Worst-Fechner biconcave minus power phakic iris-claw lens

Abstract

Objective: Evaluation of long-term results of correction of high myopia by implantation of a biconcave Worst-Fechner minus power iris-claw lens into phakic eyes.

Methods: One hundred and twenty-seven eyes of 70 patients were implanted with the phakic IOL between November 1986 and November 1991. The mean preoperative spherical equivalent refraction was -14.29 +/- 5.77 D (range -5.00 to -31.75 D). The total population decreased from 127 to 68 eyes (53.5%) at the 8-year examination. By this time, 26 of the 70 patients (37%) had been lost to follow-up for unknown reasons. Corneal endothelial density was estimated by comparing the image gained by non-contact specular microscopy with a graduated reticule (Karickhoff method).

Results: At the 6-month examination, mean deviation of achieved from calculated refractive correction was +0.52 +/- 1.46 D (range -2.25 to +6.50 D). Seventy-seven eyes (62.1%) deviated 1.00 D or less, and 15 eyes (12.1%) deviated by more than 2.00 D from the calculated correction. A refractive outcome of +/- 1.00 D was attempted in 68 eyes (54% of the 124 eyes) and was achieved in 51 eyes (75%). Mean spectacle-corrected visual acuity preoperatively was 0.54 +/- 0.27 (range 1.20 to 0.05). At the 6-month examination it was 0.73 +/- 0.3, and by the 8-year examination had decreased to 0.65 +/- 0.26. Statistical analysis of corneal endothelial cell density revealed a significant correlation of endothelial cell loss with age (> or = 45 years), anterior chamber depth (< or = 3.4 mm), and IOL power (> or = -11.00 D). Seventeen eyes (13.4%) had a decrease in endothelial cell density and projection to 8-year follow-up resulted in a decrease in 27% of eyes. Four eyes needed a penetrating keratoplasty.

Conclusion: Implantation of a biconcave Worst-Fechner lens into a phakic eye effectively corrected high myopia with a stable refractive outcome, but 13.4% of implanted eyes suffered significant progressive reduction of endothelial cell density. This style lens is no longer in clinical use.