Japanese researchers recently investigated the conjunctival and intrascleral vasculatures in glaucomatous eyes using anterior segment optical coherence tomography angiography (AS-OCTA) and assessed the factors contributing to the vessel density in the images. They found AS-OCTA images may be useful for objectively assessing conjunctival hyperemia and helpful for understanding the pathophysiology of post-trabecular aqueous humor outflow. 

This prospective, cross-sectional study evaluated 34 patients with primary open-angle glaucoma and 20 healthy subjects. The team obtained AS-OCTA images of the corneal limbus at the nasal and temporal quadrants and measured vessel densities in the superficial and deep layers. They then compared the vessel density between healthy and glaucomatous eyes and analyzed the association of the vessel density with possible confounding factors.

The study authors found that vessel density was not significantly different between healthy eyes and eyes with glaucoma. They note a significant association between superficial vessel density and both the use of a prostaglandin analog and nasal location in eyes with glaucoma. They add that deep vessel density was significantly smaller with advancing age in healthy eyes and greater with higher intraocular pressure in eyes with treated glaucoma.

Akagi T, Uji A, Okamoto Y, et a. Anterior segment optical coherence tomography angiography imaging of conjunctiva and intrasclera in treated primary open-angle glaucoma. Am J Ophthalmol. May 16, 2019. [Epub ahead of print].