Peripapillary Microvascular Parameters in Unilateral Open-Angle Glaucoma Using the Optical Coherence Tomography-Angiography
Victor Ephraime V. Paulino, MD, DPBO
John Mark S. de Leon, MD, DPBO
Eye Institute, St. Luke’s Medical Center, Quezon City, Metro Manila, Philippines
Corresponding Author: Victor Ephraime V. Paulino, MD, DPBO
Clinic Address: Eye Institute, St. Luke’s Medical Center, #279 E. Rodriguez, Sr. Avenue, Quezon City, Philippines 1112
Contact Number: +632 8-7230101 ext 4100/5548
Email Address: rempaulino@gmail.com
Disclosure: The authors declare no conflict of interest. No funding was received for the conduct of this study.
ABSTRACT
Objective: This study compared the peripapillary retinal nerve fiber layer (pRNFL) microangiographic properties [vessel area density (VAD) and blood flux index (BFI)] of unilateral open-angle glaucomatous eyes to contralateral eyes-at-risk, and to eyes of healthy age- and sex-matched subjects.
Methods: This was a single-center, case-control study of Filipinos diagnosed with unilateral primary open-angle glaucoma (POAG) or normal-tension glaucoma (NTG). Mean overall and quadrantal VAD and BFI of the three groups were measured with optical coherence tomography- angiography (OCT-A). Area under the receiver operating characteristic (AROC) was used to measure diagnostic ability.
Results: Twenty-two (22) glaucomatous subjects (15 POAG and 7 NTG eyes), 22 contralateral eyes-at-risk, and 22 normal eyes from age- and sex-matched control subjects completed the study. Eyes with glaucoma showed lower mean overall VAD (40%) and BFI (0.37) compared to eyes-at-risk (44.4% and 0.42, respectively; p <0.001) and control eyes (45.6% and 0.44, respectively; p <0.001). Mean VAD and BFI values of eyes-at-risk and control groups did not significantly differ from each other. Overall pRNFL thickness showed highest diagnostic accuracy for glaucoma (AROC = 0.97), followed by VAD (0.94), and BFI (0.88) (p=0.46).
Conclusion: VAD and BFI were significantly diminished in unilateral open-angle glaucoma, suggesting that the utility of OCT-A in the detection of glaucoma is comparable to pRNFL thickness.
Keywords: OCT-angiography, peripapillary microcirculation, blood flux index, vessel area density, unilateral glaucoma