Toxic Optic Neuropathy Research Articles

Detection of Optic Disc Abnormalities in Color Fundus Photographs Using Deep Learning.

To date, deep learning-based detection of optic disc abnormalities in color fundus photographs has mostly been limited to the field of glaucoma. However, many life-threatening systemic and neurological conditions can manifest as optic disc abnormalities. In this study, we aimed to extend the application of deep learning (DL) in optic disc analyses to detect a spectrum of nonglaucomatous optic neuropathies. Using transfer learning, we trained a ResNet-152 deep convolutional neural network (DCNN) to distinguish between normal and abnormal optic discs in color fundus photographs (CFPs). Our training data set included 944 deidentified CFPs (abnormal 364; normal 580). Our testing data set included 151 deidentified CFPs (abnormal 71; normal 80). Both the training and testing data sets contained a wide range of optic disc abnormalities, including but not limited to ischemic optic neuropathy, atrophy, compressive optic neuropathy, hereditary optic neuropathy, hypoplasia, papilledema, and toxic optic neuropathy. The standard measures of performance (sensitivity, specificity, and area under the curve of the receiver operating characteristic curve (AUC-ROC)) were used for evaluation. During the 10-fold cross-validation test, our DCNN for distinguishing between normal and abnormal optic discs achieved the following mean performance: AUC-ROC 0.99 (95 CI: 0.98-0.99), sensitivity 94% (95 CI: 91%-97%), and specificity 96% (95 CI: 93%-99%). When evaluated against the external testing data set, our model achieved the following mean performance: AUC-ROC 0.87, sensitivity 90%, and specificity 69%. In summary, we have developed a deep learning algorithm that is capable of detecting a spectrum of optic disc abnormalities in color fundus photographs, with a focus on neuro-ophthalmological etiologies. As the next step, we plan to validate our algorithm prospectively as a focused screening tool in the emergency department, which if successful could be beneficial because current practice pattern and training predict a shortage of neuro-ophthalmologists and ophthalmologists in general in the near future.

A Case Report on Reversible Toxic Optic Neuropathy on Long Term Treatment of Linezolid in Extensively Drug-Resistant Tuberculosis Patient

We describe a case of Linezolid-induced severe toxic optic neuropathy in a patient with drug-resistant tuberculosis. Linezolid produced severe toxic optic neuropathy in some who used it for a long time. To the best of our knowledge, the optic neuropathy was completely reversed after omitting Linezolid which is one of the effective drug regimens in his prescription, with significant improvements in eye vision.

Intoksikasi Alkohol Akibat Minuman Keras Oplosan

The incidence of alcoholic liquor poisoning (alcoholic liquor) in Indonesia shows a high number. One of the causes of alcohol poisoning is methanol. Methanol poisoning in Indonesia usually occurs as a result of drinking mixed alcohol liquor. It has been reported a male 23 years old with decreased consciousness after drinking oplosan alcohol suspected to contain methanol. The examination reveals that patients has metabolic acidosis, toxic optic neuropathy (TON) and erosive gastritis. Treatment was acidosis correction, prevent formation of metabolites, hemodialysis with supportive and symptomatic teraphy .Keywords: methanol, poisoning, alcohol mixed liquor

Neuro-ophthalmic manifestations of tuberculosis.

Neuro-ophthalmic features are a known association in tuberculosis, especially common in central nervous system tuberculosis (CNS-TB). They are mostly the result of the visual pathway and/or ocular motor and other cranial nerve involvement. Furthermore, toxic optic neuropathy and paradoxical response to anti-tubercular drugs (ATT) are also not uncommon. The etiopathogenesis is by the complex interplay of various factors like exudates, vasculitis, arachnoiditis, presence of tuberculomas, hydrocephalus, brain infarcts and/or immune-mediated reaction. The entity often poses a diagnostic dilemma for the ophthalmologists/neuro-ophthalmologists and may lead to irreversible vision loss. The presence of neuro-ophthalmic features not only affect the visual outcome but are also predictors of systemic morbidity of the disease. Therefore, understanding and knowledge about this entity are necessary for the comprehensive management of the disease. While various forms of TB including CNS-TB have been well-dealt with in literature, little is discussed specifically about the neuro-ophthalmic manifestations of tuberculosis. Therefore, the purpose of this review is to highlight current understanding of the types of neuro-ophthalmic involvement in tuberculosis, its etiopathogenesis, diagnosis and management.

