Project description:Traumatic optic neuropathy (TON) is the loss of vision secondary to trauma. Approximately two weeks after traumatic damage, diffuse retinal ganglion cell loss and axon degeneration of the optic nerve are exhibited [1]. Here we present the changes that occur in the optic nerve lipidome of two-month-old C57BL/6J mice following sonication-induced TON (SI-TON), which closely models the indirect clinical mechanism in TON. Optic nerves were harvested at three time points following injury: 1-day, 7-days, and 14-days for comparison with the control group (uninjured optic nerves from 2-month-old mice). The optic nerves were subjected to mass spectrometry and bioinformatic analysis using LipidSearch 4.1.3 and Metaboanalyst 4.0. This data pertains to the lipidome at each time point following indirect trauma to the optic nerve. The data presented here will augment investigation into the neurodegenerative process. The data is available at Metabolomics Workbench [http://www.metabolomicsworkbench.org (Project ID: PR000859)].
Project description:The optic nerve is part of the mammalian adult central nervous system (CNS) and has limited capability to regenerate after injury. Deletion of phosphatase and tensin homolog (PTEN), a negative regulator of the PI3 kinase/Akt pathway, has been shown to promote regeneration in retinal ganglion cells (RGCs) after optic nerve injury [1]. We present the lipidome of adult PTENloxP/loxP mice subjected to intravitreal injection of adeno-associated viruses expressing Cre (AAV-Cre) as a model of CNS neuroregeneration. At 4 weeks old, PTENloxP/loxP mice were intravitreally-injected with 2-3 μl of either AAV-Cre (KO) or AAV-PLAP (control), and two weeks later optic nerve crush was performed. At indicated time-points after crush (0 days, 7 days, 14 days), mice were euthanized and optic nerves were immediately dissected out, and then flash frozen on dry ice. A modified Bligh and Dyer [2] method was used for lipid extraction from the optic nerves, followed by liquid chromatography-mass spectrometry (LC MS-MS) lipid profiling using a Q-Exactive Orbitrap instrument coupled with Accela 600 HPLC. The raw scans were analysed with LipidSearch 4.2 and the statistical analysis was conducted through Metaboanalyst 4.0. This data is available at Metabolomics Workbench, study ID ST001477.
Project description:BackgroundTraumatic optic neuropathy (TON) is an important cause of severe visual loss following blunt or penetrating head trauma. Following the initial injury, optic nerve swelling within the optic nerve canal can result in secondary retinal ganglion cell loss. Optic nerve decompression with steroids or surgical interventions or both has therefore been advocated as a means of improving visual prognosis in TON.ObjectivesThe aim of this review was to examine the effectiveness and safety of using steroids in TON.Search methodsWe searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to May 2013), EMBASE (January 1980 to May 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to May 2013), Web of Science Conference Proceedings Citation Index- Science (CPCI-S) (January 1990 to May 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (http://clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 21 May 2013. We also searched the reference lists of included studies, other reviews and book chapters on TON to find references to additional trials. The Science Citation Index was used to look for papers that cited the studies included in this review. We did not manually search any journals or conference proceedings. We contacted trial investigators and experts in the field to identify additional published and unpublished studies.Selection criteriaWe planned to include only randomised controlled trials (RCTs) of TON in which any steroid regime, either on its own or in combination with surgical optic nerve decompression, was compared to surgery alone or no treatment.Data collection and analysisTwo review authors independently assessed the titles and abstracts identified from the electronic searches.Main resultsWe included one study that met our selection criteria; a double-masked, placebo-controlled, randomised trial of high dose intravenous steroids in patients with indirect TON diagnosed within seven days of the initial injury. A total of 31 eligible participants were randomised to receive either high dose intravenous steroids (n = 16) or placebo (n = 15), and they were all followed-up for three months. Mean final best corrected visual acuity (BCVA) was 1.78±1.23 Logarithm of the Minimum Angle of Resolution (LogMAR) in the placebo group, and 1.11±1.14 LogMAR in the steroid group. The mean difference in BCVA between the placebo and steroid groups was 0.67 LogMAR (95% confidence interval -1.54 to 0.20), and this difference was not statistically significant (P = 0.13). At three months follow-up, an improvement in BCVA of 0.40 LogMAR occurred in eight eyes (8/15, 53.3%) in the placebo group, and in 11 eyes (11/16, 68.8%) in the treatment group. This difference was not statistically significant (P = 0.38).Authors' conclusionsThere is a relatively high rate of spontaneous visual recovery in TON and there is no convincing data that steroids provide any additional visual benefit over observation alone. Recent evidence also suggests a possible detrimental effect of steroids in TON and further studies are urgently needed to clarify this important issue. Each case therefore needs to be assessed on an individual basis and proper informed consent is paramount.
