Horizontal and vertical optic disc rotation. The Beijing Eye Study.

PurposeTo measure the optic disc rotation around the vertical and horizontal disc axis and to evaluate associations with general and ocular parameters.DesignPopulation-based study.MethodsIn the Beijing Eye Study, 3468 participants (mean age:64.6±9.8 years; range:50-93 years) underwent an ophthalmological examination which included spectral-domain optical coherence tomography (OCT) with enhanced depth imaging. Using the OCT images, we determined the amount of the rotation of the optic disc (defined as Bruch´s membrane opening (BMO)) around the vertical axis and horizontal axis.ResultsOptic disc rotation measurements were available for 3037 (87.6%) individuals. In multivariate analysis, larger optic disc rotation around the vertical axis (range:-4.90° to 41.0°) was associated (regression coefficient r:0.27) with high axial myopia (axial length ≥26.5 mm) (PConclusionsVertical optic disc rotation was associated with highly myopic axial elongation, increased disc-fovea distance and development or enlargement of parapapillary, Bruch´s membrane free, gamma zone, while macular Bruch´s membrane length is not affected. Horizontal optic disc rotation was associated with inferior dislocation of the fovea, in addition to a thinner superior nasal RNFL and thicker inferior nasal RNFL. The latter association may be taken into account in the interpretation of RNFL thickness profiles.