Inner segment/outer segment junction assessed by spectral-domain optical coherence tomography in patients with idiopathic epiretinal membrane

Purpose: To evaluate the anatomic features of the photoreceptor inner/outer segment (IS/OS) junction before and after surgery by spectral-domain optical coherence tomography in patients undergoing idiopathic epiretinal membrane (ERM) surgery and to correlate these features with the functional outcomes.

Design: Prospective, cohort study.

Methods: We prospectively studied 45 eyes of 45 patients with idiopathic epiretinal membrane who had a preoperative visual acuity of 20/32 or less and were scheduled to undergo transconjunctival 25-gauge vitrectomy. The patients were divided into 2 groups based on the preoperative structural integrity of the IS/OS junction: the intact IS/OS junction group and the disrupted IS/OS junction group. Changes in the IS/OS junction and best-corrected visual acuity were compared between 2 groups before and at 3, 6, and 12 months after surgery.

Results: A total of 45 patients were recruited for this study. There were 34 eyes with an intact IS/OS junction (group 1) and 11 eyes with a disrupted or irregular IS/OS junction (group 2), as determined before surgery. Significantly better postoperative best-corrected visual acuity was seen in group 1 as compared with that in group 2 at 3, 6, and 12 months after the surgery (P < .001). Significant improvement of visual acuity was also seen in group 1 when compared to group 2 (P < .05). Of the 34 eyes in group 1, 17 (50%) showed disruption of the IS/OS junction at 3 months after surgery, although this disruption was only transient and resolved completely by 12 months after the surgery. However, none of the eyes from group 2 showed a normal appearance of the IS/OS junction at any time point during the study period of 1 year.

Conclusions: The IS/OS junction can recover in eyes with preoperative intact IS/OS junction as assessed over a follow-up period of 1 year after surgery. Preoperative integrity of the IS/OS junction may be an important prognostic factor for better visual recovery and better improvement of the postoperative best-corrected visual acuity after epiretinal membrane surgery.