scholarly journals Pupillary Response to Chromatic Light Stimuli as a Biomarker at the Early Stage of Glaucoma

2021 ◽  
Author(s):  
Carla Arévalo López ◽  
Samuel Madariaga Román ◽  
Ivan Plaza
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Early Stage ◽  
Open Angle Glaucoma ◽  
Visual Image ◽  
Pupillary Response ◽  
Retinal Ganglion ◽  
Irreversible Damage ◽  
Pupillary Reflex ◽  
Potential Biomarker

Abstract Glaucoma is a multifactorial neurodegenerative disease of the optic nerve currently considered a severe health problem because of its high prevalence, being the primary cause of irreversible blindness worldwide. The most common type corresponds to Primary Open-Angle Glaucoma (POAG). Glaucoma produces, among other alterations, a progressive loss of Retinal Ganglion Cells (RGC) and its axons, key to generate the action potential that reaches the visual cortex to create the visual image. It indicates a Visual Field (VF) loss whose main feature is to be painless, and this makes early detection difficult, causing a late diagnosis and delaying a timely treatment indication that slows down its progression. Intrinsically photosensitive Retinal Ganglion Cells (ipRGCs), which represent a subgroup of RGCs being sensitive to damage, are characterized by reacting to short-wave light stimulation close to 480 nm and among their non-visual function, the role in the generation of the pupillary reflex stands out. Currently, the sensitivity of clinical trials correlates to RGC damage, however the need for an early damage biomarker is still relevant. It is an urgent task to create new diagnostic approaches to detect an early stage of glaucoma in a prompt, quick, and economical manner. We suggest evaluating the pupillary response to chromatic light as a potential biomarker of disease, its diagnostic benefit, and its cost-effectiveness in clinical practice to reduce irreversible damage caused by glaucoma.

Next-Generation Techniques for Analysis of Lamina Cribrosa Microstructure

2012 ◽  
Author(s):  
C. Ross Ethier ◽  
Richie Abel ◽  
E. A. Sander ◽  
John G. Flanagan ◽  
Michael Girard
Keyword(s):  
Risk Factor ◽  
Intraocular Pressure ◽  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Ganglion Cells ◽  
Lamina Cribrosa ◽  
Retinal Ganglion ◽  
Irreversible Damage ◽  
Ocular Disorders ◽  
The Brain

Glaucoma describes a group of potentially blinding ocular disorders, afflicting c. 60 million people worldwide. Of these, c. 8 million are bilaterally blind, estimated to increase to 11 million by 2020. The central event in glaucoma is slow and irreversible damage of retinal ganglion cells, responsible for carrying visual information from the retina to the brain (Figure 1). Intraocular pressure (IOP) is a risk factor for glaucoma1–4, and significant, sustained IOP reduction is unequivocally beneficial in the clinical management of glaucoma patients2, 3, 5. Unfortunately, we do not understand how elevated IOP leads to the loss of retinal ganglion cells.

scholarly journals Stem cell transplantation rescued a primary open-angle glaucoma mouse model

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Siqi Xiong ◽  
Ajay Kumar ◽  
Shenghe Tian ◽  
Eman E Taher ◽  
Enzhi Yang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mouse Model ◽  
Retinal Ganglion Cells ◽  
Primary Open Angle Glaucoma ◽  
Therapeutic Potential ◽  
Ganglion Cells ◽  
Open Angle Glaucoma ◽  
Retinal Ganglion ◽  
Upregulated Genes

Glaucoma is a leading cause of irreversible blindness. In this study, we investigated if transplanted stem cells are able to rescue a glaucoma mouse model with transgenic myocilin Y437H mutation and explored the possible mechanisms. Human trabecular meshwork stem cells (TMSCs) were intracamerally transplanted which reduced mouse intraocular pressure, increased outflow facility, protected the retinal ganglion cells and preserved their function. TMSC transplantation also significantly increased the TM cellularity, promoted myocilin secretion from TM cells into the aqueous humor to reduce endoplasmic reticulum stress, repaired the TM tissue with extracellular matrix modulation and ultrastructural restoration. Co-culturing TMSCs with myocilin mutant TM cells in vitro promoted TMSCs differentiating into phagocytic functional TM cells. RNA sequencing revealed that TMSCs had upregulated genes related to TM regeneration and neuroprotection. Our results uncovered therapeutic potential of TMSCs for curing glaucoma and elucidated possible mechanisms by which TMSCs achieve the treatment effect.

