Tilted optic discs: The Beijing Eye Study.

PURPOSE: To determine the prevalence of tilted optic discs and their associations with ocular and general parameters. METHODS: The Beijing Eye Study included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. The present investigation consisted of 4324 (97.4%) subjects for whom readable fundus photographs of at least one eye were available. The main outcome parameter was the presence of tilted optic discs defined as small discs with an oblique orientation and oval disc shape without signs of pathology in eyes without high myopia (defined as >-8 D). RESULTS: Tilted optic discs were detected in 31 eyes (0.36; 95% confidence interval: 0.23, 0.49%) of 23 patients (16 women). Tilted discs were associated with myopia (-6.59+/-0.68 D vs -0.60+/-0.02 D, P<0.001), astigmatism (1.55+/-0.24 D vs 0.59+/-0.01 D, P<0.001), lower best corrected visual acuity (P<0.001), visual field defects (P<0.001), and small optic disc area (P<0.001). CONCLUSIONS: Tilted optic discs are present in about four out of 1000 eyes of adult Chinese in Northern China. They are associated with medium myopia, astigmatism, decreased visual acuity, and visual field defects.