Risk of Zonular Dialysis in Fellow-Eye Cataract Surgeries: A Multicenter Comparative Study.

Purpose: To evaluate the risk of zonular dialysis (ZD) in fellow eye phacoemulsification cataract surgery and to identify risk factors, including prior first eye ZD.

Setting: 8 United Kingdom National Health Service clinical centers.

Design: Retrospective database study.

Methods: We calculated the overall risk of ZD in the fellow eye and reported the odds ratio (OR) for the various risk factors, including first eye ZD. The main outcome measures were the risk and the predictors of intraoperative ZD in the fellow eye.

Results: There was a total of 66,288 patients. At the time of the first surgery, the mean age of patients was 75.3±10.2 years, and 39.2% were males. Intraoperative ZD occurred during the first eye surgery in 333 patients (0.5%) and the fellow eye in 349 patients (0.5%). The risk of fellow eye developing ZD in patients with first eye ZD was higher than in patients without first eye ZD: 23/333 patients (6.9%) vs. 326/65,955 patients (0.5%) (p<0.001, unadjusted OR=14.9). In the adjusted logistic regression model, first eye ZD was the most significant risk factor (OR=13.3, 95% confidence interval (CI) =8.2-21.7). Other significant covariates of ZD in the fellow eye were pseudoexfoliation (OR=6, CI=3.8-9.7), previous pars-plana vitrectomy (OR=4.5, CI=1.1-18.5), and poor pupillary dilatation (OR=2.2, CI=1.4-3.3).

Conclusions: The most important risk factor for the development of ZD in the fellow eye during cataract surgery was the occurrence of ZD in the first eye. Our findings have implications for patient counseling and surgery allocation.