Reversible Nutritional Deficiency-Related Conjunctival Xerosis and Optic Neuropathy Secondary to an Exclusively Potato-Based Diet.

Reversible Nutritional Deficiency-Related Conjunctival Xerosis and Optic Neuropathy Secondary to an Exclusively Potato-Based Diet.

Are the patients with drug sensitive tuberculosis screened for ocular manifestations? A five year analysis from a medical college hospital of Karnataka, India

BackgroundEarly diagnosis and prompt treatment may be sight-saving in patients with Ocular Tuberculosis (TB). Patients on anti tubercular treatment (ATT) also need ophthalmological examination at the start of the treatment and monitoring for toxic optic neuropathy regularly till the completion of treatment. This study is a situation analysis of the referral rates to ophthalmologist and clinical presentations of ocular TB among patients admitted with drug sensitive tuberculosis (DS TB). MethodsA five year record analysis (2013–2017) of patients admitted with DS TB in a medical college hospital setting was done. Demographic and clinical presentations of the patients were recorded. The details about the referral, clinical findings, any possible risk associated with ocular TB and ocular side effects of ATT were noted. Data was entered in Microsoft excel and analysed for descriptive statistics. ResultsAmong 225 inpatients, only 72 (32%) patients were referred to ophthalmologist. The referral rates increased over the period of five years. Intra ocular TB was diagnosed among 11 (15.3%) patients. Only 5 patients among these had complained of reduced vision and others were asymptomatic. ConclusionThe referral of DS TB patients to ophthalmologist was sub optimal. All the DSTB cases need ophthalmic evaluation keeping in mind the possibility of ocular TB and also the adverse effects of ATT.

SPECTRUM OF OPTIC NEUROPATHIES PRESENTING IN NEUROOPHTHALMOLOGY CLINIC AT AFIO

Objective: To study the spectrum of optic neuropathies in patient’s presenting at AFIO Rawalpindi.
 Study Design: Descriptive study/retrospective study.
 Place and Duration of Study: Armed Forces Institute of Ophthalmology, Rawalpindi, from Jan 2017 to Dec 2017.
 Methodology: Retrospective analysis of hospital record of patients coming to neuro-ophthalmic clinic of ArmedForces Institute of Ophthalmology (AFIO), Rawalpindi, from Jan to Dec 2017 was done. Only patients with clearfinal diagnosis of neurophthalmic disease were included. Those with vague diagnosis were excluded. Data wasentered in SPSS version 22 and grouped into variables before analysis. Chi-square test was used for statisticalanalysis. The p<0.05 was considered significant.
 Results: Forty-five patients were included in study including 33 (73.3%) males and 12 (26.6%) females. Mean age of patients was 41.64 ± 17.74 years. Patients were grouped into ischemic optic neuropathy 20%, toxic optic neuropathies 20%, compressive optic neuropathies 17.7%, inflammatory optic neuropathies 11%, neuroretinitis 6.7%, hereditary optic neuropathies 6.7%, multiple sclerosis (MS) related 4.4%, neuromylitis optics spectrum (NMO-SD) related 4.4%, traumatic optic neuropathies 4.4% and nutritional optic neuropathies 4.4%. Deficiency of vitamin B12 and vitamin D was strongly associated with nutritional optic neuropathies while raised TLC was most common association with inflammatory optic neuropathies (57.14%) and of neuroretinitis (66%). Anti-tuberculosis drugs were most common cause of toxic optic neuropathies (88.88%). Chi square test was used for statistical analysis and p<0.05 was considered significant.
 Conclusion: Ischemic optic neuropathy is the most common presentation in our population according to ourstudy. However...........

