Symptomatic aniseikonia in unilateral and bilateral pseudophakia. A projection space eikonometer study.
PURPOSE: To determine the incidence of aniseikonia and aniseikonic symptoms in pseudophakia (intraocular lens implantation after cataract extraction). METHOD: Aniseikonia, stereoacuity, and clinical symptoms were evaluated in patients with unilateral and bilateral pseudophakia. Aniseikonia was determined with the Essilor projection space eikonometer. Eight-seven cases were studied, fifty-four of unilateral pseudophakia and thirty-three of bilateral pseudophakia. Nine of the 87 patients had insufficient stereopsis to be examined or measured for aniseikonia with the Essilor instrument, and were studied with the "Double-D", a two dimensional "direct comparison eikonometer" device programmed and viewed on a computer. Stereoacuity was determined with the Titmus Stereo Test. RESULTS: Thirty-five (40.2%) of all pseudophakes had ophthalmic complaints referable to aniseikonia. The mean aniseikonia in the unilateral pseudophakia group was 4.1%, SD=3.41, while the mean aniseikonia in the bilateral group was 3.2%, SD=2.6. CONCLUSION: Symptomatic aniseikonia is common in pseudophakia. Unilateral pseudophakia has the higher degrees of aniseikonia, and is at a greater risk of loss of binocularity and of asthenopia.