Stroke and Neurological Disorders

Glaucoma represents a group of neurodegenerative diseases characterized by structural damage to the optic nerve and the slow, progressive death of retinal ganglion cells. On the other hand, impacts of glaucoma on the optic nerve (ON), corpus geniculatum lateral (CGL) and visual cortex became increasingly evident. Initial studies conducted with conventional magnetic resonance imaging (MRI) and Occipital Proton MR Spectroscopy. The techniques that the first functional and structural findings have been obtained are functional MRI (fMRI) and Diffusion-Tensor MRI (DTI), respectively. fMRI detects increased neuronal activity via changes in blood oxygenation, DTI is based on the movement principle of fluids in a plane connected to the nerve. In consecutive studies from 2006 to 2014, we aimed to evaluate the structural and functional extent of glaucomatous neurodegeneration in an attempt to develop techniques feasible for routine clinical application. In previous studies, we observed statistically significant correlation of glaucomatous neuro-degeneration between eye and visual pathways with our original techniques developed with 1,5T MRI. ON, CGL damage and cortical hypofunction were shown with DTI and fMRI, respectively. Our last cross-sectional DTI study, which is yet to be published, included 130 eyes with glaucoma. Statistically significant correlations were found between ganglion cell complex and apparent diffusion coefficient, λ1, λâ”´ of optic nerves. Strategies independent from IOP, concerning the area beyond the optic nerve head, are needed in the evaluation and treatment of glaucoma. As our studies showed, clinical instruments that are largely in use are also adequate for clinical trials to reveal the glaucoma-brain connection; however, more sophisticated techniques are being developed to illuminate that relation further. A more comprehensive understanding of retro bulbar glaucomatous damage will enable us to determine more efficient diagnosis, follow-up and treatment strategies and facilitate to answer important questions which remain unknown about this disease.