Abstract
Purpose: :
To measure the acute effect of drinking a high dose alcohol on mesopic rod and cone critical fusion frequency (CFF) and explore the association between acute alcohol impairment on photoreceptor function and recent drinking patterns.
Methods: :
The study examined 16 young healthy non-alcoholic participants (age: 27.1±5.6 years, 7 women and 9 men). Daily alcohol drinking in the past month was estimated from the timeline follow-back calendar. Each subject completed two randomized sessions (0.8 g/kg alcohol, or a placebo). Each session consisted of CFF measurement at baseline (Pre) and at 45 minutes after the beverage consumption (Post). Isolated rod or cone modulation (35% contrast, 80 Td) was generated in a four-primary photostimulator that can independently control rod and cone stimulations. The stimuli (2° circular field within a 6° surround) was presented at 6.5° eccentricity. The difference in CFFs at the two time points (Pre-Post) was used to quantify the beverage effect.
Results: :
Compared with placebo, alcohol significantly reduced cone CFFs (alcohol vs placebo: 0.88±1.80 vs -0.84 ±1.74 Hz, p=.02) and rod CFFs (2.10±2.08 vs -0.62 ±1.82 Hz, p<.001). Factor analysis of past-month drinking days, average drinks on drinking days, binge drinking days (consuming 5+ drinks/occasion for men and 4+ for women) and maximum drinks/occasion revealed one factor accounted for 93% of variance in the past-month drinking pattern. For those who had engaged in binge drinking at least twice in the past month (N = 10), the drinking factor score was significantly correlated to overall alcohol effect [alcohol (Pre-Post)-placebo (Pre-Post)] on cone CFF (r = 0.690, p = 0.027) but not on rod CFF (r = 0.36, p = 0.335). No significant association between overall alcohol effect and drinking pattern was observed among those who had no binge drinking (N = 6).
Conclusions: :
An intoxicating dose of alcohol acutely impaired both rod and cone CFFs and a heavier drinking pattern was associated more alcohol impairment on cone CFFs among those who engaged binge drinking. The acute alcohol results may help to understand the mechanisms for how chronic heavy alcohol consumption increases the likelihood of developing some retinal diseases that involve photoreceptor function loss.
Keywords: photoreceptors • photoreceptors: visual performance • temporal vision