Remained Macular Edema After Surgical Treatment in Patients With Epiretinal Membrane

ABSTRACT

PURPOSE: To investigate the clinical features of patients with macular edema persisting for three months after a successful vitrectomy and removal of the epiretinal membrane. METHODS: The authors retrospectively reviewed the records of 32 patients (32 eyes) with epiretinal membranes who underwent pars plana vitrectomies and membranectomies from January 2005 to September 2008. The patients selected for the study underwent optical coherence tomography (OCT) which revealed macular edema. Macular edema is defined as central macular thickness measuring over 300 m. Several factors including age, presence of systemic disorders, preoperative visual acuity, surgical technique, preoperative state of the macula, and the response to treatment for macular edema were reviewed. RESULTS: Eight out of 32 eyes (25%) had no improvement of visual acuity after surgery of the epiretinal membrane. Six out of 32 eyes (18.75%) persisted in their macular edema. No common features were detected. All patients showed no improvement of visual acuity after their vitrectomies. Two of the eyes were treated with intravitreal or subtenon triamcinolone injection or non-steroidal anti-inflammatory eye drops. Only one eye (16.7%) achieved visual improvement as of the last follow-up. CONCLUSIONS: Despite a successful vitrectomy and membranectomy, macular edema can remain without any specific cause. Persistantmacular edema appears to be a main cause of poor visual outcome and tends to resist conventional treatment.