Superficial capillary plexus vascular densities are reduced in patients with primary open angle glaucoma

Abstract

Purpose : To investigate differences in macular vascular parameters in persons with primary open-angle glaucoma (OAG) and healthy controls, to evaluate their diagnostic abilities and to compare them with retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness.

Methods : In a prospective cross-sectional analysis, 56 OAG patients and 94 healthy controls underwent optical coherence tomography angiography (OCTA-Optovue) assessment of macular vessel density (VD%) in the superficial (SCP) and deep (DCP) capillary plexus in the parafovea and perifovea, the whole image, and each hemisphere [superior (SH) and inferior (IH)], and quadrant [superior (SQ), inferior (IQ), nasal (NQ), temporal (TQ)]. Foveal avascular zone (FAZ) area (mm²), perimeter (mm), and vessel density (FD); and retinal and choriocapillaris flow area (mm²) were determined. Patients were classified for functional severity based on the Glaucoma Staging System 2 (GSS2) of Brusini. ANCOVA comparisons were adjusted for age, and areas under the receiver operating characteristic curves (AUC) were calculated.

Results : Mean SCP VD was significantly lower in OAG patients compared to healthy controls in the whole image, parafovea and perifovea at a global, hemispheric and quadrant level (all p<0.001). No statistically significant differences were found between OAG patients and healthy controls for DCP VD, FAZ parameters and retinal and choriocapillaris flow area (p>0.05). SCP VD was significantly lower in OAG patients with increased functional disease severity (GSS2 stage 2 compared to stage 0) for the whole image (global, SH and IH) and perifovea (global, SH, IH, SQ, IQ, TQ) regions (p=0.014-0.038). The AUC of SCP VD whole image was significantly higher than the AUC of DCP VD, FAZ parameters and retinal and choriocapillaris flow area (p=0.001-0.018). The best performing macular OCTA biomarker (whole image SCP VD) was similar to the AUC of global RNFL (p=0.533) and GCC thickness (p=0.423), Figure 1.

Conclusions : Macular SCP VD is significantly lower in persons with OAG and exhibits progressive loss with increasing functional disease severity. SCP VD had the highest performance for the diagnosis of OAG among all OCTA-assessed macular vascular parameters and was statistically similar to RNFL and GCC thickness.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Receiver operating characteristic curves (AUC) of optical coherence tomography angiography derived parameters.