Abstract
Purpose:
The Boston type 1 keratoprosthesis (KPro) is the most commonly used keratoprosthesis in the US and the world,with more than 7,000 implantations to date. A high proportion of candidates for this device are elderly. The objectives of this study are to identify surgical indications,device retention rate at the 3 month postoperative period and the proportion of patients that achieved at least 20/200 vision,which is normally considered the threshold for safe ambulation,in order to predict device “success” for patients later in life who are less likely to experience late complications.
Methods:
The charts of patients who underwent keratoprosthesis surgery at Massachusetts Eye and Ear Infirmary between January to December 2011 were retrospectively reviewed.
Results:
The type 1 KPro was implanted in 28 patients for the first time during the year 2011. Of these 28 patients, 27 had at least 3 months of follow-up data and were included in the analysis. The patients’ age ranged from 37 to 86 years of age with an average of 64.8. 15 (55.5%) patients were over the age of 65. Indications for surgery included failed grafts(66.7%),corneal opacity(14.8%),bullous keratopathy(7.4%),aniridia(3.7%),Stevens Johnson Syndrome(3.7%),and pemphigoid(3.7%). The majority (70.4%) of these patients had prior traditional corneal transplants, but a minority (29.6%) received it as a primary procedure. Of the 27 patients analyzed, 18 (66.7%) achieved at least 20/200 vision within the 3 month postoperative period. Of the 9 patients who did not achieve a postoperative vision of at least 20/200, 8 had preexisting severe retinal disease or glaucoma, which limited visual prognosis. Only 1 of the 9 patients with potential for at least 20/200 vision failed to achieve it, due to a dense retroprosthetic membrane. Of those 15 patients over the age of 65, 10 (66.7%) achieved at least 20/200 vision within the 3 month postoperative period. 100% of the 27 patients retained the keratoprosthesis at the 3 month postoperative period.
Conclusions:
Our study demonstrates excellent short term device retention. A majority of the patients achieved at least 20/200 vision within the 3 month postoperative period. The Boston type 1 keratoprosthesis remains a viable option for salvaging vision in older patients with corneal disease in which traditional keratoplasty would carry a poor prognosis.
Keywords: 575 keratoprostheses