Boston keratoprosthesis type 1: outcomes of the first 38 cases performed at Moorfields Eye Hospital

To evaluate outcomes of Boston keratoprosthesis type 1 (K-Pro) surgery in a cohort of high-risk patients at Moorfields Eye Hospital. Our patients were referred to us at the end-point of their ocular disease.

A retrospective review of all K-Pro surgery performed between March 2011 and July 2015 with a minimum follow-up of 12 months.

39 eyes of 38 patients were included. Mean follow-up was 28.4 months (range: 12-56). The main indication for surgery was bullous keratopathy from multiple failed grafts (56%). 26 cases (72.2%) had known posterior segment disease pre-operatively. Mean BCVA for the entire cohort (n = 39) initially improved from HM vision to 1/60 before returning to CF vision by 6 months and was maintained for the duration of follow-up. By final follow-up (n = 39), 46% had improved vision (1 line improvement in 10%; 2 lines or more in 36%) and 31% maintained pre-operative visual acuity. Anterior segment pathology was not an independent variable in visual outcome. However, absence of posterior segment disease was significant and performed best, improving from HM to 6/15 and maintaining that vision in the longer term. There were 13 (33%) cases of progressive glaucomatous optic neuropathy, 10 (26%) retinal detachments, 8 (21%) retroprosthetic membranes, 3 (8%) infective keratitis and 2 (5%) vitritis of which 1 progressed to endophthalmitis. In all, 3 (8%) had NPL vision and 4 (10%) required removal of the K-Pro.

Implantation of the Boston K-Pro can lead to improved vision, with the main limiting factor being posterior segment pathology.