Characteristics of exodeviations: I. A comparison of three classes.

A retrospective study of 179 patients (69 males and 110 females) with binocular visual dysfunction and an exodeviation at distance or near or at both distances has been completed. The mean age of 19.7 years was significantly younger than the population from which they were referred. The patients were classed as convergence insufficiency, equal exodeviation, or divergence excess, based on the relation of the distance and near angles of deviation. Based on these criteria, interaction was found to be present between the diagnostic class and the frequency of the deviation, the symptoms reported, and a variety of clinical parameters such as the angles of deviation at distance and near, the AC/A ratio, positive and negative vergence values, the amplitude of accommodation, and the threshold of stereopsis. A number of statistical relations were noted between the frequency of the deviation vs. the symptoms reported and a variety of the clinical parameters. The implications of these results are discussed.