Analyses of shape of eyes and structure of optic nerves in eyes with tilted disc syndrome by swept-source optical coherence tomography and three-dimensional magnetic resonance imaging

PurposeTo evaluate the deeper structures of the optic nerve and to analyze the shape of eyes with tilted disc syndrome (TDS) by swept-source optical coherence tomography (OCT) and three-dimensional magnetic resonance imaging (3D MRI).MethodsThe medical records of 54 eyes of 36 patients with TDS were reviewed. The patients with TDS and high myopia were analyzed separately from those without high myopia. All the eyes were examined with a swept-source OCT, and 22 of the eyes were examined by 3D MRI.ResultsA total of 38 eyes of 29 patients were highly myopic and 16 eyes of 15 patients were not highly myopic. The representative OCT findings of the optic disc were: a sloping of the lamina cribrosa posteriorly from the upper part to the lower part, a protrusion of the upper edge of Bruch's membrane, and choroid. The distance and the depth of the most protruded point from the fovea were significantly greater in the eyes with non-highly myopic TDS than those with highly myopic TDS. In the 3D MRI, the lower part of the posterior segment was protruded outward, and the optic nerves attached at the upper nasal edge of the protrusion.ConclusionsThe abnormalities detected by swept-source OCT and 3D MRI analyses indicate the possibility that the essential pathology of TDS is a deformity of the inferior globe below the optic nerve, and the positional relation between the fovea and the inferior protrusion determines the degree of myopia.