Choroidal microvascular dropout may be much higher in patients with primary open-angle glaucoma (POAG) than in those with primary angle-closure (PACG) or pseudoexfoliation glaucoma (PXG) in the early stages, but there appears to be no differences between the groups in advanced stages, a recent study in the Journal of Glaucoma suggests.

Using OCT angiography, researchers from Korea imaged the choroid of 186 eyes of 186 patients matched by age and visual field mean deviation (MD). The study compared the choroidal microvascular dropout among glaucoma types in early and moderate-to-advanced disease, as divided by visual field MD. Additionally, the researchers looked for associations between glaucoma type and the presence of choroidal microvascular dropout.

In the early disease stages, the prevalence of choroidal microvascular dropout was significantly different between glaucoma types, and highest in POAG at 46.3%, followed by PXG at 25% and PACG at 7.5%. However, its prevalence didn’t differ significantly between the types in moderate-to-advanced disease: POAG, 81%; PXG, 68.2%; and PACG, 59.1%. 

 Additionally, after adjusting for age, gender, peripapillary atrophy/disc ratio and glaucoma severity, the choroidal microvascular dropout odds ratio was 7.5 times greater in POAG than in PACG.

The study’s findings suggest a role for ischemic injury in the pathogenesis of POAG, the researchers noted.