Ocular manifestations and complications of acute methyl alcohol intoxication

The ocular manifestations of acute methyl alcohol intoxication were studied in 24 men during an outbreak in Port Moresby, Papua New Guinea. The visual acuity, pupillary reactions to light, fundal appearances and visual fields were recorded in all patients within 72 hours of ingestion of methanol and again three months later. Three groups were identified. Nine patients had no ocular abnormality (Group 1). Seven patients had only transient ocular abnormalities (Group 2). Eight patients had permanent ocular abnormalities (Group 3). Transient abnormalities included peripapillary oedema, optic disc hyperaemia, diminished pupillary reactions to light, and central scotomata. Permanent ocular abnormalities included optic disc pallor, attenuation of arterioles, sheathing of arterioles, diminished pupillary reaction to light, diminished visual acuity, central scotomata, and other nerve fibre bundle defects. Complete blindness occurred in two patients, while severe visula deficit resulted in four others. The incidence of permanent ocular abnormalities was found to correlate with the incidence of metabolic acidosis (P less than 0.01), and with the stated volume of methanol consumed (P less than 0.05). An inverse correlation was found between stated volume of methanol consumed and onset of blurred vision. The difficulties in management and rehabilitation of these patients are discussed.