Tacrolimus-induced optic neuropathy: A case report

Intrduction. Tacrolimus (fujimycin or FK506) is a potent immunosuppressive drug with growing usage. It is usually used in prevention of transplanted organ rejection. Its use is highly valuable, but like other immunosupressants, it has adverse effects. One of them is optic neuropathy. Case report. A 47-year-old white male patients who had received tacrolimus therapy for nine years, after kidney transplantation, developed a subacute, painless vision loss on both eyes. He was thoroughly examined on different possible optic neuropathies and other causes of vision loss. After exclusion of other possible causes, the diagnosis of toxic optic neuropathy was established. His therapy was converted to cyclosporine, by his nephrologist, but his vision had improved only slightly. Conclusion. Toxic optic neuropathies are presented in everyday ophthalmological practice, but they are underestimated. Diagnosis can be demanding, especially when it comes to drugs and substances whose possible toxic effect on the optic nerve is not widely known. Unlike other adverse effects of tacrolimus therapy on nervous system, optic neuropathy can causes great and permanent functional impairment.

OCULAR ANATOMY AND PATHOLOGY IN LUMHOLTZ'S TREE-KANGAROO (DENDROLAGUS LUMHOLTZI).

Lumholtz's tree-kangaroo (Dendrolagus lumholtzi) is one of two species of tree-kangaroos found in Queensland, Australia. There is little information about ocular anatomy and pathology in any species of tree-kangaroo, and there are claims of blindness from unknown causes in free-ranging Lumholtz's tree-kangaroos. This study investigated ocular anatomy and pathology in 80 individuals, using examination of 31 live animals and histopathologic examination of eyes from 49 carcasses. Tree-kangaroos were found to have a typical vertebrate eye with immuno-histochemical evidence for dichromatic color vision. Only 5.4% of animals had evidence of pathology from traumatic injury, infection, or a variety of nonspecific lesions. Toxoplasmosis was implicated in ocular lesions in three animals. This study did not find evidence of widespread blindness in free-ranging animals nor evidence of toxic optic neuropathy. Examinations of live animals highlighted the need to establish normal ocular examination parameters and vision testing protocols suitable for use in tree-kangaroos and the need for more comprehensive examination and testing of animals thought to have vision loss of unknown origin.

Tobacco-Alcohol Amblyopia: Combined Toxic and Nutritional Optic Neuropathy

Vitamin deficiencies of B12 (cobalamin) and B9 (folic acid) are common causes of nutritional optic neuropathy. We present a unique case report of a patient with normal B12 levels and deficient folic acid levels. Folic acid deficiency, along with excessive alcohol and tobacco use, resulted in decreased visual acuities and paracentral visual fields defects. A 57-yearold male experienced a bilateral, insidious, and painless decrease in vision over a two-month period and was found to have tobacco-alcohol amblyopia (TAA), an optic neuropathy related to nutritional deficiency in combination with excessive tobacco use and/or alcohol (ethanol) consumption. With proper supplementation, he experienced significant improvement in vision, but with a devastating outcome leading to his death. This case report illustrates a unique case of folic acid deficiency contributing to TAA, as vitamin B12 deficiency is more frequently associated with TAA. CE Notification: This course is expired.

Acute nutritional optic neuropathy following bariatric surgery

Given the increasing incidence of obesity, bariatric procedures are gaining attention during the past decades, being one of the most effective methods of long-term weight loss. Nutritional optic neuropathy (NON) following bariatric surgeries is a rare but devastating complication caused by a complete lack or inadequate supply of nutrients for the normal function of nerve fibers. We report a case of bilateral anterior NON after a Single Anastomosis Duodenoileal Bypass with Sleeve Gastrectomy, and present a review of the literature about neuro-ophthalmic complications associated with these procedures. Bariatric surgery may constitute an established risk factor for NON and both patient and physician have to be aware of the importance of closely monitoring vitamin depletions and neurologic and visual symptoms.

RESEARCH OF REPARATIVE MECHANISMS IN THE OPTIC NERVE IN TOXIC NEUROPATHY CAUSED BY Cr (VI)

