The electro-oculographic responses to alcohol and light in a series of patients with retinitis pigmentosa.

PURPOSE Alcohol produces changes in the electro-oculogram (EOG) similar to those caused by light, but indirect evidence indicates that alcohol directly affects the retinal pigment epithelium (RPE). An investigation of the alcohol-induced increase (termed the alcohol rise in this study) in patients with disease of the photoreceptors was therefore of interest. METHODS Standard EOGs were recorded after oral administration of alcohol in a group of patients with retinitis pigmentosa (RP). RESULTS The average response of 17 patients to alcohol was a slow decrease of potential, which contrasts with the normal alcohol rise. In patients with considerable residual peripheral field, alcohol produced a small increase of voltage, followed by a prolonged decrease. The slower decrease in the EOG voltage was evident in patients with small fields and could be seen even in those who had lost all visual function. Light caused small increments of EOG voltage (termed light rises), again related to the field size. CONCLUSIONS It is probable that the intracellular signaling system that causes the alcohol and light rises is lost in RP.