Results:  Mean retinal thickness values were significantly larger in the central area in exudative AMD (p < 0.001). Mean CoV for exudative AMD was 3.7% (standard deviation [SD] 1.4%). Mean CoV for dry AMD was 1.8 (SD 0.6%). The reproducibility of retinal thickness measurements was significantly less in exudative AMD (p = 0.009).

Conclusions:  Reproducibility of 3D-OCT retinal thickness measurements was good in both groups. However, reproducibility was significantly better in dry AMD than in exudative AMD.