A method of reporting macular edema after cataract surgery using optical coherence tomography

Objective: To validate a method of reporting postcataract macular edema (ME) using optical coherence tomography (OCT). Methods: Data were analyzed for 130 eyes followed prospectively for ME after uncomplicated cataract surgery. Each eye underwent OCT within 4 weeks before surgery and at 1 month and 3 months after surgery. ME was defined by observation of cystoid changes by OCT. Results: Incidence of ME was 14% (95% confidence interval, 8-20). Average increase in baseline center point thickness (CPT) +/- SD at 1 month for eyes with and without ME was 202 +/- 113 mu m and 8 +/- 19 mu m, respectively (P < 0.001), which resulted in a 1-letter loss (-0.02 logMAR [logarithm of the minimum angle of resolution]) and a 3-line gain (0.29 logMAR) in vision, respectively (P < 0.001). Percent change in baseline CPT +/- SD for eyes with and without ME was 115 +/- 67% and 6 +/- 11%, respectively (P < 0.001). A >= 40% increase in baseline CPT accurately determined 100% of eyes with ME and 99% of eyes without ME. Conclusions: A >= 40% increase in baseline CPT, determined by OCT, offers a valid and objective method of reporting clinically relevant postcataract ME. Standardized reporting of postcataract ME would allow objective assessment and comparison of treatment outcomes among clinical studies.