Effect of Anterior Capsulotomy Shape and Intraocular Lens Design on Lens Decentration

OBJECTIVE: To determine whether the anterior capsulotomy shape (capsulorhexis or envelope) or the IOL design (polyHEMA, one-piece PMMA open and closed loops, three-piece polypropylene and PMMA loops) influence the lens decentration after intercapsular cataract surgery. STUDY DESIGN: Retrospective study of postoperative results 18 months after surgery. SETTING: University Eye Clinic of Trieste, Italy. PATIENTS: 150 patients divided into two groups: in 75 cases anterior circular continuous capsulorhexis (CCC) was performed and in 75 cases the envelope technique was used. Only patients with uncomplicated eyes and absence of posterior capsular opacification were included. MAIN OUTCOME MEASURES: Degree of IOL decentration was measured by projecting a slide of the anterior segment of the eye, taken after maximum dilatation, and calculating the distance between the circles formed by the corneoscleral limbus and the edge of the IOL. RESULTS: Including all IOLs, mean decentration was 0.28 ± 0.21 mm in the capsulorhexis group and 0.55 ± 0.32 mm in the envelope group; the difference is statistically significant ( P