Fixation and photoreceptor integrity in optical coherence tomography

Purpose: To investigate eccentric fixation (EF) in full-thickness macular hole (FTMH) and epiretinal membrane (ERM) and its relationship to photoreceptor integrity. Methods: The amount of EF during spectral domain optical coherence tomography scanning was determined as the distance between the scan center and the foveal center. We investigated the difference in reflectivity of the photoreceptor inner segment/outer segment (IS/OS) junction at the scan center and the foveal center. Results: The amount of EF was significantly greater in preoperative FTMH (median, 209 μm; interquartile range [IQR], 146 μm, 367 μm), postoperative FTMH (median, 138 μm; IQR, 95 μm, 461 μm), preoperative ERM (median, 210 μm; IQR, 151 μm, 308 μm), and after removal of ERM (median, 129 μm; IQR, 72 μm, 175 μm) than normal eyes (median, 67 μm; IQR, 47 μm, 101 μm). Abnormal EF was more frequently observed in eyes with greater inner segment/outer segment reflectivity at the scan center than at the foveal center. Conclusions: Fixation during the spectral domain optical coherence tomography scanning was frequently eccentric in FTMH and ERM and might be dependent on photoreceptor integrity.