JUL 23, 2014
This retrospective study found that evaluation of the optic nerve using MRI may be a valuable objective method for assessing glaucomatous degeneration, including the function of the macula.
The study included 38 eyes of 19 patients with open-angle glaucoma who were scanned with T2-weighted and 3-T diffusion tensor MRI. Parameters of the optic nerve, including fractional anisotropy, apparent diffusion coefficient and cross-sectional area, were determined. Conventional parameters of glaucomatous damage, including circumpapillary and macular retinal nerve fiber layer thickness, and mean deviation and average total deviation of the central 16 test points from the Humphrey Field Analyzer, were then compared with the MRI-derived parameters.
Mean deviation was significantly correlated with all MRI parameters. Circumpapillary retinal nerve fiber layer thickness was significantly correlated with fractional anisotropy and cross-sectional area but not apparent diffusion coefficient. Central macular function and macular retinal nerve fiber layer thickness were also significantly correlated with MRI parameters.
The authors conclude that optic nerve atrophy provides a good representation of glaucomatous damage, and the cross-sectional area of the optic nerve has a strong potential for use in the objective examination of glaucoma patients. They note that disturbance in the central visual field affects quality of life for glaucoma patients, and these MRI parameters also correlated to macular damage in glaucoma.