Glaucoma outcomes following Boston Keratoprosthesis Type 1 surgery
First Author: D.Geoffrion CANADA
Co Author(s): M. Harissi-Dagher
To evaluate and understand glaucoma visual outcomes of the Boston Keratoprosthesis type 1 (KPro), including risk factors and protective factors against glaucoma development.
CHUM – Hôpital Notre-Dame, Montreal, Canada
Retrospective case series of 137 consecutive eyes of 118 patients with KPro implantation between October 2008 and March 2017, with at least 6 months of follow-up. Of those, 118 eyes of 118 patients were analyzed to account for inter-eye correlation. Patients without glaucoma were compared to those diagnosed with glaucoma, which included treatment with intraocular pressure (IOP)-lowering medication or glaucoma surgery. The primary outcomes were preoperative diagnosis, glaucoma onset, best-corrected visual acuity (BCVA) and postoperative complications. Demographics, IOP and cup-to-disc ratio collected during follow-up were also recorded. Descriptive statistics and incidence rates were used to compare the outcome variables.
Mean age at surgery was 60.7±16.7 years, with mean follow-up of 6.9±3.2 years. The most common preoperative diagnosis for KPro surgery was pseudophakic bullous keratopathy (n=23, 19%). Of the 118 eyes, 17 (14%) did not have glaucoma. 74 (73%) of the 101 eyes with glaucoma had glaucoma prior to surgery. Post-KPro glaucoma incidence was 3.3 cases per 100 eye-years, with average onset at 2.2±2.3 years after surgery. Patients without final outcome of glaucoma were younger (P=0.042) and of male gender (P=0.035). Mean final LogMAR BCVA of the cohort was 1.5±0.8, with no difference between eyes with and without glaucoma (P≥0.05).
Glaucoma is a common complication following KPro implantation. Younger and male patients appear at decreased risk for glaucoma. Non-glaucomatous eyes do not achieve better final BCVA. Other postoperative complications should be carefully managed to avoid loss of BCVA and KPro extrusion.