Cystoid macular edema after phacoemulsification: risk factors and effect on visual acuity

Background: To determine the incidence and risk factors for cystoid macular edema (CME) after phacoemulsification surgery and its effect on visual acuity. Methods: This prospective study evaluated 98 eyes of 98 patients (43 women) with a mean (SD) age of 61.8 (11.3) years. Phacoemulsification was performed with temporal clear corneal incision and implantation of foldable hydrophilic acrylic intraocular lens in the bag. Postoperative visits were on day 1, week 1, and at 1, 3, and 6 months. In addition, at week 10 all patients had fundus fluorescein angiography, and presence of CME was determined. Age, sex, iris colour, pseudoexfoliation, type of cataract, phaco time, status of the posterior vitreous, iris trauma, severity of anterior chamber reaction, and visual acuities were evaluated. Results: No major intraoperative complications occurred. Twenty-five (25.5%) eyes were CME(+), and 73 (74.4%) eyes were CME(-). CME occurred in 70% of patients with iris trauma and 20.5% of patients with no iris trauma. CME was more common in patients who had postoperative anterior chamber inflammation of 2+ or more than in patients with less inflammation (43.2% vs. 11.5%). Complete posterior vitreous detachment had some apparent protective effect against CME development. The mean visual acuities of CME(+) patients were lower than those of CME(-) patients in all postoperative periods. The difference was significant in the third month (P < 0.05). Interpretation: CME after phacoemulsification was associated with iris trauma and severe postoperative inflammation. Complete posterior vitreous detachment had some apparent protective effect against CME development. CME may be associated with decreased visual acuity.