ANGLE-FIXATED ANTERIOR-CHAMBER PHAKIC INTRAOCULAR-LENS FOR MYOPIA OF -7 TO -19 DIOPTERS

PURPOSE: To assess the safety and efficacy of a second generation, ant erior chamber phakic intraocular lens (Baikoff Model ZB5M) in patients with high myopia. METHODS: One hundred and twenty-one patients (134 e yes) with myopia of -7.00 to -18.80 D were implanted with the ZB5M len s and followed for 18 to 52 months; the number of eyes evaluated was: 6 months (104 eyes), 1 year (91 eyes), 18 months (78 eyes), 2 years (6 8 eyes), and 3 years (35 eyes). RESULTS: Postoperative spherical equiv alent refraction averaged -1.00 D and the error in refractive correcti on (achieved minus intended) averaged -0.40 D during the first 2 years , increasing -to -1.30 D refraction and -0.60 D error in refractive co rrection at 3 years. At 2 years, approximately 40% of eyes had a spher ical equivalent refraction within +/-0.50 D, and 65% within +/-1.00 D, The uncorrected distance visual acuity was 0.048 at baseline and 0.5 at 3 years; near visual acuity was 0.21 at baseline and approximately 0.7 over the 3 years of follow-up. Spectacle-corrected distance visual acuity at baseline was 0.54; it improved to 0.7, Near visual acuity w as 0.65 at baseline and it improved to approximately 0.75, Endothelial cell counts in the central and peripheral cornea were reduced by an a verage 3.3% at 6 months, declining an additional 1% to 2% over the rem aining follow-up period. Regression analyses indicated that most of th e endothelial cell loss was due to surgery, Additional complications i ncluded halos/glare in 37 of 133 eyes (27.8%) and iris retraction with pupillary ovalization in 30 of 133 eyes (22.6%). The intraocular lens was exchanged in four of 133 eyes (3.0%) and removed in three of 133 eyes (2.3%), the latter because of halos (one eye) and a flat anterior chamber with severe inflammation (two eyes), CONCLUSIONS: Implantatio n of the Baikoff ZB5M lens in the anterior chamber of phakic eyes sign ificantly reduced high myopia and produced a stable refractive outcome over the 3 years, accompanied by marked improvement in uncorrected di stance visual acuity and minimal, non-progressive damage to the cornea l endothelium, Frequent complications included pupillary ovalization a nd halos/glare, Improvements in accuracy of IOL power calculations are needed.