scholarly journals Cell-Subtype-Specific Remodeling of Intrinsically Photosensitive Retinal Ganglion Cells in Streptozotocin-Induced Diabetic Mice

2021 ◽  
Author(s):  
Wei-Yi Chen ◽  
Xu Han ◽  
Ling-Jie Cui ◽  
Chen-Xi Yu ◽  
Wen-Long Sheng ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Retinal Ganglion Cells ◽  
Visual Function ◽  
Functional Activity ◽  
Ganglion Cells ◽  
Early Stage ◽  
Retinal Ganglion ◽  
Diabetic Mice ◽  
Pupillary Light ◽  
Dendritic Branching

Recent evidence suggests that melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), a neuronal class regulating non-image forming (NIF) vision and generally thought to be injury-resistant, are dysfunctional in certain neurodegenerative diseases. Although disrupted NIF visual functions have been reported in patients and animals with diabetes, it remains controversial whether ipRGCs exhibit remodeling during diabetes and if so, whether such remodeling is variable among ipRGC subtypes. Here we demonstrate that survival, soma-dendritic profiles and melanopsin-based functional activity of M1 ipRGCs were unaltered in streptozotocin-induced 3-month diabetic mice. Such resistance remained at 6 months after streptozotocin administration. In contrast, M2/M3 ipRGCs underwent significant remodeling in diabetic mice, manifested by enlarged somata and increased dendritic branching complexity. Consistent with the unaltered melanopsin levels, the sensitivity of melanopsin-based activity was unchanged in surviving M2 cells, but their response gain displayed a compensatory enhancement. Meanwhile, the pupillary light reflex, a NIF visual function controlled by M2 cells, was found to be impaired in diabetic animals. The resistance of M1 cells might be attributed to the adjacency of their dendrites to capillaries, which makes them less disturbed by the impaired retinal blood supply at the early stage of diabetes.

scholarly journals Relationship between Daytime Sleepiness and Intrinsically Photosensitive Retinal Ganglion Cells in Glaucomatous Disease

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Carolina P. B. Gracitelli ◽  
Gloria Liliana Duque-Chica ◽  
Ana Laura de Araújo Moura ◽  
Marina Roizenblatt ◽  
Balazs V. Nagy ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Retinal Ganglion Cells ◽  
Daytime Sleepiness ◽  
Epworth Sleepiness Scale ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Pupillary Reflex

Patients with glaucoma showed to have higher daytime sleepiness measured by Epworth sleepiness scale. In addition, this symptom was associated with pupillary reflex and polysomnography parameters. These ipRGC functions might be impaired in patients with glaucoma, leading to worse quality of life.

Retinal Ganglion Cells Functional Changes in a Mouse Model of Alzheimer’s Disease Are Linked with Neurotransmitter Alterations

2021 ◽  
pp. 1-14
Author(s):  
Joaquín Araya ◽  
Felipe Bello ◽  
Gaganashree Shivashankar ◽  
David Neira ◽  
Claudia Durán-Aniotz ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Firing Rate ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Early Stage ◽  
Retinal Ganglion ◽  
Gamma Aminobutyric Acid ◽  
Functional Changes ◽  
Model Of Alzheimer’S Disease

