Decreased photoreceptor inner segment/outer segment junction reflectivity in patients with idiopathic epimacular membrane

Purpose To assess the effects of idiopathic epimacular membrane (IEMM) on retinal pigment epithelium (RPE), photoreceptor inner segment/outer segment (IS/OS) junction, and external limiting membrane (ELM) reflectivities to determine functional alterations in these layers using optical coherence tomography (OCT) image analysis. Methods Fifty eyes of 50 patients with untreated IEMM and 41 eyes of 41 age- and sex-matched healthy controls with normal OCT scans were retrospectively reviewed. A single masked physician analyzed OCT images randomly. Reflectivity values of RPE, IS/OS junction, and ELM were obtained using 'plot profile' mode of a medical image processing computer software. Results The study comprised 50 patients with untreated IEMM and age- and sex-matched 41 control subjects (P>0.05). Image analysis demonstrated that IS/OS junction and ELM had significantly lower reflectivity in patients with IEMM compared with those of the control eyes (P = 0.008, P = 0.009, respectively). However, RPE reflectivity did not differ between two groups (P = 0.100). Correlation analyses showed no significant associations between reflectivity values and corrected visual acuity (P>0.05). Conclusion In patients with IEMM, photoreceptor IS/OS junction and ELM seem to have lower reflectivity, which might indicate impaired functionality even though these layers are not apparently damaged on OCT imaging.