Juxtapapillary choroid is thinner in normal-tension glaucoma than in healthy eyes

Abstract

Purpose: To measure the juxtapapillary choroidal thickness in eyes with normal-tension glaucoma (NTG) and to compare it with healthy eyes. Methods: Twelve radial B-scan images of the optic nerve head (ONH) were obtained from 96 patients with NTG and 48 healthy subjects matched by age using swept-source (SS) optical coherence tomography (OCT). The juxtapapillary choroidal thickness was defined as the average choroidal thickness within 500 μm from the border tissue of Elschnig. Choroidal thinning in patients with NTG was assessed by calculating the relative choroidal thickness, defined as the ratio of the measured juxtapapillary choroidal thickness in each meridian to the corresponding value in age-matched healthy controls. Retinal nerve fibre layer (RNFL) damage as reflected by circumpapillary RNFL thickness (measured using spectral-domain OCT) was also assessed. Results: The juxtapapillary choroid was significantly thinner in NTG eyes than in healthy control eyes in the inferotemporal and superotemporal sectors. The relative choroidal thinning was topographically associated with the hemispheric location of dominant RNFL damage. The average juxtapapillary choroidal thickness was not associated with either the global RNFL thickness or the visual field mean deviation. Age and untreated intraocular pressure were significantly associated with the juxtapapillary choroidal thickness in NTG eyes in both univariate and multivariate analyses (all p < 0.05). Conclusions: Decreased microvascular circulation in the ONH as a result of juxtapapillary choroidal thinning could be an important part of the pathogenesis of optic nerve damage in NTG.