Bruch’s membrane opening detection in healthy and glaucoma eyes with and without high myopia in an American and Korean population

Abstract

Purpose : To assess the proportions of automatic, manually corrected and indiscernible Bruch’s membrane openings (BMO) in eyes with and without high myopia and to investigate factors associated with indiscernible BMOs.

Methods : Glaucoma patients and healthy subjects from the Diagnostic Innovations in Glaucoma Study (DIGS) and Korean clinic population were included. Healthy and glaucoma eyes were classified into 2 groups by axial length (AL); no high myopia (AL <26mm) and high myopia (AL ≥26mm). Spectralis optic nerve head (ONH) scans containing 24 radial B-scans were utilized to automatically detect the BMO. All radial scans were reviewed by a trained operator and BMO placement manually corrected as needed. BMO was recorded as discernible or indiscernible and whether a seconder operator was needed to assist. Linear and logistic generalized estimating equations (GEE) were used to compare eye characteristics between groups.

Results : 143 healthy eyes (76 subjects) and 344 glaucoma eyes (224) were included. 28 (19.6%) and 42 eyes (12.2%) in the healthy and glaucoma group were high myopes. In healthy eyes with and without high myopia, 10.7% and 1.7% had indiscernible BMOs, 28.6% and 11.3% were corrected, and 60.7% and 87.0% were automatically segmented (respectively, p=0.03). In glaucoma eyes with and without high myopia, 7.1% and 3.0% had indiscernible BMOs, 45.2% and 37.4% were corrected, and 47.6% and 59.6% were automatically segmented (respectively, p=0.23). In eyes with high myopia, a second operator was required in 17.9% of the healthy and 11.9% of the glaucoma eyes. The proportion of high myopes was significantly higher among eyes with indiscernible BMOs (6/17, 35.3%) compared to eyes with corrected (27/126, 17.6%) and automatic BMOs (37/280, 11.7%) (p=0.05). BMO tilt was significantly higher in corrected and indiscernible BMOs (p=0.02) and OCT scans were more often decentered in eyes with indiscernible BMOs (p<0.01). Proportions of corrected and indiscernible BMOs were also significantly higher in healthy and glaucoma Korean eyes with high myopia compared to eyes without high myopia.

Conclusions : High axial myopia was associated with indiscernible BMOs, which may affect the diagnostic value of BMO-MRW for glaucoma assessment in highly myopic eyes.

This is a 2020 Imaging in the Eye Conference abstract.