Choroidal thickness measurement in highly myopic eyes using SD-OCT.

BACKGROUND AND OBJECTIVE: To measure macular choroidal thickness (CT) using spectral-domain optical coherence tomography (OCT) and to investigate the correlation between CT and age, degree of myopia, and history of macular choroidal neovascularization (CNV). PATIENTS AND METHODS: A cross-sectional study included 187 highly myopic eyes of 187 patients examined between January and December 2010. The choroid was imaged with spectral-domain OCT by changing the reference position from the vitreous to the choroid. CT was measured from the outer border of the hyperreflective line corresponding to the retinal pigment epithelium to the inner scleral border. RESULTS: The mean age was 47.21 ± 14.24 years, the mean spherical equivalent refractive error was -13.66 ± 5.77, and the mean subfoveal CT was 100.71 ± 59.98 µm. CT was correlated negatively with age (P < 10(-3)) and refractive error (P < 10(-3)). Forty-two eyes had a history of CNV, the mean CT was 55.45 ± 24.46 µm, and this was significantly thinner than in eyes without CNV (P < 10(-3)). CONCLUSION: In highly myopic eyes, the choroid is thin and undergoes further attenuation with age and increasing myopia. In addition, these findings suggest that the choroid may play a role in the pathogenesis of CNV.