Purpose:
The primary aim is to compare mean macular thickness among patients with intraoperative complication during phacoemulsification between those who developed postoperative cystoid macular edema (CME) and those who did not. The secondary objectives are to compare best-corrected visual acuity (BCVA) between these two groups and to analyze risk factors that lead to CME formation.
Methods:
This is a prospective cohort study. Patients who underwent phacoemulsification with intraoperative complication between July 2009 and June 2010 were recruited from the Ophthalmology Department, University of Malaya Medical Center, Malaysia. Average macular thickness as measured by spectral domain optical coherence tomography (SD-OCT) and BCVA were recorded at baseline (preoperatively), 1 week, 6 weeks and 16 weeks post-operatively. Patients’ characteristics, intraoperative complications and post-operative treatment were also collected. All statistical analyses were performed using R Version 2.13.1.
Results:
52 eyes of 51 patients were analyzed. 30.8% of eyes developed CME. In the CME group, the mean macular thickness at baseline (± standard deviation), 1 week, 6 weeks and 16 weeks were 273±24 µm, 286±29µm, 315±26µm and 329±31µm, respectively; in the non-CME group, they were 260±20µm, 264±21µm, 272±19µm and 274±25µm, respectively. The mean BCVA (± standard deviation) at the same four time periods were 0.92±0.66, 0.98±0.22, 0.66±0.36 and 0.66±0.41 respectively in the CME group, and 1.05±0.64, 0.80±0.41, 0.25±0.23, 0.29±0.49 respectively in the non-CME group. Baseline mean macular thickness (p=0.06) and mean BCVA (p=0.5) between the two groups (CME against non-CME) were not statistically significant. At 16 weeks, the two groups differed significantly in mean macular thickness (difference in mean=53 μm; 95% CI: [31, 74]) and mean BCVA (difference in mean = -0.35; 95% CI: [-0.68, -0.05]). Patient’s diabetic status (p=0.04) and operation time (p=0.02) were found to be significant risk factors in the development of CME.
Conclusions:
The rate of detection of CME using SD-OCT is higher compared to previous clinical and angiographic studies. Close monitoring of at-risk patients with OCT allows early detection and treatment of CME.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • cataract • edema