Acute methanol poisoning harms the optic nerve and central nervous system, can cause irreversible damage, even coma or death in severe cases. This article reported four cases of methanol poisoning. 3 patients mistakenly ingested industrial alcohol containing methanol, the most serious patient suffered from coma, vision loss and other symptoms, the blood methanol concentration was 869.3 μg/ml. Another patient was poisoning caused by inhalation of methanol, with symptoms such as total blindness in the right eye and decreased visual acuity in the left eye. After active supportive treatment, 2 patients had partial recovery of visual acuity, and 2 patients had no sequelae. This article discussed the clinical features, treatment and prognosis of optic nerve damage caused by methanol poisoning, in order to raise awareness of this disease.
Coma ; Follow-Up Studies ; Humans ; Methanol ; Optic Nerve ; Optic Nerve Injuries ; Poisoning/therapy*

BACKGROUND: Methyl alcohol poisoning in mobile phone–manufacturing factories during 2015–2016 was caused by methyl alcohol use for cleaning in computerized numerical control (CNC) processes. To determine whether there were health complications in other workers involved in similar processes, the Occupational Safety and Health Research Institute conducted a survey. METHODS: We established a national active surveillance system by collaborating with the Ministry of Employment and Labor and National Health Insurance Service. Employment and national health insurance data were used. Overall, 12,048 employees of major domestic mobile phone companies and CNC process dispatch workers were surveyed from 2016 to 2017. We investigated methyl alcohol poisoning by using the national health insurance data. Questionnaires were used to investigate diseases due to methyl alcohol poisoning. RESULTS: Overall, 24.9% of dispatched workers were employed in at least five companies, and 23.9% of dispatched workers had missing employment insurance history data. The prevalence of blindness including visual impairment, optic neuritis, visual disturbances, and alcohol toxicity in the study participants was higher than that reported in the national health insurance database (0.02%, 0.07%, 0.23%, and 0.03% versus 0.01%, 0.07%, 0.13%, and 0.01%, respectively, in 2015). Moreover, 430 suspicious workers were identified; 415 of these provided an address and phone number, of whom 48 responded (response rate, 11.6%). Among the 48 workers, 10 had diseases at the time of the survey, of whom 3 workers were believed to have diseases related to methyl alcohol exposure. CONCLUSION: This study revealed that active surveillance data can be used to assess health problems related to methyl alcohol poisoning in CNC processes and dispatch workers.
Academies and Institutes ; Blindness ; Cell Phones ; Employment ; Insurance ; Mass Screening ; Methanol ; National Health Programs ; Occupational Diseases ; Occupational Health ; Optic Neuritis ; Poisoning ; Prevalence ; Vision Disorders

Methanol poisoning results in neurological complications including visual disturbances, bilateral putaminal hemorrhagic necrosis, parkinsonism, cerebral edema, coma, or seizures. Almost all reported cases of methanol poisoning are caused by oral ingestion of methanol. However, recently there was an outbreak of methanol poisoning via non-oral exposure that resulted in severe neurological complications to a few workers at industrial sites in Korea. We present 3 patients who had severe neurological complications resulting from non-oral occupational methanol poisoning. Even though initial metabolic acidosis and mental changes were improved with hemodialysis, all of the 3 patients presented optic atrophy and ataxia or parkinsonism as neurological complications resulting from methanol poisoning. In order to manage it adequately, as well as to prevent it, physicians should recognize that methanol poisoning by non-oral exposure can cause neurologic complications.
Acidosis ; Ataxia ; Brain Diseases, Metabolic ; Brain Edema ; Coma ; Eating ; Humans ; Korea ; Methanol* ; Necrosis ; Neurologic Manifestations ; Optic Atrophy ; Parkinsonian Disorders ; Poisoning* ; Renal Dialysis ; Seizures

