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திறந்த அணுகல்

சுருக்கம்

Changes in the Visual Cortex in Patients with High-Tension Glaucoma

Jan Lešták, Jaroslav Tintěra, Martin Kynčl, Zuzana Svatá, Jirí Obenberger and Andrea Saifrtová

Objective: To verify whether there is a correlation between visual field changes in high-tension glaucoma and changes in functional magnetic resonance of the visual cortex.
Methods and patients: The authors examined nine patients with high-tension glaucoma in different stages by functional magnetic resonance (fMRI). The measurements were carried out on the Philips Achieva 3T TX MR system using the BOLD method. Optical stimulation was provided by a black and white checkerboard alternated with its negative image with a frequency of 2 Hz. Each measurement consisted of a sequence of five 30-second active phase periods and five resting periods of the same length. The obtained data were processed using SPM8 software.
The complex ophthalmological examination was supplemented by the visual field in the rapid threshold program mode. The sum of sensitivities in the homolateral halves of the visual fields (ranging from 0-22 degrees) was compared to the extent of fMRI contralateral activity of the visual cortex.
The group was compared to a group of eight healthy persons.
Results: The obtained data were subjected to a statistical analysis (Non-parametric Spearman’s rank correlation coefficient) which showed a medium-grade correlation between the visual field changes and the changes in the visual cortex. R=0.667 (p<0.05), R=0.767 (p< 0.016) respectively.
Conclusion: The authors proved that the progression of glaucoma disease corresponds to the functional changes in the cerebral cortex. The loss of ganglion cells of the striate cortex most probably results in the interconnection of the optical radiation with the functional ganglion cells of the temporal lobe.