Intoxication lesions of the optic nerve (toxic optic neuropathy, TON) most often occur under the influence of exogenous factors, including heavy metals. Сell survival under stress have involves heat shock proteins (HSPs). The aim of the research. To assess the optic nerve’s immunoreactivity to heat shock proteins of the HSP70 and HSP90α families and reveal its relationship with the severity of morphological changes in toxic optic neuropathy caused by Cr (VI). Materials and methods. The study was conducted on 48 mature male rats. The experimental groups were given to drink water with Cr(VI) for 20, 40 and 60 days. This type of water is typical for the water basins in the northern districts of the Sumy region. Optic nerves сhanges under the influence of Cr(VI) have investigated by the morphometric method. Neuroglial cells and capillary endothelial cells were assessed by immunohistochemistry by HSP70α and HSP90 expression for intensity and spatial distribution. Results. The data analysis revealed that Cr (VI) has a neurotoxic effect on the optic nerve with the development of edema, which is manifested by the thickening of nerve fibers. The dynamics of HSP70 immunoexpression in the endothelium of the optic nerve capillaries of rats on 20 and 40 experimental days was characterized by stable values and was 1.5 times higher than the control. The maximum number of positively stained cells for the HSP70 marker was detected in endothelial cells of the microvasculature for 60 days – 82.44±12.42 %. HSP70 levels in neuroglia cells of optic nerve have decreased on day 40 (55.66±11.56% p=0.05) and lower than the control (70.44±4.81 %.) group. Optic nerve capillaries was highest immunoactivity on HSP90 in group II endothelial cells – 51.22±14.57% (p=0.05). The activity of HSP90α protein in optic neuroglia cells was characterized by a gradual increase in the duration of the experiment and was higher by 12, 4 % in experimental group III (81.77±21.67 %) compared with control (71.66±4.95 %). Conclusions. Our study provides an insight into the significant difference in the immunoreactivity of heat shock proteins of the HSP70 and HSP90α families in neuroglia and endothelial cells of the optic nerve capillaries under the influence of Cr(VI). The results obtained suggest that Cr (VI) has a neurotoxic effect on the optic nerve with the development of edema, which is manifested by the thickening of nerve fibers. A comparison of the dynamics of the development of the dystrophic process in the optic nerve with the results of the immunohistochemical analysis showed, that an increase in the thickness of nerve fibers is accompanied by an increase in immunoreactive neuroglial cells (HSP90α) and endothelial cells (HSP70).

Evaluation of the choroidal thickness and retinal nerve fiber layer and visual fields in morbid obesity: Does bariatric surgery affect retinal structure and function?

Purpose:The study aimed to investigate the changes in choroidal thickness (CT), retinal nerve fiber layer thickness (RNFL), and visual field parameters in morbidly obese patients following bariatric surgery.Methods:The study included 40 morbidly obese patients with body mass indexes (BMI) ≥40 who had undergone bariatric surgery (Group 1) and 40 age-and sex-matched healthy subjects with normal BMI values (Group 2). RNFL and CT measurements by optical coherence tomography (OCT) and visual field test were performed preoperatively and the 1st, 6th, and 12th months postoperatively. CT measurements were obtained from the subfoveal, nasal (N), and temporal (T) regions at distances of 500 μm and 1,000 μm from the fovea.Results:No significant pathology was detected during ophthalmological examinations following bariatric surgery. The BMIs were found to be significantly lower in all of the periods after bariatric surgery (P < 0.0001). The CT measurements decreased significantly in all periods after bariatric surgery (P < 0.0001). No differences were found in terms of the mean RNFL thicknesses in all postoperative periods (P = 0.125). Visual field tests showed no significant changes during scheduled visits. (P = 0.877). No visual field defect was detected in any patient during the follow-up periods after bariatric surgery.Conclusion:These results have suggested that CT is positively correlated with BMI and decreased with a reduction in BMI progressively. Nutritional disorders resulting from malabsorption have not caused any nutritional optic neuropathy and visual field defect for at least the first postoperative year after bariatric surgery.

Late-stage sequela of an isolated optic neuropathy after acute magnesium valproate overdose: A case report.

Magnesium valproate is a valproic acid (VPA) derivative that is widely used for the treatment of epilepsy and bipolar disorders. Acute overdose of VPA may cause complicated systemic syndromes; however, the reports of ocular sequelae caused by toxic optic neuropathy (TON) are rare. We present a case of a 19-year-old female with bilateral damage to visual function after acute VPA overdose. She was comatose and received systemic treatments for 1 month, during which she suffered a substantial loss of visual function without any evident neurological sequelae. The first recorded visual acuity was no light perception in the right eye (OD) and hand motion in the left eye (OS). Her best-corrected visual acuity improved to 20/100 OS after 4 months of hyperbaric oxygen therapy and neurotrophic treatments. Her visual field was limited to an inferior nasal area OS. Therefore, a diagnosis of TON was made. Her visual function remained stable in the left eye, but did not recover in the right eye during the 5-month follow-up. We found damage to the optic nerve pathway during ophthalmic examinations. We report a rare case of TON caused by acute VPA overdose. Hyperbaric oxygen therapy, and neuroprotective and neurotrophic treatments might be effective at the early stage but cannot fully reverse the damage to the optic nerve. The present case indicates the potential neurotoxicity of VPA. It is crucial to determine the severity of an isolated optic nerve sequela caused by VPA overdose, though it might be rare as observed in previous reports. Further confirmation of the likelihood of its causation and its pathophysiology is needed in the future.