Project description:The aim of this article is to evaluate current literature on investigation and management of traumatic optic neuropathy (TON), propose recommendations for diagnosis and management, and explore novel future treatments. TON, though uncommon, causes substantial visual loss. Without clear guidelines, there is much ambiguity regarding its diagnosis and management. Investigation and treatment (conservative, medical, surgical, and combined) vary widely between centers. Electronic databases PubMed, MEDLINE, PROSPERO, CENTRAL, and EMBASE were searched for content that matched "Traumatic optic neuropathy." Articles with abstracts and full text available, published in the past 10 years, written English and limited to human adults, were selected. All study designs were acceptable except case reports and case series with fewer 10 patients. All abstracts were then evaluated for relevance. References of these studies were evaluated and if also relevant, included. A total of 2,686 articles were retrieved and 43 examined for relevance. Of these, 23 articles were included. TON is a clinical diagnosis. Visual-evoked potential is useful in diagnosis and prognosis. Computed tomography demonstrates canal fractures and concomitant injuries. Magnetic resonance images should be reserved for select and stable patients. Conservative treatment is appropriate in mild TON. Steroids are of questionable benefit and may be harmful. Surgery should be reserved for patients with radiological evidence of compression and individualized.
Project description:PurposeTo identify optic nerve (ON) lipid alterations associated with sonication-induced traumatic optic neuropathy (TON).DesignExperimental study.SubjectsA mouse model of indirect TON was generated using sound energy concentrated focally at the entrance of the optic canal using a laboratory sonifier with a microtip probe.MethodsAnalyses of datasets generated from high-performance liquid chromatography-electrospray tandem mass spectrometry of ONs dissected from the head of the ON to the optic chiasm at 1 day, 7 days, and 14 days postsonication compared with that in nonsonicated controls.Main outcome measuresLipid abundance alterations in postsonicated ONs were evaluated using 1-way analysis of variance (false discovery rate-adjusted significant P value < 0.01), lipid-related gene sets, biochemical properties, and receiver operating characteristic to identify lipids associated with optic neuropathy.ResultsThere were 28 lipid species with significantly different abundances across the control and postsonication groups. The 2 most significantly upregulated lipids included a sphingomyelin (SM) species, SM(d40:7), and a hexosylceramide (CerG1) species, CerG1(d18:1/24:2). Hexosylceramide (d18:1/24:2) was noted to have a stepwise increasing trend from day 1 to day 14 after sonication-induced optic neuropathy. Investigation of biophysical properties showed notable enrichment of lipids with high and above-average transition temperatures at day 14 after sonication. Lipid-related gene set analysis revealed enrichment in sphingolipid and glycosphingolipid metabolic processes. The best classifier to differentiate day 14 postsonication from controls, based on area under the receiver operating characteristic curve, was CerG1(d18:1/24:2) (area under the receiver operating characteristic curve: 1).ConclusionsTemporal alterations in sphingolipid metabolism and biochemical properties were observed in the ON of mice after sonication-induced optic neuropathy, with notable elevations in sphingomyelin and hexosylceramide species. Hexosylceramide (d18:1/24:2) may be associated with damage after indirect trauma, indicating that lipid membrane abnormalities may be a mediator of pathology due to trauma.
Project description:The right optic nerve of adult, 6 month to 1 year old, female and male Danio rerio were crushed and collected three days after. Matching controls of uninjured left optic nerves were also collected. The tissue was dissected from euthanized fish and frozen on dry ice. Samples were pooled for each category (female crush, female control, male crush, male control) n = 24 to obtain sufficient tissue for analysis. The brain from one male fish was also collected for control/calibration. Lipid extraction was done with the Bligh and Dyer [1] method, followed by untargeted liquid chromatography-mass spectrometry (LC MS-MS) lipid profiling using a Q-Exactive Orbitrap instrument coupled with Vanquish Horizon Binary UHPLC LC-MS system. The lipids were identified and quantified with LipidSearch 4.2.21 and the statistical analysis was conducted through Metaboanalyst 5.0. This data is available at Metabolomics Workbench, Study ID ST001725.
