Baseline choroidal microvasculature dropout as a predictor of rapid global structural loss in open-angle glaucoma

Abstract

This study included 102 open-angle glaucoma (OAG) eyes with or without a localized choroidal microvasculature dropout (CMvD) at the inferior hemiretina, matched for age (≤ 10 years), axial length (≤ 1 mm), and visual field severity (≤ 1dB), and with a minimum 2-year follow-up. Serial thickness [circumpapillary retinal nerve fiber layer (cpRNFLT) and macular ganglion cell-inner plexiform layer thickness (mGCIPLT)], and vessel density (VD) [circumpapillary (cpVD) and macular VD (mVD)] parameters were obtained. The rate of change in each parameter at both the superior (CMvD-unaffected) and inferior (CMvD-affected) hemiretina were compared between matched eyes with (CMvD+) and without CMvD (CMvD-). Clinical factors associated with the rate of change in each parameter both globally and at the CMvD-unaffected hemiretina were also evaluated. CMvD + eyes showed significantly faster rates of VD and thickness loss at both the CMvD-affected and -unaffected hemiretina. In addition, CMvD was significantly associated with rapid loss of both VD and thickness parameters globally and at the CMvD-unaffected superior hemiretina. In conclusion, OAG eyes with CMvD show significantly faster rates of VD and thickness loss at both the CMvD-affected and unaffected hemiretina. A localized CMvD is an independent predictor of globally rapid structural loss in OAG eyes.

Keywords: Choroidal microvasculature dropout; Glaucoma; Optical coherence tomography angiography; Progression.

Fig. 1

An example of open-angle glaucoma eye with a single choroidal microvasculature dropout (CMvD) within the beta zone parapapillary atrophy (β-PPA) at the inferior hemiretina (a, b) and visual field defect confined within the superior hemifield (c). Boundaries of the optic disc (green dashed line), β-PPA (yellow dashed line) and CMvD (red outline) were delineated on the En face choroidal layer image of optical coherence tomography angiography (OCT-A) (b). En face OCT-A images show circumpapillary (d) and macular vessel density (e) maps. The circumpapillary retinal nerve fiber (f) and macular ganglion cell-inner plexiform layer thickness (g) are measured by OCT scan. The pink and gray colors denote the CMvD-affected and -unaffected hemiretina, respectively.

Fig. 2

72 year-old female patient presented with a single choroidal microvasculature dropout (CMvD) within the β-parapapillary atrophy (β-PPA) at the inferior hemiretina (a, b) and visual field defect confined to the superior hemifield (c) on her left eye. Green and yellow dashed line indicate the margin of optic nerve head and β-PPA, respectively (b). The red outline indicates the CMvD (b). She showed progressive loss of circumpapillary vessel density (d), macular vessel density (e) and circumpapillary retinal nerve fiber layer thickness (f) and macular ganglion cell-inner plexiform layer thickness (g) during a 3.4-year follow-up at both superior (CMvD-unaffected) and inferior (CMvD-affected) hemiretina.

Fig. 3

65-year-old female patient presented without a microvasculature dropout (CMvD) within (a, b) and visual field defect confined to the superior hemifield (c) on her left eye. Green and yellow dashed line indicate the margin of optic nerve head and β-parapapillary atrophy, respectively (b). She showed stable vessel density and thickness parameters over a 3.0-year follow-up at both the superior and interior hemiretina (d–g).