Evaluation of corpus geniculatum laterale and vitreous fluid by magnetic resonance spectroscopy in patients with glaucoma; a preliminary study

Abstract

Purpose To determine whether metabolite changes at cellular level occur in vitreous and lateral geniculate body (LGB) in patients with glaucoma by magnetic resonance spectroscopy (MRS). Methods A total of 29 eyes of 29 patients with glaucoma, no existing ocular pathology and systemic disease (group 1), and 13 eyes of 13 healthy individuals whose routine ophthalmological examinations were normal (group 2) were included in the study. Singlevoxel MRS examination was performed by placing region of interest in vitreous and LGB. Glutamate-glutamine (Glx)/creatin (Cr) ratios and lactate peaks in the vitreous, and the Glx/Cr, N-acetyl aspartate (NAA)/Cr, choline (Cho)/Cr ratios in the ipsilateral area of LGB were evaluated. Results A statistically significant difference was found between the two groups for the Glx/Cr ratio in both the vitreous and LGB (P ¼ 0.0001). There was no statistically significant difference between the two groups for the NAA/Cr, and Cho/Cr ratios in the LGB (P ¼ 0.108). A lactate peak was established in the vitreous of 11 glaucoma patients. Conclusion Determining increased Glx/Cr ratios in both the vitreous and LGB of glaucoma patients, supports the theory of apoptosis in the etiopathogenesis of glaucoma. The MRS method, which can measure biochemical structures and metabolites of tissues, and also shows on a single spectrum, may be a new and noninvasive method for confirming the diagnosis of glaucoma and the role of apoptosis in the etiopathogenesis of glaucoma.

In vivo proton magnetic resonance spectroscopy (1H-MRS) evaluation of the metabolite concentration of optic radiation in primary open angle glaucoma

“…Another study by Doganay et al [17] differs from our study with respect to the site of measurement. There were indeed differences in both technique and patient selection.…”

“…By contrast, Doganay et al studied single-voxel 1H-MRS on the LGB and corpus vitreous of 29 glaucoma patients and 13 healthy subjects [17]. They found statistically significant reduction of Glx/Cr ratio in both vitreous body and LGB, but no metabolite alteration in NAA/Cr and Cho/Cr ratios in the LGB.…”

Using magnetic resonance imaging to assess visual deficits: a review

“…MRS was performed using a VOI in these two regions in a group of glaucoma patients. Analysis revealed significantly greater levels of Glx:Cr in both VOIs for the glaucoma patients compared to sighted controls, supporting the apoptosis theory in the aetiopathogenesis of glaucoma . MRS could therefore move the diagnosis of glaucoma forward enhancing the understanding and diagnosing of glaucoma at the cellular level.…”

Clinical Metabolomics and Glaucoma

“…In view of the apoptosis theory, in which the neurotoxicity of glutamate plays a pivotal role, a study was conducted with in vivo single-voxel NMR spectroscopy of the vitreous and lateral geniculate body of glaucoma patients. The authors found a higher glutamine-glutamate/Cr ratio in the vitreous and in the lateral geniculate body compared to healthy controls [10] . All of the study subjects were Caucasian, and hypertension, diabetes, and degenerative central nervous system diseases were excluded.…”

“…In ophthalmology, metabolomics has been used to study various eye diseases including glaucoma [10][11][12][13][14][15][16] , age-related macular degeneration [17][18][19] , diabetic retinopathy [20][21][22] , keratoconus [23] , refractive error [24,25] , retinal detachment [26] , uveitis [27,28] , dry eye [29,30] , and other ocular surface diseases [31] . Analyses have been performed on tear fluid [23,[29][30][31][32] , aqueous humor [24,25,33,34] , vitreous humor [20,26,27,35,36] , cornea [37][38][39] , conjunctiva [40] , and lens [41,42] samples.…”