KPro visual acuity prognoses vary with type of underlying pathology
The Boston keratoprosthesis type 1 can produce significant visual recovery in eyes with debilitating corneal surface disease, but the amount of recovery may be associated with type of pathology, according to a study.
In a multicenter, prospective study of 300 eyes implanted with the Boston keratoprosthesis type 1 (Boston KPro) between January 2003 and July 2008, better final vision was achieved in eyes with underlying chemical injury.
The aim of the research by the Boston Type 1 Keratoprosthesis Study Group was to measure visual outcomes in eyes that underwent device implantation for varied injuries and diseases, including severe autoimmune disease, chemical injuries, herpes simplex keratitis, Fuchs’ endothelial dystrophy, keratoconus, infectious keratitis, neurotrophic ulcers, limbal stem cell deficiency, pseudophakic bullous keratopathy, trauma, aniridia, failed penetrating keratoplasty, miscellaneous and unknown.
There was a statistically significant improvement in visual acuity (P < .0001) of 9 lines, or a mean final acuity value of 20/150 Snellen equivalent (0.89 ± 0.64 logMAR) after 6 months. Median time to achieve 20/200 visual acuity was 1 month and that level of visual acuity was maintained for an average of 47.8 months.
“It is important to note that this average value describes 80.9% of the sample (n = 241); almost 20% of eyes will remain profoundly visually impaired after keratoprosthesis implantation,” the researchers wrote. Only 6% of eyes achieved final visual acuity better than 20/60.
Where eyes with chemical injury recovered better final vision, those with aniridia had the worst visual prognosis, attributable to its limited visual potential, according to the research. Among comorbidities, age-related macular disease was associated also with poorer final vision (P < .0001). – by Kate Sherrer
Disclosures: Rudnisky reports receiving speaking fees from Alcon and Bausch + Lomb, grant funding from Glaucoma Research Society of Canada, and has stock in Merck and Novartis. Please see the full study for the full list of all authors’ disclosures.