Are We Doing Better a Decade Later?: Glaucoma in Patients with Boston Keratoprosthesis Type 1

To compare glaucoma outcomes after Boston type 1 keratoprosthesis (KPro) implantation in a recent cohort with a previous cohort from a decade before.

Retrospective comparative cohort study.

Patients who underwent KPro surgery at Mass Eye and Ear: 67 eyes (64 patients) from 2016 to 2023 and 97 eyes (79 patients) from 2004 to 2009.

Development of de novo glaucoma and glaucoma progression were defined as an increase in cup-to-disc ratio (CDR) ≥0.2 from baseline to final follow-up, assessed by experienced KPro specialists and corroborated with OCT and Humphrey visual field (HVF) data when available.

Primary outcome was glaucoma progression within 4 years after KPro. Secondary outcomes were postoperative visual acuity (VA), intraocular pressure (IOP), and complications.

Mean follow-up was similar between the recent and previous cohorts (3.2 ± 1.2 vs. 3.4 ± 1.1 years, P = 0.43). Prior infection and failed corneal grafts were more common in the recent cohort (43% vs. 22%, P = 0.003; 67% vs. 33%, P < 0.001). Preoperative VA was similar (logarithm of the minimum angle of resolution [LogMAR] 1.77 ± 0.89 vs. 1.96 ± 0.53, P = 0.09) but recent and previous cohorts differed in final VA (LogMAR 1.59 ± 1.20 vs. 1.10 ± 0.82, P = 0.002). Despite a higher prevalence of pre-existing glaucoma (79% vs. 63%, P = 0.03), glaucoma progression was less frequent in the recent cohort (11% vs. 47%, P < 0.001), while de novo glaucoma rates were similar (P = 0.84). In the recent cohort, CDR-based assessments agreed with OCT and HVF findings in 78% and 89% of 21% of eyes, respectively. Notably, more patients in the recent cohort received glaucoma surgery prior to (40% vs. 18%, P = 0.001) or concurrently (12% vs. 2%, P = 0.01) with KPro surgery. The recent cohort had lower final IOP (13 ± 5 vs. 16 ± 6 mmHg, P < 0.001) and fewer eyes requiring ≥2 topical glaucoma medications (P = 0.005). Endophthalmitis occurred more frequently in the recent cohort (7% vs. 1%, P = 0.03), whereas other complications were similar (P ≥ 0.07).

Despite a greater baseline glaucoma burden, the recent cohort experienced lower rates of glaucoma progression and improved IOP control, likely reflecting earlier and more frequent surgical glaucoma interventions. Nonetheless, vision-threatening complications remain an ongoing challenge, emphasizing the need for continued effort to improve postoperative care for patients with keratoprosthesis.

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.