Abstract
Purpose :
To evaluate how the consumption of alcohol at different two rates can affect night vision.
Methods :
A total of 17 individuals from different ages (30.2±9.5 years) took part in the study. All of them should have a best corrected visual acuity (BCVA) of 1.0 or higher. Three sessions were undergone: the first, under normal conditions, the second (Post 1) with the consumption of 300 ml of red wine (13.5% of alcohol), and the last (Post 2), with the consumption of 450ml of the same wine. We measured the breath-alcohol content (BrAC) and then the sample was divided in two groups: subjects with a BrAC of 0.25 mg/l or lower, and subjects with a BrAC>0.25 mg/l, since 0.25 mg/l is the legal limit for driving in Spain. In these sessions, under low-illumination conditions, we measured the visual-disturbance index (VDI) with the halometer HALO v1.0, the pupil size, and the intraocular straylight using the C-Quant device. The subjects also answered a questionnaire about their night-vision satisfaction.
Results :
For the Post 1 condition, none of the subjects reached 0.25 mg/l, and we found a significant increase of the VDI (p<0.05) compared with normal conditions and an increase of pupil size and straylight, but not significant (p>0.05). In Post 2 conditions, for a BrAC<0.25 mg/l (n=10) we found a significant increase in the VDI in monocular conditions (p<0.05) but not significant under binocular conditions (p>0.05) and similar results for pupil size and straylight (p>0.05). For the group with a BrAC>0.25 mg/l (n=7), we found a significant increase of the VDI and pupil size (p<0.05). The intraocular straylight was also higher, but not significant (p>0.05). Questionnaire results showed a negative correlation with the straylight and VDI results (r<0), signifying that individuals who performed better the visual tasks scored lower on the questionnaire in such a way that they were more demanding with their vision.
Conclusions :
There is a deterioration of night-vision performance after alcohol consumption, especially for BrAC values higher than 0.25 mg/l due to an increase of pupil size, among other factors. As a result, in subjects after drinking a stronger effect of visual halos and intraocular straylight has been demonstrated. Furthermore, as individuals with worse night vision are more satisfied with their vision, the use of questionnaires is not a reliable method to characterize night-vision.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.