Outcome of phacoemulsification after pars plana vitrectomy

Purpose: To compare the outcome of phacoemulsification surgery in patients with and without prior vitrectomy, adjusted for confounding factors. Design: Retrospective cohort study. Participants and Controls: Thirty-one consecutive eyes undergoing phacoemulsification after pars plana vitrectomy (PPV) and 116 consecutive eyes undergoing phacoemulsification without previous PPV. Methods: Office records of the operating surgeons were reviewed for age, gender, type of cataract, vitrectomy status, best-corrected visual acuity (BCVA) before and after phacoemulsification, intraoperative difficulties, and postoperative complications. Bivariate analyses between these predictors and the main outcome, BCVA of 20/40 or better after phacoemulsification, were performed using Pearson's chi-square tests. An adjusted analysis of the relationship between outcome and vitrectomy status was performed with logistic regression. Pearson's chi-square tests were used to compare type of cataract, intraoperative difficulties, and postoperative complications in study and control eyes. Main Outcome Measures: BCVA of 20/40 or better after phacoemulsification, rates of intraoperative difficulties, and postoperative complications. Results: The most common indication for PPV was macular hole. The average interval from PPV to phacoemulsification was 15.4 months. Study eyes were followed for an average of 10 months compared with 6.6 months for controls. Study eyes were more likely than controls to have predominantly nuclear sclerotic cataracts (P = 0.002). After cataract extraction, 24 of 31 study eyes (77.4%) and 110 of 116 control eyes (94.8%), had BCVAs of 20/40 or better. After adjusting for confounders, eyes without previous vitrectomy were 3.44 times more likely to obtain a BCVA of 20/40 or better than eyes with prior PPV, but this difference was not statistically significant (95% Cl, 0.72-16.67). Only 3 of 31 (9.7%) study and 11 of 116 (9.4%) control eyes had intraoperative difficulties (P = 0.47). Posterior capsule plaque was the most common intraoperative difficulty in study eyes; small pupil requiring stretching or iris hooks was most common in controls. Only 1 of 31 (3.2%) study eyes had a postoperative complication other than posterior capsule opacification compared with 18 of 116 (15.5%) controls (P = 0.07). Conclusions: A large proportion of patients with prior PPV obtain good visual acuity after phacoemulsification. We did not find significantly higher rates of intraoperative difficulties or postoperative complications compared with controls. The benefits of phacoemulsification seem to be limited only by retinal comorbidity.