Pathogenesis of posterior capsular opacification. Part I. Epidemiological and clinico-statistical data.

We examined 895 eyes having extracapsular cataract surgery; 403 had an intraocular lens (IOL) implanted and 492 did not. The incidence of posterior capsular opacification was 7.69% in the eyes with an IOL and 14.23% in the eyes without an IOL. If we exclude complicated cataracts from the cases that did not have an IOL, the incidence of posterior capsular opacification decreases to 9.06%. Various models of implanted IOLs showed different incidences of posterior capsular opacification: For J-looped lenses the incidence was 11.02%; for Frezzotti-Caporossi lenses, 7.35%. The follow-up was too short for soft lenses. The Frezzotti-Caporossi lens can be inserted with the convex side either anterior or posterior. A statistical evaluation shows that the reverse optic or posterior convex orientation in the bag caused a lower incidence of posterior capsular opacification (3.01%).