Background: Alzheimer’s disease (AD) is the most prevalent form of dementia worldwide. This neurodegenerative syndrome affects cognition, memory, behavior, and the visual system, particularly the retina. Objective: This work aims to determine whether the 5xFAD mouse, a transgenic model of AD, displays changes in the function of retinal ganglion cells (RGCs) and if those alterations are correlated with changes in the expression of glutamate and gamma-aminobutyric acid (GABA) neurotransmitters. Methods: In young (2–3-month-old) and adult (6-7-month-old) 5xFAD and WT mice, we have studied the physiological response, firing rate, and burst of RGCs to various types of visual stimuli using a multielectrode array system. Results: The firing rate and burst response in 5xFAD RGCs showed hyperactivity at the early stage of AD in young mice, whereas hypoactivity was seen at the later stage of AD in adults. The physiological alterations observed in 5xFAD correlate well with an increase in the expression of glutamate in the ganglion cell layer in young and adults. GABA staining increased in the inner nuclear and plexiform layer, which was more pronounced in the adult than the young 5xFAD retina, altering the excitation/inhibition balance, which could explain the observed early hyperactivity and later hypoactivity in RGC physiology. Conclusion: These findings indicate functional changes may be caused by neurochemical alterations of the retina starting at an early stage of the AD disease.

scholarly journals Upregulation of IGF-I in the goldfish retinal ganglion cells during the early stage of optic nerve regeneration

2007 ◽  
Vol 50 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Yoshiki Koriyama ◽  
Keiko Homma ◽  
Kayo Sugitani ◽  
Yoshihiro Higuchi ◽  
Toru Matsukawa ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Nerve Regeneration ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Early Stage ◽  
Retinal Ganglion ◽  
Optic Nerve Regeneration ◽  
Igf I

scholarly journals Stem Cell Transplantation Rescued A Primary Open-Angle Glaucoma Mouse Model

2020 ◽  
Author(s):  
Siqi Xiong ◽  
Ajay Kumar ◽  
Shenghe Tian ◽  
Eman E. Taher ◽  
Enzhi Yang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mouse Model ◽  
Retinal Ganglion Cells ◽  
Primary Open Angle Glaucoma ◽  
Therapeutic Potential ◽  
Ganglion Cells ◽  
Open Angle Glaucoma ◽  
Retinal Ganglion ◽  
Upregulated Genes

AbstractGlaucoma is a leading cause of irreversible blindness. In this study, we investigated if exogenous stem cells are able to rescue a glaucoma mouse model with transgenic myocilin Y437H mutation and explored the possible mechanisms. Human trabecular meshwork stem cells (TMSCs) were intracamerally transplanted which reduced mouse intraocular pressure, increased outflow facility, protected the retinal ganglion cells and preserved their function. TMSC transplantation also significantly increased the TM cellularity, promoted myocilin secretion from TM cells into the aqueous humor to reduce endoplasmic reticulum stress, repaired the TM tissue with extracellular matrix modulation and ultrastructural restoration. Co-culturing TMSCs with myocilin mutant TM cells in vitro promoted TMSCs differentiating into phagocytic functional TM cells. RNA sequencing revealed that TMSCs had upregulated genes related to TM regeneration and neuroprotection. Our results uncovered therapeutic potential of TMSCs for curing glaucoma and elucidated possible mechanisms by which TMSCs achieve the treatment effect.

scholarly journals Genomic Locus Modulating Corneal Thickness in the Mouse Identifies POU6F2 as a Potential Risk of Developing Glaucoma

2017 ◽  
Author(s):  
Rebecca King ◽  
Felix L. Struebing ◽  
Ying Li ◽  
Jiaxing Wang ◽  
Allison Ashley Koch ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Retinal Ganglion Cells ◽  
Central Corneal Thickness ◽  
Primary Open Angle Glaucoma ◽  
Ganglion Cells ◽  
Open Angle Glaucoma ◽  
Corneal Thickness ◽  
Retinal Ganglion ◽  
Open Angle

