AIM: To evaluate the characteristic of choroidal thickness(CT)in highly myopic glaucoma eyes, and investigate the factors that affect the CT in various regions of the macula.

METHODS: Thirty-two highly myopic eyes of 18 patients with primary open angle glaucoma(POAG), 36 non-highly myopic eyes of 20 patients with POAG, and 33 non-glaucoma highly myopic eyes of 21 matched volunteers were enrolled. CT at subfoveal, and 1mm and 3mm nasal, temporal, superior, and inferior to the fovea was measured using enhanced depth imaging coherence tomography. Multiple linear regression analyses were performed to detect the effects of diagnosis, spherical equivalent(SE), age, intraocular pressure(IOP), central corneal thickness(CCT), and mean deviation(MD)of visual field defect on CT at all measured points.

RESULTS: The choroid of highly myopic glaucoma eyes was statistically thinner than non-highly myopic glaucoma eyes at various locations(all P<0.05), while there was no significant difference between highly myopic glaucoma and non-glaucoma high myopia eyes at all locations(all P>0.05). Multiple regression analysis showed that SE was the most influential factor on CT in all regions of the macula, and CT varied significantly with age in 3mm superior to fovea(S3CT), but not with diagnosis, MD of visual field defect, IOP, or CCT.

CONCLUSION: CT in highly myopic glaucoma is equivalent in comparison with non-glaucoma highly myopia, although it's thinner than that in glaucoma eyes without high myopia. This implies the lack of association between CT and progression of glaucomatous optic neuropathy.