Predicting the progression of geographic atrophy in age-related macular degeneration with SD-OCT en face imaging of the outer retina.

BACKGROUND AND OBJECTIVE Spectral-domain optical coherence tomography (SD-OCT) en face imaging was used to measure the growth of geographic atrophy (GA) and identify baseline anatomic changes in the outer retina in eyes with nonexudative age-related macular degeneration (AMD). PATIENTS AND METHODS In this prospective study, eyes were imaged using 200 × 200 and 512 × 128 A-scan raster patterns. Outer retinal anatomy was visualized using en face imaging of a 20-μm thick slab encompassing the inner segment/outer segment (IS/OS) band. RESULTS En face SD-OCT imaging of the IS/OS region revealed a bilaterally symmetrical pattern of outer retinal disruption extending beyond the borders of GA that accurately predicted the progression of GA over 1 year in 13 of 30 eyes (43.3%). In the remaining cases, the area of disruption was much larger than the area of progression. CONCLUSION En face imaging of the outer retina can predict the growth of GA in some eyes. Due to the bilateral symmetry of these findings, this imaging strategy may identify a genetic subset of patients in whom photoreceptor loss precedes the progression of GA. These areas with outer retinal disruption should be followed in clinical trials designed to test treatments for dry AMD.