Project description:Traumatic brain injury (TBI) results in a number of impairments, often including visual symptoms. In some cases, visual impairments after head trauma are mediated by traumatic injury to the optic nerve, termed traumatic optic neuropathy (TON), which has few effective options for treatment. Using a murine closed-head weight-drop model of head trauma, we previously reported in adult mice that there is relatively selective injury to the optic tract and thalamic/brainstem projections of the visual system. In the current study, we performed blunt head trauma on adolescent C57BL/6 mice and investigated visual impairment in the primary visual system, now including the retina and using behavioral and histologic methods at new time points. After injury, mice displayed evidence of decreased optomotor responses illustrated by decreased optokinetic nystagmus. There did not appear to be a significant change in circadian locomotor behavior patterns, although there was an overall decrease in locomotor behavior in mice with head injury. There was evidence of axonal degeneration of optic nerve fibers with associated retinal ganglion cell death. There was also evidence of astrogliosis and microgliosis in major central targets of optic nerve projections. Further, there was elevated expression of endoplasmic reticulum (ER) stress markers in retinas of injured mice. Visual impairment, histologic markers of gliosis and neurodegeneration, and elevated ER stress marker expression persisted for at least 30 days after injury. The current results extend our previous findings in adult mice into adolescent mice, provide direct evidence of retinal ganglion cell injury after head trauma and suggest that axonal degeneration is associated with elevated ER stress in this model of TON.
Project description:Traumatic optic neuropathy (TON) is a degenerative process that occurs in a subset of patients following blunt force trauma to the head. This condition is characterized by retinal ganglion cell (RGC) death and axon degeneration within the optic nerve [1]. At the cellular level, mitochondrial changes are associated with many optic neuropathies [2, 3]. Here, we provide a dataset demonstrating changes in the optic nerve mitochondrial lipid profile of a sonication-induced traumatic optic neuropathy (SI-TON) mouse model at 1, 7, and 14 days after injury. 32 C57BL/6J mice were separated into 4 groups (control, 1, 7, and 14 days) of 8, with 4 males and 4 females in each. Mice were exposed to sonication-induced trauma as described previously (by Tao et al) and optic nerves were harvested at 1, 7, or 14 days following injury [4]. Mitochondria were isolated from homogenized optic nerves and lipids were extracted. Extracted mitochondrial lipids were analysed with a Q-Exactive Orbitrap Liquid Chromatography-Mass Spectrometer (LC MS-MS). Further analysis of raw data was conducted with LipidSearch 4.1.3 and Metaboanalyst 4.0. This data is publicly available at the Metabolomics Workbench, http://www.metabolomicsworkbench.org (Project ID: PR000905).
Project description:IntroductionThe treatment of traumatic optic neuropathy (TON) is highly controversial with a lack of substantiated evidence to support the use of corticosteroids or surgical decompression of the optic nerve. The aim of the study was to determine if there was a general consensus in the management of TON despite controversy in the literature.MethodsAn anonymous survey of members of the American Society of Ophthalmic Plastic and Reconstructive Surgery and the North American Neuro-Ophthalmology Society regarding their practice patterns in the management of patients with TON was performed.ResultsThe majority of 165 respondents indicated that they treated TON with corticosteroids (60%) while a significant minority (23%) performed surgical interventions (P < 0.0001). Subgroup analysis comparing rates of treatment with steroids among oculoplastic surgeons and neuro-ophthalmologists (67% vs. 47%) was not significant (Fisher's Exact test [FET], P =0.11) while results did suggest that a higher proportion of oculoplastic surgeons (33%) than neuro-ophthalmologists (11%) recommended surgical intervention (FET, P =0.004). In cases where visual acuity exhibited a downward trend treatment with steroids was the most commonly employed management. In general, neuro-ophthalmologists trended toward observation over treatment in TON patients with stable visual acuity while oculoplastic surgeons favored treatment with corticosteroids.ConclusionsIn spite of the lack of class I evidence supporting intervention of TON, the majority of respondents were inclined to offer corticosteroid treatment to patients whose visual acuity showed progressive decline following injury.