Parafoveal vessel changes in primary open-angle glaucoma and normal-tension glaucoma using optical coherence tomography angiography

Abstract

Purpose

To evaluate parafoveal and peripapillary perfusion in healthy, glaucoma suspect, normal-tension glaucoma, and primary open-angle glaucoma subjects.

Patients and methods

This was a retrospective cross-sectional study with optical coherence tomography angiography imaging with RTVue XR Avanti (Optovue, Inc., Fremont, CA) of 56 eyes (14 healthy, 14 glaucoma suspect, 16 normal-tension glaucoma, and 12 primary open-angle glaucoma) at a tertiary academic referral center. Parafoveal and peripapillary superficial vessel density and parafoveal superficial retinal thickness were the main parameters of interest. Area under receiver operating characteristic curves were calculated.

Results

There were significant decreases in parafoveal superficial vessel density in primary open-angle (40.06±4.54%, P<0.001) and normal-tension glaucoma (42.82±5.16%, P=0.010) but not suspect eyes (45.72±4.37%, P=0.916) compared to healthy eyes (48.10±2.82%). Similarly, decreases were observed in parafoveal inner retinal thickness in primary open-angle (83.19±14.29 μm, P<0.001) and normal-tension glaucoma eyes (94.97±12.44 μm, P=0.035), but not suspect eyes (99.93±9.00 μm, P=0.648), compared to healthy controls (107.00±9.55 μm). Only primary open-angle glaucoma eyes displayed significant changes in peripapillary vessel density (37.63±7.19%) compared to healthy controls (49.12±2.80%, P<0.001). Further statistical adjustment for sex and age revealed a significant decrease in parafoveal vessel density in suspects relative to controls (P=0.039). Diagnostic accuracy of parafoveal vessel density was high with an area under the curve of 0.833±0.073 for normal-tension glaucoma and 0.946±0.049 for primary open-angle glaucoma.

Conclusion

Parafoveal vessel density was significantly reduced in glaucomatous eyes, with good diagnostic accuracy. These findings provide further evidence that these changes may be useful in the diagnosis and monitoring of disease in glaucoma patients.

Keywords:

• macular vessel density
• high-tension glaucoma
• low-tension glaucoma
• retinal imaging

Abbreviations

VD, vessel density; IOP, intraocular pressure; OCTA, optical coherence tomography angiography; NTG, normal-tension glaucoma; POAG, primary open-angle glaucoma; IPL, inner plexiform layer; ILM, inner limiting membrane; RNFL, retinal nerve fiber layer; MD, mean deviation; ROC, receiver operating characteristic; AUC, area under the receiver operating characteristic curve.

Ethics approval and informed consent

Written informed consent was obtained from all patients, and Institutional Review Board (IRB)/Ethics Committee approval was obtained from Northwestern University. This study was conducted in compliance with the Health Insurance Portability and Accountability Act of 1996 and the tenets of the Declaration of Helsinki.

Consent for publication

Written informed consent for publication was obtained from all patients.

Data availability

Data supporting the results reported in the manuscript can be obtained by contacting the corresponding author.

Acknowledgment

We would like to acknowledge Research to Prevent Blindness (New York, NY) which provided an unrestricted grant to Northwestern University. We would also like to acknowledge OptoVue, Inc which provided research instrument support to Northwestern University.

This work was supported by an unrestricted grant to Northwestern University from Research to Prevent Blindness (New York, NY). OptoVue, Inc provided research instrument support to Northwestern University. The sponsor or funding organizations had no role in the design or conduct of this research or the decision to submit for publication.

Author contributions

All authors contributed to data analysis, drafting, or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.