Optical Coherence Tomography Angiography in Patients With the Boston Keratoprosthesis Type 1

To report on optical coherence tomography angiography (OCTA) in patients with a type 1 Boston keratoprosthesis (KPro) and determine its feasibility through assessment of imaging artifacts.

KPro and non-KPro subjects were matched for age, gender, and glaucoma diagnosis. OCTA images of the peripapillary optic nerve were obtained, reviewed by 2 readers masked to the diagnosis for artifacts and usability, and used for microvascular measurements.

KPro subjects (n = 18) had worse visual acuity than non-KPro (n = 36) subjects (LogMAR mean ± standard deviation 0.36 ± 0.30 vs. 0.07 ± 0.11, P < 0.001) and a greater proportion were monocular (56% vs. 3%, P < 0.001). OCTA from KPro eyes had more artifacts per scan than images from non-KPro eyes (4 ± 2 vs. 2 ± 2, P < 0.001). About 33% of KPro images were useable based on having image quality score above 40 and artifact in less than 10% of the peripapillary region. Worse visual acuity (odds ratio [OR] 0.01, 95% confidence interval [CI] 2 x 10 -4 -0.30, P = 0.02) and KPro (OR 0.19, 95% CI 0.05-0.63, P = 0.008) were associated with lowered likelihood of usability. Useable OCTA from 3 KPro eyes with glaucoma demonstrated microvascular defects in the inferior peripapillary region and lower vessel density and flow compared with 3 KPro eyes without glaucoma.

This is the first study assessing OCTA in KPro patients and identified a higher incidence of artifacts that may be associated with the KPro optic. About 33% of KPro images were useable for microvascular measurements, supporting further OCTA research in this population to assess vascular pathology of glaucoma.