Correlation between Severity of Idiopathic Epiretinal Membrane and Irvine–Gass Syndrome

A higher risk of pseudophakic cystoid macular edema (PCME) has been reported in patients with preoperative idiopathic epiretinal membrane (ERM); however, whether the formation of PCME depends on the grade of ERM has not been well established. We conducted a retrospective case–control study of 87 eyes of 78 patients who were preoperatively diagnosed with idiopathic ERM and had undergone cataract surgery. Patients were divided into two groups: PCME and non-PCME groups. After cataract surgery, the ERM status was graded using the Gass and Govetto classifications. Both the central macular thickness (CMT) and ERM grade increased after surgery, and higher preoperative CMT and ERM grades were found in the PCME group. The association between higher-grade ERM and the development of PCME was significant in the Govetto classification (grade 2, odds ratio (OR): 3.13; grade 3, OR: 3.93; and grade 4, OR: 16.07). The study results indicate that close attention should be given to patients with ERM with the presence of an ectopic inner foveal layer before cataract surgery.