Visual outcomes of primary keratoprosthesis implantation in transplant-naïve eyes

Primary keratoprosthesis (Kpro) implantation may be indicated in eyes that have an expected poor prognosis following initial penetrating keratoplasty, such as eyes with limbal stem cell deficiency (LSCD). We compare visual outcomes of eyes undergoing primary Kpro to eyes that had a secondary Kpro following penetrating keratoplasty.

Retrospective review of all patients who had Kpro implantation at a tertiary academic medical center from 2005-2020. Among those, eyes that had undergone primary Kpro implantation without a history of prior corneal transplantation were also identified.

Eighty-four eyes of 77 patients that had undergone Kpro implantation were identified. Of those 84, 12 eyes (21.4%) of 12 patients were receiving primary Kpro since they were corneal transplant-naïve. Among individuals undergoing primary Kpro implantation compared to secondary Kpro implantation, the most common underlying diagnoses were limbal stem cell deficiency (41.7% vs 10.0%, p = 0.01304), corneal scarring not otherwise specified (25.0% vs 2.86%, p = 0.02077), and neurotrophic cornea (16.7% vs 2.86%, p = 0.1002). Eyes undergoing primary Kpro implantation had similar mean visual acuity to eyes undergoing secondary Kpro preoperatively (20/2118 vs 20/3786, p = 0.271), 3 months postoperatively (20/264 vs 20/758, p = 0.174), and at final follow up (average 3.06 years, 20/907 vs 20/3446, p = 0.070). Average follow-up time and rates of glaucoma, endophthalmitis, retroprosthetic membrane, and retinal detachment did not significantly differ between groups (all p > 0.05). All eyes that progressed to no light perception (n = 13) had undergone secondary Kpro implantation.

Visual acuity outcomes were similar between primary Kpro implantation and secondary Kpro implantation. Eyes that underwent primary Kpro implantation trended toward better postoperative VA at final follow-up than secondary Kpro eyes.