Closed-system technique for implantation of iris-supported negative-power intraocular lens

The iris-supported claw lens can reversibly correct a wide range of ametropia and aniseikonia with excellent predictability and stability. However, concerns regarding its potential harm to the corneal endothelium have prevented its widespread use. Our experience with the closed-system surgical technique and the spreader device used in 180 cases between 1987 and 1993 has led us to conclude that potential complications are more likely due to the technique of implantation rather than to the properties of the lens itself.

We conducted a prospective study of 35 eyes of 20 consecutive patients (mean age, 38 years; range, 21 to 55 years) operated on between August 1993 and August 1994. Preoperative spherical equivalent refractions ranged from -6.00 to -21.25 diopters (D) (mean, -12.50 D). Follow up was 6 months (86% of eyes) to 1 year (57% of eyes). Spectacle-corrected visual acuity and endothelial cell density were measured prior to, and 1, 6, and 12 months following lens implantation. All data were analyzed using the paired t-test.

Mean endothelial cell density dropped insignificantly (p > .10):by 1.22% at 1 month (n = 34), by 2.25% at 6 months (n = 27), and by 1.21% at 12 months (n = 18). Spectacle-corrected visual acuity increased significantly (p < .001): from a mean of 0.61 preoperatively to 0.77 at 1 month, 0.84 at 6 months, and 0.93 at 12 months postoperatively. At 12 months, 15 eyes (75%) had a refraction within +/-0.50 D, 19 eyes (95%) within +/-1.00 D, and 20 eyes (100%) within +/-2.00 D of emmetropia.

Our results suggest that the closed-system approach using the spreader device allows safe implantation of the Worst iris-supported claw lens.