Individuals who survive methanol poisoning — typically from ingesting bootleg liquor — appear to suffer lifelong problems with vision and neurological damage, especially if they continue to drink alcohol heavily.

Reuters reported April 2 that a followup study on Estonians who were poisoned by methanol in 2001 found that the effects may be irreversible. Of 86 people who survived the poisoning incident (43 died), 66 seemed to have no lasting problems while 20 did. However, six years afterwards 26 of the survivors had died — often from alcohol poisoning.

Of those who left the hospital with lingering symptoms, 35 percent later died, but so did 29 percent of those who had no symptoms at discharge.

Also, 36 percent of the methanol-poisoning victims had developed new vision or neurological problems, including some who initially appeared to escape unscathed. Individuals who continued to drink heavily were at the highest risk of later developing neurological problems, researchers found.

“Individuals affected by a methanol outbreak may benefit from counseling and other efforts aimed at reducing their alcohol abuse,” said researcher Raido Paasma of Foundation Parnu Hospital in Estonia.

The study was published online in the journal BMC Clinical Psychopharmacology.