Postoperative posterior segment complications in eyes treated with the Boston type I keratoprosthesis

To describe the incidence, timing, visual significance, and management of posterior segment complications after Boston type I keratoprosthesis implantation.

A retrospective chart review was conducted of all consecutive Boston type I keratoprostheses implanted by a single surgeon at a single institution over a 6-year period. Preoperative demographics, postoperative complications, and postoperative visual acuity outcomes were analyzed.

One hundred and ten keratoprostheses were implanted in 98 eyes of 94 patients during the period under review. A minimum of 6-month follow-up was available for 83 eyes, with a mean follow-up of 28.2 months (range 6-84 months, median 23.7 months). The mean time to occurrence of any posterior segment complication was 5.6 months (range 0-42.1 months, median 5.2 months, n = 38). After keratoprosthesis surgery, 63% of all eyes had corrected distance visual acuity of 20/200 or better at last follow-up compared with 10% of eyes preoperatively. Thirty-eight eyes (40.9%) experienced at least 1 postoperative posterior segment complication, the most common of which were retinal detachment (16.9%, 14 of 83), choroidal detachment (16.9%, 14 of 83), and sterile vitritis (14.5%, 12 of 83). Corrected distance visual acuity was worse among eyes that experienced posterior segment complications compared with eyes that did not at multiple postoperative follow-up intervals (statistically significant up to 3 years) and at last follow-up (logarithm of the minimum angle of resolution ± SD = 1.45 ± 0.78 vs. 0.89 ± 0.81, P = 0.003).

Posterior segment complications occur in a significant percentage of patients after keratoprosthesis surgery, resulting in a persistent reduction of visual acuity in a significant proportion of the affected eyes (corrected distance visual acuity ≤ 20/400 in 61% with complications vs. 24% without complications at last follow-up). Given this, and the anatomic difficulties associated with management of posterior segment complications after keratoprosthesis implantation, it is of particular importance to prevent posterior segment complications, whenever possible, in keratoprosthesis patients.