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 2016-2023 and 97 eyes (79 patients) from 2004-2009.

Development of de novo glaucoma and glaucoma progression were defined as an increase of cup-to-disc ratio (CDR) ≥0.2 from baseline to final follow-up, assessed by experienced KPro specialists and corroborated with optical coherence tomography (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 differed in final VA (LogMAR 1.59±1.20 vs. 1.10±0.82, p=0.002). Despite a higher prevalence of preexisting 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% 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 post-operative care for patients with keratoprosthesis.