High-Resolution Imaging of the Photoreceptor Layer in Epiretinal Membrane Using Adaptive Optics Scanning Laser Ophthalmoscopy

Objective To compare, in eyes with an idiopathic epiretinal membrane (ERM), photoreceptor cell structural abnormalities identified on high-resolution images obtained by adaptive optics scanning laser ophthalmoscopy (AO-SLO) with the severity of metamorphopsia and anatomic findings on spectral-domain optical coherence tomography (SD-OCT). Design Observational case series. Participants Twenty-five eyes of 24 patients with idiopathic ERM and 20 normal eyes of 20 volunteer subjects. Methods All participants underwent a full ophthalmologic examination, SD-OCT, and imaging with an original prototype AO-SLO system that incorporated liquid crystal-on-silicon technology. In eyes with ERM, M-CHARTS results were used to quantify metamorphopsia. Main Outcome Measures Cone mosaic patterns on AO-SLO images and metamorphopsia severity. Results In normal eyes, AO-SLO images showed a regular photoreceptor mosaic pattern. In 24 (96%) of 25 eyes with ERM, “microfolds” (multiple thin, straight, hyporeflective lines in the photoreceptor layer) were identified on AO-SLO images; microfolds were not seen in normal eyes. Individual microfolds were approximately 5 to 20 μm wide, which is narrower than retinal folds seen in fundus photographs (>50 μm). Amsler charts revealed metamorphopsia around the fixation point in 12 of 13 eyes with microfolds in the fovea on AO-SLO but in none of 5 eyes without microfolds in the fovea ( P