RESUMEN
One hundred sixteen eyes with cataracts were prospectively randomized into four surgical groups. Silicone and polymethylmethacrylate (PMMA) intraocular lenses were implanted into the posterior chamber of these eyes through 4-, 6-, or 11-millimeter incisions by one surgeon. Surgically-induced astigmatism was evaluated in terms of: (1) the proportion of eyes achieving a refractive cylinder of 1.5 or less, without regard to axis; and (2) the induced cylinder, with regard to axis, using vector analysis. One week postoperatively, the eyes with a 4-millimeter incision had a significantly lower mean induced cylinder than those with larger incisions (P = .019); and all three phacoemulsification groups had a significantly higher proportion of eyes with a cylinder of 1.5 or less than the nuclear expression group (P < .01). One month postoperatively, the 4-millimeter-incision group had a significantly lower mean induced cylinder (P = .044) as well as a significantly higher proportion of eyes with a cylinder of 1.5 or less, than the larger-incision groups (P = .05). Three months postoperatively, no value of any parameter in any group differed significantly from that of that parameter in any other group.