Akira Arakawa

In Brief Purpose: To evaluate the macular structure on spectral-domain optical coherence tomographic (SD-OCT) images to predict the outcome of surgery for idiopathic epiretinal membrane. Methods: Forty-five eyes of 45 consecutive patients with idiopathic epiretinal membrane who had a preoperative visual acuity of ≤20/32 and were scheduled to undergo a transconjunctival 25-gauge vitrectomy were involved in this prospective cohort study. The best-corrected visual acuity (BCVA) and SD-OCT images of the fovea were examined before the surgery and at 3, 6, and 12 months after the surgery. Associations between the visual acuity parameters and the preoperative SD-OCT features, including the morphology of the photoreceptor inner segment/outer segment junction, macular thickness, presence/absence of retinal cysts, and presence/absence of a macular pseudohole, were investigated as predictors of the outcome of the surgery. The main outcome measures were the association between the macular microstructure on preoperative SD-OCT images and the visual acuity parameters, such as the BCVA, at 12 months after the surgery (postoperative BCVA) and the difference between the preoperative visual acuity and the postoperative BCVA. Results: A total of 45 patients were enrolled in this study. The postoperative visual acuity was significantly better for the eyes with an intact inner segment/outer segment junction on the preoperative SD-OCT images than for those with an irregular or a disrupted inner segment/outer segment junction on the images (P < 0.001). Better preoperative visual acuity was associated with better visual acuity at 12 months and a lesser degree of improvement in the visual acuity (P < 0.001, respectively). Conclusion: The presence of an intact inner segment/outer segment junction on the preoperative SD-OCT images was found to be an important predictor of better visual recovery and better postoperative BCVA after epiretinal membrane surgery. Spectral-domain optical coherence tomography enabled clear visualization of the macular microstructure in patients with epiretinal membrane. An intact inner segment/outer segment junction on preoperative spectral-domain optical coherence tomography was found to be an important prognostic factor for better visual recovery and postoperative best-corrected visual acuity after epiretinal membrane surgery.