A study based in Seoul, South Korea, has found that patients with age- and glaucoma severity-matched pseudoexfoliation and primary open-angle glaucoma (POAG) did not have significantly different circumpapillary vessel density or most superficial macular vessel density parameters.
The study used OCT angiography (OCT-A) to examine the circumpapillary, parafoveal and perifoveal vessel densities in 98 eyes from 98 patients (49 POAG, 49 pseudoexfoliation). After adjusting superficial and deep layer macular vessel densities for age, IOP, signal strength index, axial length and RNFL thickness, the two groups did not differ in any sector. In the peripapillary region, none of the vessel densities differed between groups both before and after adjustment.
The researchers did note that factors associated with reduced circumpapillary vessel density were different between the two groups. The vessel density in POAG eyes significantly correlated with visual field (VF) mean deviation and RNFL thickness, while IOP, VF mean deviation and RNFL thickness affected vessel density in pseudoexfoliation. The macular vessel density in the deep layer was associated with only signal strength index in both groups.
The study contends that reduced vessels in the eyes from the two diseases is mainly a secondary change originating from glaucomatous damage, rather than a primary pathological event. The researchers proposed that circumpapillary vessel density could be a potential biomarker for assessing glaucomatous damage in pseudoexfoliation eyes.
Since signal strength significantly affected macular deep layer vessel density, they also noted that the currently available OCT-A technology might not be adequate for evaluating deep layer circulation in pseudoexfoliation.
|Jo YH, Sung KR, Shin JW. Peripapillary and macular vessel density measurement by optical coherence tomography angiography in pseudoexfoliation and primary open-angle glaucoma. J Glaucoma. February 19, 2020. [Epub ahead of print].|