Influence of chronic alcohol abuse and ensuing forced abstinence on static subjective accommodation function in humans

Abstract

Purpose. Acute alcohol ingestion can change accommodation, but the long term effects of sustained alcohol consumption on accommodative function have not been studied in detail. This study was thus undertaken on individuals with a history of alcohol abuse.Methods. Thirty-seven male individuals aged 25–56 years (average 40 years) from an alcohol rehabilitation centre in Inverness, Scotland, were assessed on admission and after a week of forced abstinence. The results were compared to a paired age-matched set of control male subjects. The static amplitude of accommodation was measured by an RAF rule, and the pupil size measured with a pupil gauge.Results. On admission, the group mean measured amplitude of accommodation was 4.7±2.2D (mean±SD). These values for the alcoholics were lower than age-matched controls (of 5.9±2.9D). The slope of the age-dependent decline in RAF rule accommodation measures was significantly smaller for the alcoholics compared to controls (at 0.215±0.027D/year versus 0.332±0.015D/year, respectively; p<0.001), with the younger alcoholics showing a greater impairment. Following abstinence, there was no measurable change in accommodation measured, indicating the lower amplitude in the alcoholics was not attributable to circulatory alcohol levels. The resting pupil diameter in the alcoholics was 4.37±0.63mm compared to the controls of 3.97±0.75mm, with a higher incidence of small pupils (≤3mm) in the controls.Conclusions. The results indicate that chronic alcohol use can adversely affect subjective static accommodation, especially in younger alcoholics, as well as cause slight mydriasis.