scholarly journals Reduced Functional and Anatomic Interhemispheric Homotopic Connectivity in Primary Open-Angle Glaucoma: A Combined Resting State-fMRI and DTI Study

2018 ◽  
Vol 59 (5) ◽  
pp. 1861 ◽  
Author(s):  
Qian Wang ◽  
Weiwei Chen ◽  
Huaizhou Wang ◽  
Xun Zhang ◽  
Xiaoxia Qu ◽  
...  
2021 ◽  
Author(s):  
Giorgia Demaria ◽  
Azzurra Invernizzi ◽  
Daniel Ombelet ◽  
Joana Carvalho ◽  
Remco Renken ◽  
...  

Recent brain imaging studies have shown that the degenerative eye damage generally observed in the clinical setting, also extends intracranially. Both structural and functional brain changes have been observed in glaucoma participants, but we still lack an understanding of whether these changes also affect the integrity of cortical functional networks. This is relevant, as functional network integrity may affect the applicability of future treatments, as well as the options for rehabilitation or training. Here, we compare global and local functional connectivity between glaucoma and controls. Moreover, we study the relationship between functional connectivity and visual field (VF) loss. For our study, 20 subjects with primary open angle glaucoma (POAG) and 24 age similar healthy participants were recruited to undergo a complete ophthalmic assessment followed by two resting state (RS) (f)MRI scans. For each scan and for each group, the ROIs with EC values higher than the 95th percentile were considered the most central brain regions (hubs). Hubs for which we found a significant difference in EC in both scans between glaucoma and healthy were considered to provide evidence for network changes. In addition, for each participant, behavioural scores were derived based on the notion that a brain regions hub function might relate to the: 1) sensitivity of the worse eye, indicating disease severity, 2) sensitivity of both eyes combined, with one eye potentially compensating for loss in the other, or 3) difference in eye sensitivity, requiring additional network interactions. By correlating each of these VF scores and the EC values, we assessed whether VF defects could be associated with centrality alterations in POAG. Our results show that no functional connectivity disruptions were found at the global brain level in POAG participants. This indicates that in glaucoma global brain network communication is preserved. Furthermore, a positive correlation was found between the EC value of the Lingual Gyrus, identified as a brain hub, and the behavioral score for the VF sensitivity of both eyes combined. The fact that reduced local network functioning is associated with reduced binocular VF sensitivity suggests the presence of local brain reorganization that has a bearing on functional visual abilities.


2022 ◽  
Vol 13 ◽  
Author(s):  
Giorgia Demaria ◽  
Azzurra Invernizzi ◽  
Daniel Ombelet ◽  
Joana C. Carvalho ◽  
Remco J. Renken ◽  
...  

In glaucoma participants, both structural and functional brain changes have been observed, but we still have insufficient understanding of how these changes also affect the integrity of cortical functional networks, and how these changes relate to visual function. This is relevant, as functional network integrity may affect the applicability of future treatments, as well as the options for rehabilitation or training. Here, we compare global and local functional connectivity in local and global brain networks between glaucoma and control participants. Moreover, we study the relationship between functional connectivity and visual field (VF) loss. For our study, 20 subjects with primary open-angle glaucoma (POAG) and 24 age-similar healthy participants were recruited to undergo an ophthalmic assessment followed by two resting-state (RS) (f)MRI scans. For each scan and for each group, the ROIs with eigenvector centrality (EC) values higher than the 95th percentile were considered the most central brain regions (“hubs”). Hubs for which we found a significant difference in EC in both scans between glaucoma and healthy participants were considered to provide evidence for network changes. In addition, we tested the notion that a brain region's hub function in POAG might relate to the severity of a participant's VF defect, irrespective of which eye contributed mostly to this. To determine this, for each participant, eye-independent scores were derived for: (1) sensitivity of the worse eye – indicating disease severity, (2) sensitivity of both eyes combined – with one eye potentially compensating for loss in the other, or (3) difference in eye sensitivity – potentially requiring additional network interactions. By correlating each of these VF scores and the EC values, we assessed whether VF defects could be associated with centrality alterations in POAG. Our results show that no functional connectivity disruptions were found at the global brain level in POAG participants. This indicates that in glaucoma global brain network communication is preserved. Furthermore, for the Lingual Gyrus, identified as a brain hub, we found a positive correlation between the EC value and the VF sensitivity of both eyes combined. The fact that reduced local network functioning is associated with reduced binocular VF sensitivity suggests the presence of local brain reorganization that has a bearing on functional visual abilities.


Author(s):  
E. N. Simakova ◽  
O. V. Stenkova

Introduction. Glaucoma is one of the most significant eye diseases. It is often diagnosed, not always amenable to therapy, and can lead to a complete loss of visual functions. In recent years, the method of osteopathic correction has become widespread as one of the effective methods of treatment and rehabilitation of patients with pathologies of various body systems. In the pathogenesis of glaucoma, it is customary to distinguish a dystrophic concept, which considers primary open-angle glaucoma as a result of dystrophic changes in the connective tissue, as well as in the endothelial lining of the trabeculae and Schlemm′s canal, especially destructive changes in mitochondria and the alteration of their functional activity. A vascular concept is also distinguished. According to this concept, the central link in the pathogenesis of glaucoma is circulatory disorder in the ciliary vessels, ocular artery, and major vessels of the head and neck, it can be assumed that osteopathic correction in the treatment of patients with open-angle glaucoma will be pathogenetically substantiated and will have a positive effect on intraocular pressure and trophicity of the optic nerve. The goal of research — to study the influence of in osteopathic correction on the nature of unoperated glaucoma (stage IIA) and to substantiate the possibility of using osteopathic correction in the complex treatment of patients with this pathology.Materials and methods. A prospective controlled randomized study was conducted at 52 city polyclinics, branch 3, Moscow, from January 2018 to January 2019. 40 patients (70 eyes) aged 50 to 75 years with primary open-angle glaucoma IIA stage were examined. At this stage of the disease, patients most often seek medical care and the issue of conservative management is primarily considered. All patients were divided into two groups of 20 people: the main group and the control group. The treatment in the main group included hypotensive drug therapy and osteopathic correction. Patients of the control group received only drug therapy. All patients underwent ophthalmic (visometry, tonometry, perimetry) and osteopathic examination twice: before the treatment and after 3 months.Results. For patients with primary open-angle IIA non-operated glaucoma, regional (most often regions of the head, neck, dura mater) and local (abdominal diaphragm, iliac bones, hip and knee joints) somatic dysfunctions were the most typical. In the main group a statistically significant decrease in the frequency and severity of dysfunctions at all levels was stated. Also, in patients receiving osteopathic correction, a significant decrease in the level of intraocular pressure and perimetric indices was noted. In patients of the control group, no reliable changes in these indicators were obtained.Conclusion. The results obtained indicate that osteopathic correction is clinically effective in the complex treatment of patients with primary open-angle II A glaucoma.


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