MRI Can Help Determine Glaucoma Severity
Study finds correlations between MRI maps of optic nerve, optic radiations and disease severity
THURSDAY, July 30 (HealthDay News) -- Magnetic resonance imaging of the optic nerve and optic radiations of the brain may offer a new diagnostic tool to evaluate severity of glaucoma, according to a study in the August issue of Radiology.
Francesco G. Garaci, M.D., of the University Hospital Tor Vergata in Rome, and colleagues examined 16 patients with primary open-angle glaucoma and established stages of severity (zero to five) using the Hodapp-Anderson-Parrish system. The patients, and a control group of 10 subjects without glaucoma, then underwent high-field-strength diffusion-tensor (DT) magnetic resonance (MR) imaging. Mean diffusivity and fractional anisotropy maps were created with the goal of determining whether DT MR imaging-derived factors could be used to determine disease severity.
The researchers found that DT MR imaging-derived mean diffusivity values for the optic nerve varied consistently with the glaucoma stage, while the mean fractional anisotropy values from DT MR imaging were inversely correlated with glaucoma stage. In comparisons with the control group, the optic radiations and optic nerves of glaucoma patients had significantly higher mean diffusivity and significantly lower fractional anisotropy.
"Glaucoma is a complex neurologic disease that affects optic nerves and optic radiations. The finding that DT MR imaging-derived mean diffusivity and fractional anisotropy in the optic nerves correlate with glaucoma severity suggests that these parameters could serve as complementary indicators of disease severity," the authors conclude.