摘要：Pu.pose: To compare posterior capsu.e opacification (PCO) after cataract su.ge ry with implantation of two silicone intraocu.ar lenses (IOLs) with different de signs. Methods: We carried ou. a prospective, clinical stu.y of 116 patients ran domized to standardized phacoemu.sification with implantation of CeeOnEdge (n=57 ) or SI40NB (n=59) IOLs. The follow-u. period was 3 years. To evalu.te PCO morp hologically, digital images were obtained and analysed u.ing evalu.tion of poste rior capsu.e opacification compu.er software (EPCO). The neodymiu.:YAG (Nd:YAG) capsu.otomy rate was recorded. Resu.ts: At 2 and 3 years, the eyes with SI40NB I OLs had significantly more PCO than those with the CeeOn Edge IOLs (p=0.00014 an d p=0.002). Nine Nd:YAG capsu.otomies were performed in the SI40NB grou. and non e in the CeeOn Edge grou.. This difference was statistically significant (p=0.00 3). In some patients a regression of PCO was noticed and confirmed u.ingEPCO. St atistically less PCO was noted when the capsu.orhexis rim was placed so that it covered all 360 degrees of the optic of the IOL. Conclu.ions: A clinically and s tatistically significant difference in PCO development between CeeOn Edge and SI 40NB IOLs at 2 and 3 years postoperatively was fou.d. These findings su.port earlier stu.ies indicating that a sharp edge of the opt ic is a more important factor in IOL design than IOL material in the prevention of PCO.