The Boston Type I Keratoprosthesis: An Assessment of Its Efficacy and Safety

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of the Boston Type I keratoprosthesis. PATIENTS AND METHODS: Twelve patients who underwent surgery with implantation of the Boston Type I keratoprosthesis were monitored. The following parameters were considered: diagnosis, comorbidity, previous surgery, preoperative and postoperative visual acuity, complications, and keratoprosthetic retention. RESULTS: The follow-up period ranged from 6 to 42 months (mean: 23 months). The mean number of previous keratoplasties was 2.0. The percentage of patients whose best-corrected visual acuity improved was 83.3%, and 16.7% maintained their previous vision. No patient had preoperative visual acuity better than 0.05. Patients with glaucoma comorbidity had the most limited final postoperative vision. Four eyes presented limited corneal melt. In another two eyes, corneal stromal bleeding led to a vitreous hemorrhage that was completely resolved after some weeks. No endophthalmitis or extrusion of the device occurred. CONCLUSION: The Boston Type I keratoprosthesis has a visual rehabilitation potential in cases of complicated corneal blindness, where the prognosis of a conventional keratoplasty is considered poor. Anatomical retention may be favorable in the medium term.