AbstractPurpose: Central corneal thickness (CCT) is one of the most heritable ocular traits and it is also a phenotypic risk factor for primary open angle glaucoma (POAG). The present study uses the BXD Recombinant Inbred (RI) strains to identify novel quantitative trait loci (QTLs) modulating CCT in the mouse with the potential of identifying a molecular link between CCT and risk of developing POAG.Methods: The BXD RI strain set was used to define mammalian genomic loci modulating CCT, with a total of 818 corneas measured from 61 BXD RI strains (between 60-100 days of age). The mice were anesthetized and the eyes were positioned in front of the lens of the Phoenix Micron IV Image-Guided OCT system or the Bioptigen OCT system. CCT data for each strain was averaged and used to identify quantitative trait loci (QTLs) modulating this phenotype using the bioinformatics tools on GeneNetwork (www.genenetwork.org). The candidate genes and genomic loci identified in the mouse were then directly compared with the summary data from a human primary open-angle glaucoma (POGA) genome wide association study (NEIGHBORHOOD) to determine if any genomic elements modulating mouse CCT are also risk factors for POAG.Results: This analysis revealed one significant QTL on Chr 13 and a suggestive QTL on Chr 7. The significant locus on Chr 13 (13 to 19 Mb) was examined further to define candidate genes modulating this eye phenotype. For the Chr 13 QTL in the mouse, only one gene in the region (Pou6f2) contained nonsynonymous SNPs. Of these five nonsynonymous SNPs in Pou6f2, two resulted in changes in the amino acid proline which could result in altered secondary structure affecting protein function. The 7 Mb region under the mouse Chr 13 peak distributes over 2 chromosomes in the human: Chr 1 and Chr 7. These genomic loci were examined in the NEIGHBORHOOD database to determine if they are potential risk factors for human glaucoma identified using meta-data from human GWAS. The top 50 hits all resided within one gene (POU6F2), with the highest significance level of p = 10−6 for SNP rs76319873. POU6F2 is found in retinal ganglion cells and in corneal limbal stem cells. To test the effect of POU6F2 on CCT we examined the corneas of a Pou6f2-null mice and the corneas were thinner than those of wild-type littermates. In addition, these POU6F2 RGCs die early in the DBA/2J model of glaucoma than most RGCs.Conclusions: Using a mouse genetic reference panel, we identified a transcription factor, Pou6f2, that modulates CCT in the mouse. POU6F2 is also found in a subset of retinal ganglion cells and these RGCs are sensitive to injury.Authors SummaryGlaucoma is a complex group of diseases with several known causal mutations and many known risk factors. One well-known risk factor for developing primary open angle glaucoma is the thickness of the central cornea. The present study leverages a unique blend of systems biology methods using BXD recombinant inbred mice and genome-wide association studies from humans to define a putative molecular link between a phenotypic risk factor (central corneal thickness) and glaucoma. We identified a transcription factor, POU6F2, that is found in the developing retinal ganglion cells and cornea. POU6F2 is also present in a subpopulation of retinal ganglion cells and in stem cells of the cornea. Functional studies reveal that POU6F2 is associated the central corneal thickness and with susceptibility of retinal ganglion cells to injury.

Glaucoma management in the era of artificial intelligence

2019 ◽  
Vol 104 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Sripad Krishna Devalla ◽  
Zhang Liang ◽  
Tan Hung Pham ◽  
Craig Boote ◽  
Nicholas G Strouthidis ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Deep Learning ◽  
Retinal Ganglion Cells ◽  
Vision Loss ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Irreversible Damage ◽  
Diagnosis And Prognosis ◽  
Disease Prognosis

Glaucoma is a result of irreversible damage to the retinal ganglion cells. While an early intervention could minimise the risk of vision loss in glaucoma, its asymptomatic nature makes it difficult to diagnose until a late stage. The diagnosis of glaucoma is a complicated and expensive effort that is heavily dependent on the experience and expertise of a clinician. The application of artificial intelligence (AI) algorithms in ophthalmology has improved our understanding of many retinal, macular, choroidal and corneal pathologies. With the advent of deep learning, a number of tools for the classification, segmentation and enhancement of ocular images have been developed. Over the years, several AI techniques have been proposed to help detect glaucoma by analysis of functional and/or structural evaluations of the eye. Moreover, the use of AI has also been explored to improve the reliability of ascribing disease prognosis. This review summarises the role of AI in the diagnosis and prognosis of glaucoma, discusses the advantages and challenges of using AI systems in clinics and predicts likely areas of future progress.

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