Sub-foveal choroidal thickness in both eyes of patients with unilateral primary open-angle glaucoma and related influencing factors

Abstract

Objective: To investigate and compare the sub-foveal choroidal thickness (SFCT) in both eyes of patients with unilateral primary open-angle glaucoma (POAG) and healthy controls. Methods: Cross-sectional study. Patients with unilateral POAG and healthy controls were recruited from September 2018 to September 2019 in the Beijing Tongren Hospital. All subjects underwent enhanced depth imaging optical coherence tomography. The SFCT was measured at the fovea, and at 500 μm, 1 000 μm and 2 000 μm nasal and temporal to the fovea. Paired t test was conducted to compare the choroidal thickness between affected POAG eyes and unaffected fellow eyes. Analysis of covariance was conducted to compare the choroidal thicknesses between POAG eyes and controls. Multiple regression analysis determined the association between choroidal thickness and age, gender, spherical equivalent and mean deviation. Results: Seventy-five patients with unilateral POAG (mean age, 46 years; 48 males, 27 females) and 61 healthy controls (mean age, 44 years; 34 males, 27 females) were included in this study. The SFCT of POAG eyes was (244.41±83.18) μm, which was not significantly different from their unaffected fellow eyes [(254.28±88.92) μm, P>0.05] and controls (right eyes) [(272.98±55.87) μm, P>0.05]. Choroidal thickness at 2 000 μm nasal to the fovea was significantly decreased in the glaucomatous eyes compared with the unaffected fellow eyes [(167.84±70.44) vs. (188.84±89.06) μm, t=-3.55; P<0.01]. There were no significant differences among the glaucomatous eyes, unaffected fellow eyes and healthy controls in choroidal thickness at 500 μm and 1 000 μm nasal and temporal to the fovea, as well as at 2 000 μm temporal to the fovea (all P>0.05). The SFCT of POAG eyes was associated with mean deviation (β=14.66, P<0.05) and spherical equivalent (β=14.95, P<0.01) but not with age and gender (both P>0.05). Conclusions: The SFCT of affected eyes in patients with unilateral POAG has no significant difference from unaffected fellow eyes and healthy controls. However, the choroidal thickness at 2 000 μm nasal to the fovea is thinner in the POAG eyes as compared with the fellow eyes. A thinner SFCT is correlated with the loss of visual field and a higher spherical equivalent in myopia. This may suggest a contributing role of the perfusion of the choroid in the pathogenesis of glaucoma. (Chin J Ophthalmol, 2021, 57: 194-200).