Purpose:
The purpose of this study was to determine the association between the extent of photoreceptor defects as measured by Spectral Domain optical coherence tomography (SD-OCT) and vision loss in patients with exudative AMD.
Methods:
Fifteen patients with exudative AMD were enrolled in the study. All patients underwent fluorescein angiography and SD-OCT (Cirrus HD-OCT, Carl Zeiss Meditec Inc). Central retinal thickness was measured using the 512 x 128 Macular Cube Scan. Visualization of choroidal neovascularization (CNV) and the measurements of the topographical extent of photoreceptor inner/outer segment (IS/OS) junction defects in the macular region were performed using the HD 5-line raster scan. The measurement of the photoreceptor defects was performed from the horizontal scan through the foveal center using the caliper function of the OCT software.
Results:
Visualization of CNV and photoreceptor defects in the macula were observed on SD-OCT images of all 15 patients. The extent of photoreceptor defects in the macular region revealed in diameter ranged from 448 to 4520 µm (mean 1898 µm). Central retinal thickness ranged from 226 to 440 µm (mean 331 µm). The extent of photoreceptor defects showed a significant inverse correlation with the best corrected visual acuity (BCVA) (Rsq=0.62, P<0.001). There was no significant correlation between the foveal thickness and BCVA. The correlation between the photoreceptor defects in the macular region and central retinal thickness was also not significant.
Conclusions:
Our data show a significant correlation between the extent of photoreceptor defects in the macular region and vision loss, independently of retinal thickness in patients with exudative macular degeneration. These results indicate that SD-OCT can be used for accurate determination of photoreceptor layer integrity, offering a prognostic value for visual function in patients with exudative AMD.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors