Study of cystoid macular edema by optical coherent tomography following uneventful cataract surgery.

Abstract

The objective of this paper is to study the incidence of cystoid macular edema (CME) using optical coherence tomography (OCT) following uneventful small incision cataract surgery (SICS) and phacoemulsification. This was a descriptive, prospective study where 200 patients undergoing cataract surgery were randomly divided into two groups over a period of 1 year. Patients undergoing uneventful small incision cataract surgery were included in group I and patient undergoing uneventful phacoemulsification were included in group II, with 100 patients in each group. Preoperative assessment included best corrected visual acuity, detailed anterior segment and posterior segment evaluation, and intraocular pressure measurement. Macular thickness was measured using RTVue 100 three dimensional Fourier domain OCT, using Enhanced Macular Map 5 (EMM5) protocol. In group II, all the phaco parameters were also noted. Postoperative examination was done at day 1, 1 week, 1 month and 3 months for BCVA and macular thickness. Preoperative and postoperative measurements were analyzed statistically using ANOVA test, paired samples t test, and Pearson's correlation coefficient was calculated for different variables like phaco time, phaco energy, and BCVA. Statistically significant increase in macular thickness was detected postoperatively at 1 week (p ≥ 0.05 for group I and p = 0.1 for group II) and 1 month (p = 0.001 for group I and p ≤ 0.05 for group II), in all patients. It returned to near normal values by 3 months post operatively. This increase was mostly sub clinical. Overall incidence of clinical CME was 1.5%. Following SICS incidence of clinical CME was 2% and after phacoemulsification was 1%. BCVA was not affected in patients with subclinical CME but decreased vision was seen in patients with clinical CME. The incidence of subclinical and clinical CME was comparable in SICS and phacoemulsification, and subclinical CME did not have an impact on BCVA.