Risk factors for and diagnosis of pseudophakic cystoid macular edema after cataract surgery in diabetic patients

Abstract

Purpose: To evaluate the risk factors and potential diagnostic criteria for pseudophakic cystoid macular edema (CME) in diabetic patients after phacoemulsification.

Setting: Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China.

Design: Prospective nonrandomized study.

Methods: Diabetic patients were followed for up to 6 months after cataract surgery and examined to evaluate their foveal thickness, macular sensitivity, and corrected distance visual acuity. Multiple statistical analyses were performed to determine risk factors and diagnostic criteria for pseudophakic CME.

Results: The duration, type of diabetes, stage of diabetic retinopathy, nuclear opalescence grading, glycosylated hemoglobin A_1c (HbA_1c), and ultrasound time were correlated with the change in foveal thickness and macular sensitivity after cataract surgery. Unsupervised data analysis showed 3 groups of patients as follows: nonpseudophakic CME, level 1 pseudophakic CME, and level 2 pseudophakic CME. Subclinical level 1 patients had a 30% to 40% increase in foveal thickness 1 month postoperatively, while level 2 patients had at least a 40% increase in foveal thickness and a 20% decrease in macular sensitivity. The incidence of clinical pseudophakic CME was 3.2% in diabetic patients as per the diagnostic criteria. The change in macular sensitivity was more consistent and correlated with foveal thickness.

Conclusions: The duration, severity, type of diabetes, hardness of the lens, and HbA_1c were risks for pseudophakic CME in diabetic patients after cataract surgery. A 40% or more increase in foveal thickness and 20% or more decrease in macular sensitivity offer an objective and reliable diagnostic standard to report pseudophakic CME in diabetics.