Researchers reviewed five-year Boston keratoprosthesis outcomes in 194 patients from seven countries outside of North America - Armenia, India, Indonesia, Nepal, Philippines, Russia, and Saudi Arabia - and compared them to outcomes at Jules Stein Eye Institute at UCLA. A single surgeon from Jules Stein trained all of the corneal surgeons from the seven countries.
Although corneal transplant failure was the most common indication in both series, it was significantly less common in the international series. Conversely, chemical injury was a significantly more common indication for surgery in the international series.
Visual acuity outcomes and rates of postoperative complications were similar to those obtained by North American surgeons. The most common postoperative complications were retroprosthetic membrane formation (27 percent) and sterile corneal necrosis (18 percent). The only postoperative complication that was more common in the international series than in the Jules Stein series was infectious endophthalmitis, which developed in 9 percent of eyes, compared to 1 percent of eyes in the Jules Stein series.
The keratoprosthesis retention failure rate in the international series was higher than in the Jules Stein series. The authors write that this may be the result of a number of factors, including earlier diagnosis and management of persistent corneal epithelial defects, and greater patient adherence to the prescribed medication and contact lens regimen at Jules Stein.
They conclude that although this report provides initial evidence that the Boston keratoprosthesis is a viable means of restoring functional vision to most recipients outside of North America, larger numbers of patients and longer follow-up are needed to develop customized management regimens for each locale based on the varied indications for surgery and the regional, cultural, environmental, and economic factors that may influence postoperative outcomes.