Perioperative intraretinal fluid observed using optical coherence tomography in the epiretinal membrane

BACKGROUND: Postoperative intraretinal fluid (IRF) is reportedly associated with visual outcomes after epiretinal membrane (ERM) surgery. However, preoperative IRF is common, and persistent IRF would have different impact on visual function from postoperative newly developed IRF. Therefore, we aimed to investigate the incidence rate and clinical implications of perioperative IRF in ERM. METHODS: Medical records of patients who underwent vitrectomy for idiopathic ERM between January 2014 and January 2017 were reviewed retrospectively. The incidence of IRF was analyzed using optical coherence tomography preoperatively and 1, 3, and 6 months postoperatively. On the basis of the presence or absence and the time of detection of IRF, patients were divided into three groups, namely preoperative IRF group, New IRF group, and IRF(−) group. Correlations of various parameters including age, sex, baseline visual acuity (VA), central subfield macular thickness, lens status, and surgical factors with IRF, along with the effect of IRF on VA, were evaluated. RESULTS: This study included 155 eyes from 155 patients. Thirty-six (23.2%) and 49 (31.6%) eyes demonstrated preoperative and newly developed IRF, respectively. Seventy eyes (45.2%), which did not exhibit IRF during the study period, were assigned to the IRF(−) group. At baseline, the IRF(−) group showed a better VA than the other two groups. Postoperatively, VA improved significantly in all three groups. There was no difference in VA between the IRF(−) and new IRF groups at 6 months; however, the preoperative IRF group had significantly lower VA than the other two groups. CONCLUSION: IRF associated with ERM was frequently observed preoperatively and postoperatively, but it did not prevent postoperative vision improvement. Preoperative IRF was related to lower postoperative vision improvement.