Abstract
Purpose: :
To measure choroidal thickness in normal eyes and in patients with normal-tension glaucoma (NTG) using enhanced depth imaging (EDI) optical coherence tomography (OCT) and evaluate the association between choroidal thickness and progression of visual field damage.
Methods: :
A total of 62 eyes of 62 normal subjects and 45 eyes of 45 NTG patients were examined. The choroidal thickness was measured in images obtained by positioning a spectral-domain OCT. The choroid was measured from the outer border of the retinal pigment epithelium to the inner scleral border at the fovea and 3 mm nasal and temporal from the fovea. In the separate study, both eyes of the patients with NTG were included in the analyses. Visual fields were measured with automated perimetry. Changes in mean deviation (MD) per year (dB/year), that is, MD slope, were calculated.
Results: :
Compared to normal subjects, the choroidal thickness was significantly thinner in eyes with NTG at the fovea (P = 0.045) and at 3 mm nasal from the fovea (P = 0.038). Standard visual field testing was performed more than five times each in 61 eyes of 32 patients with NTG. There was a significant correlation between the choroidal thickness at 3 mm nasal from the fovea and the MD slope (Pearson r = 0.424; P < 0.01).
Conclusions: :
The decrease in the thickness of the choroid at 3 mm nasal from the fovea in eyes with NTG may be associated with progressive visual field loss. Thus, choroidal abnormalities may play a role in the pathogenesis of NTG.
Keywords: choroid • visual fields • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)