Structural and Functional Evaluation of Glaucomatous Neurodegeneration from Eye to Visual Cortex using 1.5T MR Imaging: A Pilot Study

Aim: Glaucoma is an optic neuropathy and glaucomateus damage proceeds from retinal ganglion cells to brain. A better understanding of retrobulbar damage will enable us to develop more efficient strategies and a more accurate understanding of glaucoma. We evaluated retrobulbar glaucomatous damage with favorable techniques for 1.5T MR imaging. Material and methods: Five glaucoma cases and one healthy subject are included. Diffusion tensor MR imaging and functional MR images were taken with 1.5T MR. Correlation of optic nerve and corpus geniculatum laterale diffusion tensor MR parameters with eye findings were statistically evaluated. Results: Optic nerve damage and cortical hypofunction were shown with diffusion tensor MR and functional MR imaging, respectively. Correlations of the apparent diffusion coefficient with mean deviation, pattern standard deviation, retinal nerve fiber layer thickness in distal optic nerve and fractional anisotropy with ganglion cell counting in proximal optic nerves and correlations of retinal nerve fiber layer thickness with axial diffusivities in both ipsilateral and contralateral corpus geniculatum laterales and with fractional anisotropy in ipsilateral corpus geniculatum laterale were statistically significant. Conclusion: The eye-brain connection in glaucoma can be evaluated with routine clinical instruments. Our results also revealed the eye-to-visual-pathway integrity of glaucomatous neurodegeneration, which must be verified in larger series.