Long-term visual results of bifocal intraocular lens implantation

Purpose: To evaluate the long-term visual results and variability in contrast sensitivity in patients with heparin-surface-modified (HSM) diffractive bifocal intraocular lenses (IOLs). Setting: Institute of Ophthalmology, University of Catania, Italy. Methods: In this prospective study, visual acuity (distance and near)and contrast sensitivity were measured in 35 patients who had phacoemulsification with bifocal diffractive IOL (model 811E, Pharmacia) implantation. Patient satisfaction was also evaluated using a questionnaire. Mean follow-up was 20 months (range 18 to 24 months). Results: At the last examination, mean distance visual acuity was 0.79 +/- 0.2 (SD) without correction and 1.0 +/- 0.15 with best correction. Mean uncorrected near visual acuity was J1.6 +/- J0.77 and with best distance correction, J1.19 +/- J0.49. No statistically significant changes in visual acuity were evident at the last follow-up (Student t test). No changes were found in contrast sensitivity reduction over time, nor were late postoperative complications noted. Overall patient satisfaction was rated as good by 94.3% of patients with best distance correction. Conclusions: The diffractive bifocal HSM IOL provided good visual performance for distance and near over time. In relation to the low rate of postoperative complications, the slight contrast sensitivity reduction was stable during follow-up. (C) 1999 ASCRS and ESCRS.