Choroidal Neovascularization and Toxic Optic Neuropathy Secondary to Tobacco Use: A Case Report

Tobacco and alcohol dependence are known to cause choroidal neovascularization and toxic optic neuropathy, although these typically occur in isolation. In this case report, we describe a 54-year-old male who presented with a juxtafoveal choroidal neovascular membrane (CNVM) in the left eye. Over the course of the next two years, his vision worsened significantly in both eyes, and he developed decreased color vision and paracentral scotomas. Impaired photoreceptor response was detected on full-field electroretinography in both eyes. MRI of the brain and orbits was normal, and laboratory tests for optic neuropathy were within normal limits, except for highly elevated cotinine and nicotine levels. He was in the habit of chewing tobacco nearly constantly, and he admitted to drinking 15-20 alcoholic beverages per week. He was diagnosed with choroidal neovascularization and optic atrophy due to tobacco and alcohol overuse. The effects of tobacco and alcohol use on the health of the choroidal vasculature and optic nerve are discussed in the article.

Ischemic Optic Neuropathy Caused by Iron Deficiency Anemia Accompanied by Ethambutol-induced Toxic Optic Neuropathy

ëª©ì  에탐부톨에 의한 ì‹œì‹ ê²½ë³‘ì¦ê³¼ ì² ê²°í•ì„± 빈혈에 의한 ì‹œì‹ ê²½ë³‘ì¦ì´ 동반된 1예를 ë³´ê³ í•˜ê³ ìž 한다. 증례요약 64세 여자 환자가 한 달 ì „ë¶€í„° 서서히 시작된 양안의 무통성 ì‹œë ¥ì €í•˜ë¥¼ 주소로 내원하였다. 4개월 ì „ë¶€í„° 결핵 치료를 위해 에탐부톨을 매일 복용 중이었다. êµì •ì‹œë ¥ì€ 양안 0.3으로 ì¸¡ì •ë˜ì—ˆìœ¼ë©°, 시야검사상 양안 중심시야 결손이 관찰되었다. 색각검사는 우안 3개, 좌안 2개를 맞추었다. 에탐부톨 복용으로 인한 ë ì„± ì‹œì‹ ê²½ë³‘ì¦ 의심하 약물 복용을 바로 중단하였으나, êµì •ì‹œë ¥ì€ ì ì°¨ ì• í™”ë˜ì–´ 우안 0.05, 좌안 ì•ˆì „ìˆ˜ì§€ 50 cm로 떨어졌다. 환자의 혈액검사 ê²°ê³¼ ì² ê²°í•ì„± 빈혈 소견을 보여 치료를 ì‹œìž‘í•˜ì˜€ê³ , 5개월 후 혈액검사 ê²°ê³¼ ì •ìƒìœ¼ë¡œ íšŒë³µë˜ê³ êµì •ì‹œë ¥ 양안 0.5까지 í˜¸ì „ë˜ì—ˆìœ¼ë‚˜, 빛간섭단층촬영상 ì‹ ê²½ì ˆì„¸í¬-속얼기층의 손상이 관찰되어 추후 ì§€ì†ì ì¸ 경과 관찰 ì˜ˆì •ì´ë‹¤. ê²°ë¡ ì² ê²°í•ì„± 빈혈에 의한 í—ˆí˜ˆì‹œì‹ ê²½ë³‘ì¦ì€ 단기간에 ë°œìƒí• ìˆ˜ 있으며, 에탐부톨에 의한 ë ì„± ì‹œì‹ ê²½ë³‘ì¦ê³¼ 동반되어 감별이 ì–´ë ¤ìš¸ 수 있다. ì ì§„ì  ì‹œë ¥ì €í•˜ë¡œ 오는 환자들의 경우, ëª í™•í•œ ì‹œë ¥ì €í•˜ì˜ 요인이 있더라도 다각도로 평가하여 ì‹ ì†ížˆ ì§„ë‹¨í•˜ê³ ì¹˜ë£Œí•˜ëŠ” 것이 중요하다. Keywords: Ethambutol, Iron deficiency anemia, Ischemic optic neuropathy, Toxic optic neuropathy

Food Aversion Leading to Nutritional Optic Neuropathy in a Child With Severe Vitamin A Deficiency.