PURPOSE: The purpose of this study is to evaluate the effectiveness and adverse effect of fomepizole in the management of acute ethylene glycol or methanol poisoning in children. METHODS: Databases such as PubMed, Embase, Cochrane library, and KoreaMed were searched using terms related to fomepizole, ethylene glycol, methanol and pediatric. All studies, regardless of study design, reporting effectiveness or safety endpoints in children were included. Reference citations from identified publications were reviewed. Only reports written in English or Korean languages were included. The reference search was performed by two authors. RESULTS: Twenty-two relevant literatures were finally included. They were one narrative review, 4 retrospective case series, and 17 case reports (19 cases). Case reports were classified as 5 fomepizole only, 8 fomepizole with other therapies, and 6 no fomepizole. All patients from the literatures were fully recovered without long term sequelae. Adverse effects of fomepizole were reported including anaphylaxis, thrombophlebitis and nystagmus. CONCLUSION: There are insufficient literatures regarding fomepizole treatment in children with ethylene glycol or methanol poisoning. The benefits or harms are not clearly established based on the clinical evidences. More prospective comparative studies are required in the future.
Anaphylaxis ; Child* ; Ethylene Glycol* ; Humans ; Methanol* ; Pediatrics ; Poisoning* ; Prospective Studies ; Retrospective Studies ; Thrombophlebitis

BACKGROUND: Methyl alcohol poisoning has been mainly reported in community. Two cases of methyl alcohol poisoning occurred in a small-sized subcontracted factory which manufactured smartphone parts in Korea. CASE PRESENTATION: One young female patient presented with dyspnea and visual disturbance. Another young male patient presented with visual disturbance and myalgia. They treated with sodium bicarbonate infusion and hemodialysis for metabolic acidosis. In addition, he received ethyl alcohol per oral treatment. Her and his urinary methyl alcohol concentration was detected as 7.632 mg/L, 46.8 mg/L, respectively, although they were treated hemodialysis. Results of the working environment measurement showed that the concentration of methyl alcohol (1030.1–2220.5 ppm) in the air exceeded the time weighted average (200 ppm). They were diagnosed with optic neuropathy due to methyl alcohol poisoning and still have visual impairment. CONCLUSIONS: Workers who hired as dispatched employees in a small-sized subcontracted factory were exposed to high concentrations of methyl alcohol. The workplace had poor ventilation system. In addition, workers did not wear proper personal protect equipment. Working environment measurement and annual chekups for workers were not performed. They were in a blind spot to occupational safety and health. More attention is needed to protect vulnerable workers’ health.
Acidosis ; Aluminum* ; Dyspnea ; Ethanol ; Female ; Humans ; Inhalation* ; Korea ; Male ; Methanol* ; Myalgia ; Occupational Health ; Optic Disk ; Optic Nerve Diseases ; Poisoning ; Renal Dialysis ; Smartphone ; Sodium Bicarbonate ; Ventilation ; Vision Disorders

Methanol poisoning is a medical emergency that requires rapid elimination of the toxin and its metabolites for recovery. The danger of methanol results from the accumulation of its toxic metabolite formic acid. This accumulation may result in the development of metabolic acidosis, visual impairment, and damage to the basal ganglia. Extracorporeal treatment is recommended in severe cases of methanol poisoning with coma, seizure, new vision deficits, metabolic acidosis, high serum anion gap, elevated methanol concentrations or impaired kidney function. Although the serum methanol concentration is helpful in determining the use of extracorporeal treatment, methanol assays are not standard laboratory tests in Korea. Herein, we report a case of methanol poisoning in which the patient's clinical improvement was confirmed using serum and urine methanol levels.
Acid-Base Equilibrium ; Acidosis ; Basal Ganglia ; Coma ; Emergencies ; Extracorporeal Circulation ; Kidney ; Korea ; Methanol* ; Osmolar Concentration ; Poisoning* ; Renal Replacement Therapy* ; Seizures ; Vision Disorders

