Traumatic Brain Injury Induced Neuroprotection of Retinal Ganglion Cells to Optic Nerve Crush

Comparison of Surgical Decompression and Steroid Therapy for the Management of Traumatic Optic Neuropathy: A Systematic Review and Meta-Analysis

Study Design

A systematic review and meta-analysis.

Objective

Treatment of traumatic optic neuropathy (TON) has been a subject of debate for many decades due to the scarcity of evidence-based treatment protocols. This review compares surgical decompression (SD) and steroid therapy (ST) as treatment approaches in TON patients.

Methods

A PRISMA-guided systematic review using PubMed, Embase, Ovid and Scopus databases was performed till the last search date of July 31st 2021. The outcome of interest was an improvement in visual acuity. A meta-analysis of the odds ratio was performed using a random-effect model and sub-group analysis based upon criteria for assessment of improvement in visual acuity.

Results

Sixteen studies (including 1046 patients) were included in the review. The review could identify 590 patients treated with SD and 456 treated with ST. In addition, there was a second cohort of patients presenting with NLP (no light perception). A meta-analysis with a sub-group analysis revealed that there was statistically no significant difference between the two treatment approaches in terms of improvement in VA.

Conclusions

There is no difference in treatment results of SD or ST for TON. Several treatment protocols and different criteria for assessing visual acuity led to difficulty in generating evidence for selecting the correct treatment approach.

T Cell-Mediated Autoimmunity in Glaucoma Neurodegeneration

Glaucoma as the leading neurodegenerative disease leads to blindness in 3.6 million people aged 50 years and older worldwide. For many decades, glaucoma therapy has primarily focused on controlling intraocular pressure (IOP) and sound evidence supports its role in delaying the progress of retinal ganglial cell (RGC) damage and protecting patients from vision loss. Meanwhile, accumulating data point to the immune-mediated attack of the neural retina as the underlying pathological process behind glaucoma that may come independent of raised IOP. Recently, some scholars have suggested autoimmune aspects in glaucoma, with autoreactive T cells mediating the chief pathogenic process. This autoimmune process, as well as the pathological features of glaucoma, largely overlaps with other neurodegenerative diseases in the central nervous system (CNS), including Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. In addition, immune modulation therapy, which is regarded as a potential solution for glaucoma, has been boosted in trials in some CNS neurodegenerative diseases. Thus, novel insights into the T cell-mediated immunity and treatment in CNS neurodegenerative diseases may serve as valuable inspirations for ophthalmologists. This review focuses on the role of T cell-mediated immunity in the pathogenesis of glaucoma and discusses potential applications of relevant findings of CNS neurodegenerative diseases in future glaucoma research.

Retracted: Knockdown of long noncoding RNA GAS5 attenuates H2 O2 -induced damage in retinal ganglion cells through upregulating miR-124: Potential role in traumatic brain injury

BACKGROUND

Optic nerve injury is one of the most common and serious complications in traumatic brain injury (TBI). Alleviating degree of optic nerve injury is important to cure of TBI. This study explored the role of long noncoding RNA (lncRNA) GAS5 in mice retinal ganglion cells (RGCs) suffered to H₂ O ₂ injury.

METHODS

Primary RGC (PRGCs) were treated with H₂ O ₂ to simulate an in vitro oxidation stress model. LncRNA GAS5 and miR-124 expressions were knocked down by cell transfection with short-hairpin RNA against GAS5 and miR-124 inhibitor, and the transfection efficiency was determined by qRT-PCR. Cell viability, apoptotic cell rate, and production of reactive oxygen species (ROS) was analyzed by CCK-8 assay, PI/FITC-Annexin V method, and DCFH-DA fluorometric assay. Cell apoptosis-associated proteins as well as activations of JAK/STAT3 signaling and JNK signaling were analyzed by Western blot.

