Previous research has reported that individuals with myopia are 2.5 times more likely to have glaucoma than those without it.1 Looking into this association, a new study suggests glaucomatous eyes with highly myopic optic discs may have larger Bruch’s membrane opening (BMO) tilt and smaller peripapillary choroidal thickness (PCT).2 Still, the research team found the parameters weren’t tied to glaucoma severity based on visual field outcomes.2
Additionally, the multi-center research team stressed that caution should be exercised when using sectoral BMO tilt, BMO minimum rim width and RNFL thickness for glaucoma management decisions in myopic eyes, as the pattern varied with axial length.2
The study included a custom automated analysis of OCT images and enrolled 452 eyes of 277 glaucoma patients who were grouped into non (145 eyes), mild (214 eyes) and high axial length (AL) myopia defined as AL greater than 26mm (93 eyes).2
The researchers calculated the optic disc ovality, tilt and rotation angle of BMO and PCT using automated and deep learning strategies. Their key findings included:2
High myopic optic discs were more oval and had larger BMO tilt compared with mild and non-myopic discs.
Mean PCT was thinnest in high myopic eyes followed by mild and non-myopic eyes.
The three groups had similar BMO rotation angle, global RNFL thickness and BMO minimum rim width measurements.
In high myopic eyes, the temporal RNFL was thicker, while the supranasal BMO minimum rim width was thinner.
BMO tilt and PCT showed moderate associations with AL. On the other hand, temporal RNFL and nasal BMO minimum rim width exhibited a weak yet still significant association with AL.
Large BMO tilt angle and thin PCT were characteristics of highly myopic discs and were not linked to glaucoma severity.
This information can be used to inform the clinical management of glaucoma in myopic eyes and also contribute to the understanding of pathophysiology in the eyes of those with both ocular conditions.2
1. Marcus MW, de Vries MM, Junoy Montolio FG, et al. Myopia as a risk factor for open-angle glaucoma: a systematic review and meta-analysis. Ophthalmology. 2011;118(10):1989-94.
2. Rezapour J, Bowd C, Dohleman J, et al. The influence of axial myopia on optic disc characteristics of glaucoma eyes. Sci Rep. 2021;11(1):8854.