Longitudinal Measurement of Optic Disc Vessel Density to Detect Glaucoma Progression in High Myopia.

Abstract

Purpose: To investigate the relationship between optic disc vessel density (ODVD) reduction and visual field (VF) progression in highly myopic glaucomatous eyes.

Design: Retrospective, observational case series.

Participants: One hundred eighteen primary open-angle glaucoma (POAG) eyes with high myopia (axial length [AXL] ≥ 26.5 mm or spherical equivalent [SE] ≤ -6 diopters [D]) and 118 age-matched and VF severity-matched POAG eyes without high myopia (AXL < 26.0 mm and SE > -6 D).

Methods: All participants underwent 5 or more consecutive VF tests, OCT, and OCT angiography (OCTA) over 4.1 years. Optic disc vessel density was calculated as the pixel ratio of vessels in the temporal optic disc area on en face OCTA images.

Main outcome measures: The association between VF progression and the rate of ODVD change after adjusting for possible influencing factors, including retinal nerve fiber layer (RNFL) thinning rate.

Results: In highly myopic eyes, those with VF progression (n = 41) exhibited a significantly faster rate of global ODVD reduction compared with those without progression (n = 77; -3.96 ± 2.15%/year vs. -1.68 ± 2.37%/year; P < 0.001). In highly myopic eyes, younger age (odds ratio [OR], 1.09 per 1 year younger; P = 0.002), a higher prevalence of optic disc hemorrhage (OR, 6.76; P = 0.002), thinner RFNL at baseline (OR, 1.04 per 1 μm thinner; P = 0.024), and a faster rate of global ODVD change (OR, 1.63 per 1%/year faster; P < 0.001) were associated with VF progression in multivariable regression. Conversely, the rate of average RNFL thinning (P > 0.05) showed no significant association with VF progression in highly myopic eyes. For eyes without high myopia, significant associations with VF progression were found for both a faster rate of average RNFL thinning (OR, 2.43 per 1 μm/year faster; P = 0.006) and ODVD change (OR, 1.42 per 1%/year faster; P = 0.004) in the multivariable regression.

Conclusions: In highly myopic glaucomatous eyes, progressive ODVD reduction was associated with VF progression, whereas RNFL thinning was not. This indicates that monitoring of optic disc microvasculature may be useful for detecting glaucoma progression in high myopia.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.