DTI parameters of axonal integrity and demyelination of the optic radiation correlate with glaucoma indices

• Published in: Graefe's archive for clinical and experimental ophthalmology Vol. 251; no. 1; pp. 243 - 253
• Main Authors: Michelson, Georg, Engelhorn, Tobias, Wärntges, Simone, El Rafei, Ahmed, Hornegger, Joachim, Doerfler, Arnd
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.01.2013; Springer Nature B.V
• Subjects: Anisotropy; Axons - pathology; Case-Control Studies; Cerebral Small Vessel Diseases; Demyelinating Diseases - diagnosis; Diffusion Tensor Imaging; Female; Glaucoma; Glaucoma, Open-Angle - diagnosis; Humans; Low Tension Glaucoma - diagnosis; Male; Medicine; Medicine & Public Health; Middle Aged; Neurophthalmology; Ophthalmology; Optic Disk - pathology; Optic Nerve Diseases - diagnosis; Retinal Ganglion Cells - pathology; Retinal Neurons - pathology; Surveys and Questionnaires; Visual Field Tests; Visual Fields; Glaucoma; Optic nerve head; Optic radiation; Diffusion tensor imaging
• ISSN: 0721-832X; 1435-702X; 1435-702X
• DOI: 10.1007/s00417-011-1887-2

Background In glaucoma, damage of retinal ganglion cells may continue to the linked optic radiations. This study investigates the correlation of glaucoma severity indicators with parameters of axonal and myelin integrity of the optic radiations. Methods In this observational case–control study, 13 patients with normal-tension glaucoma, 13 patients with primary open-angle glaucoma, and seven control subjects (mean age, 57.6 ± 12.5 years) were randomly selected for diffusion tensor imaging (DTI) of the optic radiations. The results of the frequency doubling test (FDT) and the HRT-based linear discriminant functions of Burk (BLDF) and Mikelberg (MLDF) were correlated with the mean of the fractional anisotropy (FA), apparent diffusion coefficient (ADC), and radial diffusivity (RD) of the optic radiations. Multiple correlation analysis, corrected for age, stage of cerebral microangiopathy, diagnosis group, and gender was conducted at increasing thresholds of linear anisotropy (C L ) to reduce mismeasurements because of complex fiber situations. Results The best correlations were found for BLDF with FA at C L threshold 0.3 (0.594, p  = 0.001), with ADC at C L 0.4 (−0.511, p  = 0.005), and with RD at C L 0.4 (−0.585, p  = 0.001). MLDF correlated with FA at C L 0.4 (0.393, p  = 0.035). The FDT score correlated with FA at C L 0 (−0.491, p  = 0.007) and with RD at C L 0 (−0.375, p  = 0.045). Conclusions In glaucoma, DTI-derived parameters of the axonal integrity (FA, ADC) and demyelination (RD) of the optic radiation are linked to HRT-based indices of glaucoma severity and to impairment of the spatial-temporal contrast sensitivity.