En Face Spectral-Domain Optical Coherence Tomography Outer Retinal Analysis and Relation to Visual Acuity

PURPOSE: To describe a method of en face visualization and quantification of the photoreceptor inner segment/outer segment junction area, using spectral-domain optical coherence tomography, and association with visual acuity. METHODS: Case series of 74 eyes in 53 patients. Central 1-mm and 400-μm en face areas were analyzed with a computer algorithm. RESULTS: The presence or absence of inner segment/outer segment junction was visible on both spectral-domain optical coherence tomography en face and retinal cross sections. Thirty eyes (40.6%) had no retinal pathology and an average logMAR visual acuity of 0.116. Twenty-five eyes (33.8%) had intraretinal edema, with visual acuity of 0.494. Nineteen eyes had nonneovascular age-related macular degeneration (dry age-related macular degeneration, 25.6%), with visual acuity of 0.392. In all eyes, central 1-mm and 400-μm en face areas were 58.3 ± 25.0% and 56.4 ± 26.0%, which showed significant correlation with visual acuity (Pearson correlation, r = -0.66 and -0.56, both P < 0.001). This correlation was greater than correlation of visual acuity with central subfield thickness (r = 0.39, P < 0.001), macular volume (r = 0.36, P = 0.002), and average macular thickness (r = 0.37, P = 0.001). However, no variables were significantly correlated with dry age-related macular degeneration eyes. CONCLUSION: Central en face inner segment/outer segment junction areas are significantly correlated with visual acuity in most eyes. This may correlate better with visual acuity than other spectral-domain optical coherence tomography values, as a reflection of photoreceptor integrity. Dry age-related macular degeneration may disrupt the plane used to formulate the en face display. Advancements in spectral-domain optical coherence tomography may provide routine en face visualization analysis.