For Patients With Keratoprosthesis Implant, Perform Glaucoma Surgery Promptly

Doctors performing surgery on patient in ICU
Male doctor looking through microscope while treating patient. Surgeons performing eye surgery in emergency room. They are wearing scrubs in ICU.
Researchers say eyes with a Boston keratoprosthesis type 1 that underwent glaucoma surgery earlier had better visual outcomes.

For eyes with a Boston keratoprosthesis type 1 (KPro) implant, glaucoma surgery should be performed as early as possible to optimize visual potential. These findings, from a single-center, case-series study, were published in the American Journal of Ophthalmology.

Researchers from the Centre hospitalier de l’Université de Montréal in Canada reviewed medical records of patients (N=100) who received a KPro implant between 2008 and 2017. Clinical outcomes from glaucoma drainage device implantation, cyclophotocoagulation, or trabeculectomy surgical procedures for glaucoma were assessed on the basis of whether glaucoma was present prior to KPro implantation or occurred de novo after the procedure.

Patients with preexisting glaucoma (n=72) and de novo glaucoma (n=28) were 56.9% and 53.6% men, aged mean 62.7 and 61.1 years, 54.2% and 60.7% had their right eye operated on, and mean follow-up time was 6.7 and 7.8 years, respectively. Patient cohorts were well balanced except that more eyes with preexisting glaucoma had a prior graft (63.9% vs 39.3%; P =.026).

Among the preexisting cohort, 37.5% underwent glaucoma surgery prior to or at the time of KPro surgery, 26.4% underwent surgery after KPro implantation, and the remainder (36.1%) used medication only. These groups differed significantly for glaucoma progression (74.1% vs 100% vs 53.8%; P =.002), hypotony (14.8% vs 21.1% vs 46.2%; P =.035), retinal detachment (7.4% vs 5.3% vs 30.8%; P =.027), and phthisis bulbi (3.7% vs 5.3% vs 26.9%; P =.041), respectively.

Among the de novo cohort, 42.9% underwent glaucoma surgery and 57.1% managed glaucoma with medication. No significant differences were observed for glaucoma outcomes between these cohorts.

Among all patients, the proportion of patients who retained best-corrected visual acuity (BCVA) ≥20/200 did not differ between the surgical groups (before vs after KPro implantation) but the patients who used medicinal interventions alone associated with more rapid visual decline (P =.013).

This study was limited by not having sufficient power to assess various glaucoma surgical procedures separately.

The study authors report that surgical interventions for eyes with a KPro implant should be performed as early as possible in order to maintain visual acuity. In addition, medicinal management alone was not effective at maintaining visual outcomes compared with surgery.


Geoffrion D, Hassanaly SI, Machand M, Daoud R, Agoumi Y, Harissi-Dagher M. Assessment of the role and timing of glaucoma surgery in Boston keratoprosthesis type 1 patients. Am J Ophthalmol. Published online September 17, 2021. doi:10.1016/j.ajo.2021.09.005