Alterações na sensibilidade ao contraste relacionadas à ingestão de álcool

Psychophysical Evaluation of Visual Functions of Ex-Alcoholic Subjects After Prolonged Abstinence

Chronic alcohol abuse can lead to a brain damages, and the health status of alcoholics even after a long-term alcohol abstinence is a public health concern. The present study investigated the color vision and spatial luminance contrast sensitivity of a group of 17 ex-alcoholics (46.3 ± 6.7 years old) in long-term alcohol abstinence after having been previously under alcohol dependence for many years. We also investigated the association of impaired psychophysical performance in different tests we applied. The mean time of alcohol consumption was 16.9 ± 5.1 years and the mean abstinence period was 12.4 ± 8.5 years. Achromatic vision of all subjects was evaluated using spatial luminance contrast sensitivity function (CSF) test and color vision was evaluated using Mollon-Reffin color discrimination test (MR) and the Farnsworth-Munsell 100 hue arrangement test (FM100). Relative to controls, the spatial luminance contrast sensitivity was lower in 10/17 of the ex-alcoholic subjects. In the color vision tests, 11/16 ex-alcoholic subjects had impaired results compared to controls in the FM100 test and 13/14 subjects had color vision deficits measured in the MR test. Fourteen subjects performed all visual tests, three subjects had impaired results for all tests, seven subjects had impaired results in two tests, three subjects had visual deficit in one test, and one had normal results for all tests. The results showed the existence of functional deficits in achromatic and chromatic vision of subjects with history of chronic alcoholism after long abstinence. Most subjects had altered result in more than one test, especially in the color vision tests. The present investigation suggests that the damage in visual functions produced by abusive alcohol consumption is not reversed after long term alcohol abstinence.

Percepção visual de grade senoidal radial após o consumo de álcool

O objetivo deste trabalho foi comparar a percepção visual de contraste de adultos sem a ingestão de álcool e após a ingestão moderada de álcool - 0,09% Blood Alcohol Concentration (BAC), através da Função de Sensibilidade ao Contraste (FSC). Participaram dos experimentos cinco voluntárias, na faixa etária de 21 a 30 anos, com acuidade visual normal ou corrigida. Para medir a FSC, foram usados estímulos de grade senoidal radial de frequências de 0,25; 2 e 8 ciclos por grau de ângulo visual. Utilizou-se um delineamento experimental com medidas repetidas e o método psicofísico da escolha forçada. Os resultados demonstraram efeito significante de participantes (F4, 55 = 25,518; p < 0,001), de frequências (F2, 110 = 172,288; p < 0,001) e de interação entre frequências x condições x participantes (F8, 110 = 26,806; p < 0,001). Este estudo preliminar sugere alterações na FSC relacionadas à ingestão moderada de álcool.