An increase in microvasculature dropout may be linked to progressive retinal nerve fiber layer (RNFL) thinning in patients with primary open-angle glaucoma (POAG), a study in JAMA Ophthalmology reports.

Since parapapillary choroidal microvasculature dropout is considered a manifestation of glaucomatous damage, Korean researchers sought to determine whether it changed over time and understand its potential connection to RNFL thinning.

The case series, conducted at a tertiary referral center, included 68 patients with POAG who exhibited parapapillary choroidal microvasculature dropout. The patients were enrolled in the Investigating Glaucoma Progression Study from 2016 to 2018, and the study included masked observers who were unaware of the participants’ clinical characteristics for measurements.

Optical coherence tomography angiography (OCT-A) images were obtained twice at least two years apart, during which the RNFL thickness was measured at least four times in serial OCT exams. The microvasculature dropout area was measured in the OCT-A images at baseline and the final follow-up.

Among the 68 eyes, 32.4% showed increases in the microvasculature dropout area during 2.5 years of follow-up. Additionally, researchers reported faster global RNFL thinning was associated with a larger increase in the microvasculature dropout area.