Incidence of and risk factors for residual posterior capsule opacification after cataract surgery

Purpose: To evaluate the incidence of and determine the risk factors for residual posterior capsule opacification (PCO). Setting: University of New Mexico Health Sciences Center and the Veterans Administration Medical Center, Albuquerque, New Mexico, USA. Methods: This study evaluated 194 uneventful cataract surgeries. Immature cataracts were graded for nuclear sclerosis (NS), posterior subcapsular cataract (PSC), and anterior cortical spokes on a 1 to 4 scale. Preoperative Snellen best corrected visual acuity was converted to the logMAR scale. The posterior capsule was examined after polishing and was classified as clear or as having residual opacity. Those with residual capsule opacity were evaluated 6 weeks postoperatively for the presence of visually significant PCO. Results: The incidence of residual capsule opacity was 23% (44 eyes). Seven (54%) of 13 eyes with white mature cataract had residual capsule opacity. In contrast, 37 (20%) of 181 eyes with immature cataract had residual capsule opacity (P = .01). In eyes with immature cataract, the mean preoperative logMAR acuity was +1.14 ± 0.60 (SD) in the residual capsule opacity group and +0.73 ± 0.46 in the clear group (P<.001). In eyes with immature cataract, the adjusted odds ratio for each increasing grade of NS was 2.3 and of PSC, 1.8 (P = .002 and P<.001, respectively). Eleven percent (5 eyes) of residual capsule opacities resulted in visually significant PCO 6 weeks postoperatively. All 5 opacities were centrally located at surgery. Conclusions: Results indicate that aggressive polishing of peripheral or adherent residual capsule opacities is not advisable as only 5 eyes with central residual capsule opacities developed visually significant PCO.