Glaucoma has a greater effect on perfused capillary density than myopia

Using OCT angiography, investigators measured the peripapillary perfused capillary density (PCD) in patients with myopia and open-angle glaucoma.

Study design

The study cohort was divided into the following groups:

• 87 patients with both myopia and glaucoma
• 17 myopic patients without glaucoma
• 93 glaucoma patients without myopia

Fifty-one healthy individuals served as controls. All participants were at least 20 years old with a BCVA 20/40 or greater. Myopia was defined as spherical equivalent of -3 D or more.

Researchers conducted a comprehensive ophthalmic examination and OCT angiography for each patient.

Outcomes

Average global PCD was significantly higher in the control group (41) than the myopia-only group (38), glaucoma-only group (31) or myopic-glaucoma group (28). Investigators found no associations between glaucoma and myopia after adjusting for age, axial length and disease stage.

Limitations

Shortcomings include potential errors in capillary segmentation in eyes with high myopia. The number of subjects per treatment arm was small and patients were not well matched. The study lacked longitudinal data.

Clinical significance

This is an important study demonstrating that structural OCT has limited value in evaluating patients with myopia. The findings show that functional capillary density could serve as a potential marker for glaucoma.