Comparison of the unwanted optical images produced by 6 mm and 7 mm intraocular lenses.

Unwanted optical images are noticed by a surprisingly large number of patients following cataract extraction with implantation of posterior chamber intraocular lenses (IOLs). These images are caused by the positioning holes, lens edge, or laser ridge. We studied 550 eyes in which one of seven different IOLs was inserted. The IOLs varied in optic diameter, the presence or absence of positioning holes or a laser ridge, the use of partial depth holes or placement of positioning holes in tabs outside the optical zone. We determined that unwanted optical images could practically be eliminated by using a 7 mm optic without positioning holes. This study also demonstrated that partial depth holes offer no advantage over full thickness holes for reducing unwanted optical images and that positioning holes, even on a 7 mm optic, produce a significant number of complaints.