Wedge Defects on Optical Coherence Tomography Angiography of the Peripapillary Retina in Glaucoma: Prevalence and Associated Clinical Factors

Abstract

Précis: Among subjects with glaucoma, wedge-shaped defects on optical coherence tomography angiography (OCTA) were associated with disc hemorrhages (DH), paracentral visual field (VF) defects, increased cup-to-disc ratio (CDR), and thinner retinal nerve fiber layer (RNFL).Purpose: To examine determinants of wedge defects on peripapillary OCTA in glaucoma. Materials and Methods:A total of 278 eyes of 186 subjects with mild to severe primary open-angle glaucoma underwent 6×6 spectraldomain OCTA imaging of the superficial peripapillary retina from 2016 to 2020 at an academic practice. Wedge defects were defined as focal microvasculature loss that extends outward from the optic nerve in an arcuate, wedge shape. Logistic regression models controlling for intereye correlation identified variables significantly associated with wedge defects. Eyes with profound microvasculature loss in both hemispheres were excluded. Candidate variables included: age, sex, race or ethnicity, diabetes, hypertension, follow-up duration, baseline untreated intraocular pressure, intraocular pressure at time of imaging, DH history, paracentral VF defects, CDR, central corneal thickness, spherical equivalent, VF mean deviation, RNFL thickness, and glaucoma stage.Results: Of 278 eyes, 126 (45.3%) had wedge defects in at least 1 hemisphere. In our multivariable logistic regression model, wedge defects were associated with DH history [odds ratio (

Quantification of localised vascular wedge‐shaped defects in glaucoma

“…Similarly, Ichiyama et al observed concordant VF loss with localised reduced vessel density 7 . LeTran et al specified paracentral defects as being associated with vascular wedge defects, however, it is unclear whether other patterns of field loss were not reported or not present 11 . The current study includes a high proportion of preperimetric and early‐stage POAG eyes with only minor VF loss.…”

“…Reduced corneal thickness is typically associated with glaucoma progression, 40 which supports the reduced thickness in the eyes with vascular wedges in cohort one which were more likely to have glaucoma progression. Yet, LeTran et al observed higher corneal thickness in eyes with vascular wedge defects compared with those with non‐specific defects or profound loss, 11 supporting the trend in cohort two. Future studies are needed with larger cohorts to determine the true relationship between wedge defects and corneal thickness.…”

“…History of DH was determined to be more likely in eyes with vascular wedge defects than in eyes without. Similarly, LeTran observed a strong relationship between DH history and vascular wedge defects, with 65% of POAG eyes with both vascular wedges and DH having hemispheric concordance of these events 11 . Lee et al observed increased choroidal vessel density loss in localised regions which spatially corresponded to DH location in POAG eyes 22 .…”

“…Previous studies have commented on localised vessel density reductions around the nerve head and peripapillary which correspond with RNFL bundle defects in primary open angle glaucoma (POAG) 7–11 . These vascular wedge defects are visible with en face optical coherence tomography angiography (OCTA) imaging.…”

“…5,6 Previous studies have commented on localised vessel density reductions around the nerve head and peripapillary which correspond with RNFL bundle defects in primary open angle glaucoma (POAG). [7][8][9][10][11] These vascular wedge defects are visible with en face optical coherence tomography angiography (OCTA) imaging. OCTA is a non-invasive imaging technique which contrasts stable light intensity with the dynamic motion of blood flow, to enable visualisation of the retinal microvasculature.…”