The effect of capsulorhexis size on development of posterior capsule opacification:: Small (4.5 to 5.0 mm) versus large (6.0 to 7.0 mm)

PURPOSE. The most common surgically related cause of reduced vision after extracapsular cataract extraction is posterior capsule opacification (PCO), which occurs in up to 50% of eyes following cataract extraction. This study examined whether small capsulorhexes of 4.5 to 5.0 mm, which lie completely on the 5.5 mm intraocular lens (IOL), and large capsulorhexes of 6.0 to 7.0 mm, which lie completely off the lens optic, are effective in preventing PCO development. METHODS. In this prospective study, 496 eyes of 367 patients underwent standardized phacoemulsification with capsulorhexis and capsular bag foldable acrylic IOL implantation. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the IOL optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Retroillumination photographs were taken at 6 months and then yearly. RESULTS. Throughout the follow-up, there was less PCO in the small capsulorhexis group than in the large capsulorhexis group. CONCLUSIONS. Small capsulorhexes were associated with less wrinkling of the posterior capsule and less PCO than were large capsulorhexes. PCO after IOL implantation has a multifactored pathogenesis. Small (4.5 to 5.0 mm) capsulorhexis and capsular bag implantation of 5.5 mm acrylic IOL are likely to reduce the PCO incidence when compared with the 6.0 to 7.0 mm capsulorhexis. The significance of the IOL optic diameter in association with the capsulorhexis size should also be documented by further studies.