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Abstract #26516 Published in IGR 12-3
Neuro-imaging examination of glaucomatous visual field defects
Yoshida M; Boucard CC; Hernowo AT; Ida M; Nishio T; Nishimoto F; Kato M; Nguyen Th; Istoc A; Iba-Zizen MTNeuro-Ophthalmology 2010; 34: 180-181
AIM: Glaucoma is associated with specific optic disk changes and corresponding visual field defects. Recently, Optical Coherence Tomography (OCT) makes it possible to measure the retinal nerve fibre layer thickness. OCT measurement are quantitatively comparable to the visual field testing for glaucoma in the modern standard clinical setting. On the other hand, a recent study showed structural changes in the lateral geniculate nucleus (LGN) andvisual cortex of a glaucoma patient (1,2). In our study we measured the intracranial structures along the visual pathway using MRI and compared them between a glaucoma and a control group. METHODS: Ten participants diagnosed as primary open angle glaucoma were recruited. The control group included ten age matched subjects without pathological history except for cataract surgery. All participants gave their informed consent prior to participation. Static visual field testing and OCT measurements were performed. Different structures of the visual pathway were examined with a 3T clinical MR scanner. Diffusion tensor imaging (DTI) was used to measure fractional anisotropy (FA) in the optic radiations. 3D T1 weighted anatomical images were used to compare grey and white matter volumes between the glaucoma and control group. RESULTS: Compared to the control group, our analysis showed statistically decreased FA values in the optic radiations of the glaucoma group. White and grey matter volumes were as well statistically lower in the region of the optic chiasm and optic tract and in the anterior part of primary visual cortex. Additional analysis showed positive linear correlations between the different structures and the clinical data. CONCLUSION: These results suggest that structural changes in the optic chiasm, optic tract, optic radiations and visual cortex occur in glaucoma. This non-invasive technique enables the exploration of changes in cerebral structures such as tracts and cortex related to glaucomatous damage.
M. Yoshida. Department of Ophthalmology, Jikei University, School of Medicine, TokyoJapan.
Classification:
2.16 Chiasma and retrochiasmal central nervous system (Part of: 2 Anatomical structures in glaucoma)
6.6.2 Automated (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
6.9.5 Other (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
