PERIPAPILLARY RETINAL NERVE FIBER LAYER (RNFL) VASCULAR MICROCIRCULATION USING OPTICAL COHERENCE TOMOGRAPHY BASED MICROANGIOGRAPHY TO DISCRIMINATE GLAUCOMA OR GLAUCOMA SUSPECT AND HEALTHY CONTROL PATIENTS.

Abstract

Purpose : To analyze peripapillary RNFL microcirculation between age- and sex-matched open-angle glaucoma (OAG), glaucoma suspect (GS) and healthy control (HC) patients using optical coherence tomography angiography.

Methods : Cross-sectional study involving 93 age- (+/- 3 years) and sex-matched patients divided in 3 groups: OAG group (31 patients), GS group (31 patients) and HC group (31 patients). One eye of each patient was randomly selected for analysis. All patients underwent a complete eye examination including intraocular pressure measurement, an evaluation of optic nerve head vertical cup disc ratio, gonioscopy and standard automated perimetry using Humphrey visual field test (HFA 720i, ZEISS, Dublin, CA). All patients were scanned using CIRRUS HD-OCT 5000 with AngioPlex OCT angiography (ZEISS, Dublin, CA) and peripapillary perfusion was evaluated within a field of view of 3-by-3 mm. Flow signals were generated from the Optical Micro Angiography (OMAG^C) dataset by detecting the differences in OCT signal between consecutive B-scans. The retinal nerve fiber layer (RNFL) was automatically segmented from the structural cube data and an enface angiography image of the RNFL layer was generated. Vessel area density and normalized flux index were calculated within an annulus (inner and outer diameters of 2.0 mm and 3.0 mm) centered at the optic disc. Area under the receiver operating curve (AUROC) analyses were used to evaluate the discrimination ability of flux index, vessel area density, and RNFL thickness (RNFLT) among groups.

Results : The mean age was 64.8+/-6.9 years and 51 patients were female (54.9%), When analyzing OAG and HC groups, highest AUROC was observed for RNFLT average (0.888) followed by flux index average (0.833) and vessel area density average (0.794). When analyzing GS and HC groups, the highest AUROC was observed for vessel area density average (0.725) followed by flux index average (0.713) and RNFLT average (0.712).

Conclusions : Peripapillary RNFL microcirculation parameters had good diagnostic performance to discriminate glaucoma and performed slightly better than RNFLT to discriminate glaucoma suspect patients. Prospective studies are required to determine whether impaired peripapillary RNFL microcirculation could be used as an early biomarker of glaucoma progression.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.