Spatial positional relationship between macular superficial vessel density and ganglion cell-inner plexiform layer thickness in primary angle closure glaucoma

Yongdong Lin,Mingzhi Zhang,Anlin Zhang,Weihao Cai,Di Ma,Hongxi Wang,Shirong Chen

doi:10.1007/s10792-021-02005-7

Abstract

PurposeTo evaluate the spatial relationship between macular superficial vessel density (SVD) and macular ganglion cell-inner plexiform layer (GCIPL) thickness in primary angle closure glaucoma (PACG), and to investigate diagnostic abilities of macular SVD and foveal avascular zone (FAZ) parameters.MethodsThis was a cross-sectional study on 38 PACG patients (38 eyes) and 25 healthy subjects (25 eyes). Macular region was imaged using a 1050-nm-wavelength swept-source optical coherence tomography (OCT) angiography (OCTA) system (DRI OCT Triton, TOPCON). Vessel density of the macular region was quantified by ImageJ software. The peripapillary retinal nerve fiber layer (pRNFL) thicknesses and macular GCIPL thickness were obtained by swept-source OCT. Pearson correlation analysis was used to evaluate the spatial positional relationship between macular SVD and macular GCIPL thickness. At the same time, the correlation between macular SVD and pRNFL thickness was evaluated. Areas under the receiver operating characteristics curves (AUCs) of OCT, OCTA and FAZ measurement metrics were calculated to assess the diagnostic ability for glaucoma.ResultsMacular GCIPL thickness had a moderate correlation with the macular SVD in the inferonasal sector (r = 0.426, P = 0.008). In addition, there was a strong correlation between inferonasal sector of macular vessel density and 5,6,7,8 clock-hour regions of the pRNFL thicknesses (all r > 0.5). Inferoinferior sector of macular SVD and 6,7 clock-hour regions of pRNFL thicknesses also had strong correlation (all r > 0.5). The AUCs of macular SVD ranged between 0.61 (superonasal sector) and 0.76 (inferoinferior sector). The FAZ circularity index showed the highest diagnostic power (AUC = 0.94;95% CI, 0.85–0.99), followed by superotemporal sector of macular GCIPL thicknesses (0.93;95% CI,0.83–0.98).ConclusionsSector of macular SVD not only had a spatial positional correlation with corresponding macular GCIPL thickness, but also with clock-hour regional pRNFL thicknesses in PACG eyes. FAZ circulation index might be a useful diagnostic parameter.

Highlights

Primary angle closure glaucoma (PACG) is more likely to cause blindness than primary open-angle glaucoma (POAG), of which more than 80% are in Asia [1,2,3]
Except for SN sector, global and each regional macular superficial vessel density (SVD) of the glaucoma group were lower than that of the healthy group.We found that the greatest reduction of vessel density in glaucomatous eyes was the macular II sector
Our study found that the sector macular SVD in PACG was topographically related to corresponding ganglion cell-inner plexiform layer (GCIPL) thickness only in the IN sector

Summary

Introduction

Primary angle closure glaucoma (PACG) is more likely to cause blindness than primary open-angle glaucoma (POAG), of which more than 80% are in Asia [1,2,3]. The study of PACG by optical coherence tomography angiography (OCTA) showed that peripapillary vessel density decreased [4,5,6,7]. Studies on PACG using OCTA were mainly on the optic disk area, less on the macular region. Previous studies using OCTA found that macular vessel density decreased and showed fairly diagnostic power in PACG eyes [11, 12]. Perhaps the diagnostic ability of macular vessel density in the inferior area is higher. The diagnostic ability of macular vessel density in each sector remained unclear in PACG. Previous study reported that FAZ parameters in POAG had good diagnostic ability by using OCTA [17]. No studies investigated the FAZ’s diagnostic ability for PACG when compared with traditional optical coherence tomography (OCT) parameters

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