Visual Outcomes of Boston Keratoprosthesis Implantation as the Primary Penetrating Corneal Procedure

Purpose: To report the short-term visual outcomes and complications of keratoprosthesis surgery as the primary penetrating corneal procedure for patients at high risk for conventional corneal transplantation. Methods: A retrospective chart review was conducted of 21 eyes of 19 patients who underwent either Boston keratoprosthesis type I or type II as the primary penetrating corneal procedure from February 2007 to March 2011. Results: Nineteen type I (90.5%) and 2 type II (9.5%) Boston keratoprosthesis procedures were performed in 19 patients. Mean follow-up was 14.6 months (range, 6-36.3 mo). Primary indications for surgery included chemical or thermal injury, aniridia, and Stevens-Johnson syndrome. Preoperative best-corrected visual acuity (BCVA) ranged from 20/100 to light perception and was count fingers or worse in 20 eyes (95.2%). At last follow-up for all eyes, 15 eyes (71.4%) achieved BCVA >= 20/200 and 4 eyes (19%) improved to BCVA >= 20/50. No intraoperative complications occurred. Postoperative complications include retroprosthetic membrane formation (47.6%), cystoid macular edema (33.3%), elevated intraocular pressure (23.8%), glaucoma progression (14.3%), and endophthalmitis (4.8%). The initial keratoprosthesis was retained in 19 eyes (90.5%). Conclusion: The Boston keratoprosthesis, based on early follow-up, is a good alternative as a primary penetrating corneal procedure in a select group of patients with very poor prognosis for penetrating keratoplasty. Although complications can occur and require close monitoring, visual acuity significantly improved in the majority of patients.