Diffusion tensor imaging detects rarefaction of optic radiation in glaucoma patients

Rationale and objectives: Diffusion tensor imaging (DTI) can depict rarefaction of the optical fibres. Hence, we applied DTI to assess pathological changes of the optic radiation in glaucoma patients.

Materials and methods: Fifty glaucoma patients and 50 healthy age-matched controls were examined by a 3T high-field magnetic resonance scanner. Fiber tracts were volume rendered using a semiquantitative approach to assess rarefaction and results were correlated with the extent of optic nerve atrophy and reduced spatial-temporal contrast sensitivity of the retina using established ophthalmological examinations.

Results: Twenty-two glaucoma patients (44%) showed significant rarefaction of the optic radiation: the volume was reduced to 67 ± 16% compared with controls. Hereby, the glaucomatous optic nerve atrophy stage correlated with the presence of DTI-derived rarefied optic radiation (Kendall tau-b 0.272, P = .016). Aside, cerebral microangiopathy affecting the optic radiation was significantly higher among glaucoma patients compared to controls (10 patients compared with 2 patients, P < .05).

Conclusion: In patients with glaucomatous optic nerve atrophy, there is anterograde and-most likely because of microangiopathic lesions within the optic radiation-retrograde transneuronal rarefaction of the optic radiation that can be assessed in vivo using DTI with good correlation to established ophthalmological examinations.