OBJECTIVE: To investigate concentration and distribution in blood and tissues of formic acid after methanol intoxication in rats. METHODS: The Sprague-Dawley rats were divided into groups for control group and 3-day and 7-day intoxication treatment groups. The experimental groups were administered methanol by gavage with the initial dose of 8 mL/kg and followed with 4 mL/kg supplemental dose 24 h later. After 3 days and 7 days later, rats were killed by decapitation. Then samples of cardiac blood, liver, kidney, brain, heart and stomach of each group were collected. Formic acid concentrations were detected by high performance liquid chromatography. RESULTS: Formic acid concentrations in tissues were higher than in blood. Compared with 3-day intoxication group, there was an increase formic acid of concentration in brain and stomach in 7-day intoxication group, while a decrease in liver and kidney (P < 0.05). CONCLUSION High performance liquid chromatography could be used to accurately detect formic acid. As the metabolite of methanol, formic acid accumulates in rat blood and tissues after intoxication and the concentrations in organs and tissues are obviously higher than in blood.
Animals ; Brain/metabolism* ; Chromatography, High Pressure Liquid ; Formates/blood* ; Kidney/metabolism* ; Liver/metabolism* ; Methanol/poisoning* ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution

OBJECTIVE: To study the characters of oscillatory potentials (OPs) of electroretinogram (ERG) after methanol intoxication in rats. METHOD: The SD rat models of methanol intoxication were established and divided into control group, 3-day intoxication group, 7-day intoxication group. The changes of OPs of ERG were recorded in a dark room. RESULTS: The total amplitudes of 3-day and 7-day intoxication groups decreased approximately 50% compared with that of the control group, while the schedule delayed approximately 16% and 61%, respectively. CONCLUSION The characters of methanol intoxication in rats included delay in schedule and decline in the total amplitude of OPs.
Animals ; Electroretinography ; Methanol/poisoning* ; Rats ; Retina/physiopathology*

On February 21, 2013, 6 elderly people collapsed abruptly after eating bean sprout bibimbab (boiled rice mixed with bean sprouts and seasoned with soybean sauce) at a countryside restaurant in the Chungbuk Province, Korea. Minutes after eating the meal, all of the patients lapsed into a state of stupor. Respiratory arrest developed in 2 patients; and one of two patients died of cardiac arrest. The autopsy identified methomyl and methanol in the deceased patient's gastric contents and in the remaining soybeanbean sauce seasoning. Five of the 6 patients ingested one spoonful of the soybeanbean sauce seasoning and survived, while one patient who died of cardiac arrest, ingested approximately two spoons. Symptoms of toxicity presented quickly in the subjects and progressed rapidly, including chest tightness, an unusual sensation in the pit of the stomach, dizziness, ataxia, and finally, collapse. Three patients who drank ethanol with the meal experienced only mild toxic symptoms. Our analysis of the clinical observations in these cases suggests that ingestion of methomyl pesticide and the additive toxicity of methanol may have been responsible for the intoxication.
Aged ; Cholinesterase Inhibitors/poisoning ; *Disease Outbreaks ; Ethanol ; Female ; Foodborne Diseases/*epidemiology ; Humans ; Insecticides/*poisoning ; Male ; Methanol/*poisoning ; Methomyl/*poisoning ; Republic of Korea/epidemiology

In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication, 35 rats were divided randomly into five groups administrated with saline, 3-day high dose, 7-day high dose, 3-day low dose and 7-day low dose methanol separately. The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning. The microstructure and ultrastructure of the retina were observed at the same time. The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning, which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG. These injuries were aggravated 7 days after poisoning. Meanwhile, the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning, but there were no further worsening tendency 7 days after poisoning. The retinal histological analysis showed cellular edema, heteromorphy and disarrangement, tissular loosen of the inner nuclear layer and photoreceptors layer. The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer. The low-dose methanol intoxication only caused transient damage of the retina. Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells. The mitochondrial damage developed from outer layer to inner layer of the retina.
Animals ; Edema/pathology* ; Electroretinography ; Forensic Medicine ; Male ; Methanol/poisoning* ; Mitochondria/pathology* ; Photoreceptor Cells/pathology* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Retina/physiopathology* ; Retinal Cone Photoreceptor Cells/pathology* ; Retinal Diseases/pathology* ; Retinal Rod Photoreceptor Cells/pathology* ; Time Factors