THE EFFECT OF A ‘SOCIAL’ DOSE OF ALCOHOL ON THE CENTRAL RETINAL SENSITIVITY AND FIXATION STABILITY Measured with the scanning laser ophthalmoscope

Purpose: To evaluate the effect of a ‘social’ dose of alcohol on the central retinal sensitivity and fixation stability, measured with microperimetry using scanning laser ophthalmoscopy (SLO). Patients and methods: Eighteen subjects, nine males and nine females, were given alcohol in a ‘social’ dose, corresponding to 40 ml wine/70 kg/30 minutes. Alcohol level, visual acuity (VA), and contrast sensitivity were examined, and central retinal sensitivity and fixation stability were measured with SLO before and after alcohol intake. Results: There were no statistically significant differences in VA, central retinal sensitivity or contrast sensitivity before and after alcohol intake. A significant difference in fixation stability was found before and after alcohol intake. There was no difference between males and females regarding the instability in fixation. Fixation stability was more affected by alcohol in six of the subjects than in the others. Conclusions: The central retinal sensitivity was not consistently affected by a small dose of alcohol. In contrast, the fixation stability significantly deteriorated, and a horizontal instability could be seen. No correlation was found between alcohol level and fixation instability, and the decrease could not be explained by the well-known sex difference in alcohol tolerance, thus the reason for this inter-individual difference could not be determined in the current study. Further investigations are needed to evaluate the relevance of fixation stability for visual function and the reasons for the inter-individual difference in alcohol tolerance.