Implantation of the black diaphragm intraocular lens in congenital and and traumatic aniridia

Objective: To evaluate the biometry accuracy, visual outcomes, and long-term changes in intraocular pressure after implantation of the black diaphragm intraocular (BDI) lens in cases of aniridia. Design: Retrospective, interventional case series. Participants: Forty eyes of 35 patients with aniridia (15 eyes of congenital origin and 25 as a result of trauma). Methods: Patient demographics, clinical evolution, and treatment were analyzed for each case undergoing implantation with the Morcher 67F BDI lens (Morcher GmBH, Stuttgart, Germany). Main Outcome Measures: Biometry accuracy, visual outcome, and the development of glaucoma and other complications in these eyes over a mean of 3.5 years. Results: Using the recommended A constant of 118.7, the mean biometry prediction error was -0.12 +/- 0.44 diopters (D), with a mean absolute error of 1.47 +/- 0.29 D, equivalent to 80% of target eyes being within 2 D of predicted refraction. The prevalence of glaucoma increased from 10 (25%) of 40 eyes before surgery, to 22 (55%) of 40 eyes at 1 year after surgery. The best-corrected visual acuity in logarithm of the minimum angle of resolution (logMAR) units improved significantly in the 25 eyes with traumatic aniridia, from 1.34 +/- 0.22 to 0.54 +/- 0.16 (20/400 to 20/70; P<0.001). In contrast, no significant improvement was seen in the 15 eyes with congenital aniridia, whose preoperative logMAR visual acuity of 1.17 +/- 0.14 improved to 1.01 +/- 0.21 (20/300 to 20/200; P = 0.20). Conclusions: Biometry is reasonably accurate when implanting the BDI lens for aniridia. Glaucoma is the main complication and occurred immediately after surgery, suggesting a possible direct mechanical effect of the large BDI lens. Significantly better visual outcomes were seen when using the 67F BDI lens for traumatic aniridia compared with congenital aniridia. Implantation of the BDI lens in congenital aniridia therefore should be approached with caution, because the recreation of an iris diaphragm does not confer the expected optical benefits in these eyes.