Long-term outcome of preoperative disrupted inner/outer segment junctions assessed using spectral-domain optical coherence tomography in patients with idiopathic epiretinal membrane

Abstract

Purpose: To evaluate the anatomic and functional outcomes as assessed by spectral-domain optical coherence tomography in patients with a preoperative disrupted or irregular photoreceptor inner/outer segment (IS/OS) junction who underwent idiopathic epiretinal membrane (ERM) surgery and were followed for at least 2 years.

Methods: We retrospectively studied all of the patients with idiopathic ERM who had a preoperative disrupted IS/OS junction and were scheduled to undergo a transconjunctival 25-gauge vitrectomy between September 2007 and October 2009. All of the patients who had a 2-year or longer follow-up period were included in the study. The best-corrected visual acuity (BCVA) and structural changes in the IS/OS junction were examined before and 3, 6, 12, and 24 months after surgery. Furthermore, patients were divided into two groups based on whether the preoperative disrupted IS/OS junction had been caused by a lamellar macular hole (LMH type) or swelling as a result of ERM traction (S type). Morphologic changes in the IS/OS junctions of each type were also investigated.

Results: A total of 17 patients were identified in this study. Overall, a significantly better postoperative BCVA was seen after surgery; in particular, the BCVA at 24 months was significantly better than that at 12 months (p=0.018). Although the disrupted IS/OS junction appeared normal in 1 out of 17 eyes at 12 months, 7 eyes appeared normal at 24 months. These 7 eyes showed significant postoperative improvement in BCVA compared with the remaining 10 eyes (p=0.045, p=0.021, p=0.019, and p=0.015 at 3, 6, 12, and 24 months, respectively). The preoperative disrupted IS/OS junction was classified as LMH type in 8 eyes and as S type in 9 eyes. The LMH type, rather than the S type, tended to show a persistently disrupted IS/OS junction at 24 months, although the difference was not significant.

Conclusion: Anatomic and functional recovery of preoperative disrupted IS/OS junctions can be acquired even after more than 1 year postoperatively. However, eyes with persistent irregularities of the IS/OS junction at a 2-year follow-up, especially those with LMH type irregularities, might have a limited visual improvement.