Boston Keratoprosthesis Type II: Indications, Techniques, Outcomes, and Management

Implantation of a keratoprosthesis device is indicated for the visual rehabilitation of patients with corneal blindness in whom a standard corneal allograft would likely fail. The Boston keratoprosthesis type I device is a collar button-shaped device, composed of polymethyl methacrylate and titanium, whereas the type II device has an additional anterior extension that allows for implantation through surgically closed eyelids. The type I device is used in patients with intact eyelids, normal blink, and adequate tear film. The type II device is reserved for patients with abnormal lid function and tear secretion, forniceal foreshortening, and ocular surface keratinization. Herein, we focus on the indications, preoperative assessment, surgical technique, and postoperative care for the Boston keratoprosthesis type II and provide advice on management of complications