Food Aversion Leading to Nutritional Optic Neuropathy in a Child With Severe Vitamin A Deficiency.

Nutritional Optic Neuropathy due to Folic Acid Deficiency

ëª©ì  엽산 부족으로 발생한 ì˜ì–‘ê²°í•ì‹œì‹ ê²½ë³‘ì¦ê³¼ 엽산의 경구 보충으로 회복된 환자를 ë³´ê³ í•˜ê³ ìž 한다. 증례요약 45세 남자가 1개월 ì „ë¶€í„° 무통성의 양안 ì‹œë ¥ì €í•˜ì™€ 색깔 구분이 잘 안 된다는 것을 주소로 본원에 의뢰되었다. ì „ì•ˆë¶€, 망막에 이상 소견은 ì—†ì—ˆê³ ë™ê³µë°˜ì‘ê²€ì‚¬ìƒ 좌안에 êµ¬ì‹¬ë™ê³µìš´ë™ìž¥ì• ê°€ 관찰되었다. 시야 검사상 양안에 ì¤‘ì‹¬ì•”ì ì´ ê´€ì°°ë˜ì—ˆê³ í•œì‹ìƒ‰ê°ê²€ì‚¬ìƒ 양안 ì „ìƒ‰ë§¹ì´ì—ˆë‹¤. 환자는 10ë „ê°„ 알코올 ì¤‘ë ì†Œê²¬ì´ 있었으며 최근에 식사를 자주 ê±¸ë €ë‹¤ê³ í•˜ì˜€ë‹¤. 혈액검사상 엽산 부족으로 경구 엽산을 ì²˜ë°©í•˜ì˜€ê³ ê²½êµ¬ 엽산 복용 6주 후 환자의 증상과 시야검사, 한식색각검사 소견이 회복되었다. ê²°ë¡ ì•„ì§ 국내에는 ë³´ê³ ëœ 바가 없는 엽산 부족으로 인한 ì‹œì‹ ê²½ë³‘ì¦ì„ ê²½í—˜í•˜ì˜€ê³ , 경구 엽산의 복용으로 시기능이 í˜¸ì „ë˜ì—ˆê¸°ì— 이를 ë³´ê³ í•œë‹¤. Keywords: Folic acid, Nutritional optic neuropathy

Nutritional Optic Neuropathies: State of the Art and Emerging Evidences.

Nutritional optic neuropathy is a cause of bilateral, symmetrical, and progressive visual impairment with loss of central visual acuity and contrast sensitivity, dyschromatopsia, and a central or centrocecal scotoma. The clinical features are not pathognomonic, since hereditary and toxic forms share similar signs and symptoms. It is becoming increasingly common due to the widespread of bariatric surgery and strict vegetarian or vegan diets, so even the scientific interest has recently increased. In particular, recent studies have focused on possible pathogenetic mechanisms, and on novel diagnostic and therapeutic strategies in order to prevent the onset, make a prompt diagnosis and an accurate nutritional supplementation, and to avoid irreversible optic nerve atrophy. Nowadays, there is clear evidence of the role of cobalamin, folic acid, thiamine, and copper, whereas further studies are needed to define the role of niacin, riboflavin, and pyridoxine. This review aims to summarize the etiology, diagnosis, and treatment of nutritional optic neuropathy, and it is addressed not only to ophthalmologists, but to all physicians who could come in contact with a patient with a possible nutritional optic neuropathy, being a fundamental multidisciplinary approach.

Prospective study to evaluate incidence and indicators for early detection of ethambutol toxicity

AimsTo evaluate incidence of toxic optic neuropathy in patients receiving ethambutol (EMB) for 6 months and to identify its early indicators.MethodsWe included 50 patients on anti-tubercular therapy (ATT) including EMB...