RESULTS

H₂ O ₂ treatment-induced cell injury was inhibited by lncRNA GAS5 silence. Specifically, knockdown of GAS5 improved viability of primary PRGCs, inhibited apoptosis, decreased ROS expression, increased antiapoptosis proteins' expressions, and decreased proapoptosis proteins' expressions. It was also found that miR-124 inhibitor treatment impaired the cell protective effect of GAS5 silence, indicating low level of GAS5 protected PRGCs via upregulating miR-124. GAS5 silence might exert cytoprotection effect via activating JAK/STAT3 signaling pathway and inhibiting activation of JNK signaling pathway.

CONCLUSION

Knocking down lncRNA GAS5 alleviated H₂ O ₂ -induced injury in PRGCs via upregulation of miR-124, which might dependent on activation of JAK/STAT3 signaling pathway and inhibition of JNK signaling pathway.

An insight into the vision impairment following traumatic brain injury

Traumatic brain injury (TBI) is one of the major cause of morbidity and mortality and it affects more than 1.7 million Americans each year. Depending on its location and severity, TBI leads to structural and functional damage in several parts of the brain such as cranial nerves, optic nerve tract or other circuitry involved in vision, and occipital lobe. As a result, the function associated with vision processing and perception are significantly affected and cause blurred vision, double vision, decreased peripheral vision and blindness. In this mini-review, we will focus the recent progress made to understand the pathology and underlying cellular/molecular mechanisms involved in the impairment of the integrity of visual systems following TBI.

Overview of Traumatic Brain Injury: An Immunological Context

Traumatic brain injury (TBI) afflicts people of all ages and genders, and the severity of injury ranges from concussion/mild TBI to severe TBI. Across all spectrums, TBI has wide-ranging, and variable symptomology and outcomes. Treatment options are lacking for the early neuropathology associated with TBIs and for the chronic neuropathological and neurobehavioral deficits. Inflammation and neuroinflammation appear to be major mediators of TBI outcomes. These systems are being intensively studies using animal models and human translational studies, in the hopes of understanding the mechanisms of TBI, and developing therapeutic strategies to improve the outcomes of the millions of people impacted by TBIs each year. This manuscript provides an overview of the epidemiology and outcomes of TBI, and presents data obtained from animal and human studies focusing on an inflammatory and immunological context. Such a context is timely, as recent studies blur the traditional understanding of an “immune-privileged” central nervous system. In presenting the evidence for specific, adaptive immune response after TBI, it is hoped that future studies will be interpreted using a broader perspective that includes the contributions of the peripheral immune system, to central nervous system disorders, notably TBI and post-traumatic syndromes.

Traumatic optic neuropathy: an evolving understanding

PURPOSE

To critically review the treatment of traumatic optic neuropathy.

DESIGN

A perspective of clinical and basic science studies related to traumatic optic neuropathy and its treatment.

METHODS

Published clinical and basic science studies on traumatic optic neuropathy were critically reviewed and interpreted.

RESULTS

Clinical progress in the treatment of traumatic optic neuropathy is limited by small clinical studies lacking appropriate control groups. The Corticosteroid Randomization for Acute Head Trauma (CRASH) trial found an increased rate of death among patients with acute head trauma treated with high-dose corticosteroids compared to placebo-treated patients (21% vs 18%, P = .0001). Recent animal studies also suggest that high-dose corticosteroids are toxic to the injured optic nerve.

CONCLUSIONS

The Corticosteroid Randomization for Acute Head Trauma study is immediately relevant to the treatment of traumatic optic neuropathy as individuals with traumatic optic neuropathy often have concomitant head trauma. High-dose corticosteroids for traumatic optic neuropathy will result in a measurable loss of life in patients who also have a brain injury. Death has never been an endpoint for traumatic optic neuropathy studies. Given human and animal data suggesting that treatment is harmful and the lack of demonstrated clinical efficacy, corticosteroids should not be used to treat traumatic optic neuropathy. The benefit of optic canal decompression is also unclear. There is a need to identify traumatic optic neuropathy soon after injury to further define the natural history of this injury. This information will provide a basis for assessing potential future treatments for traumatic optic neuropathy.