Sensorial anomalies in strabismus. (suppression, anomalous correspondence, amblyopia).

Some concepts regarding suppression, anomalous correspondence and amblyopia are revised according to the sensorial findings obtainable from esotropic patients directly in casual seeing (with the aid of the striated glasses test) and by grading a sensorial dissociating effect (with the aid of a bar of optical filters). The following points are emphasized: 1. Suppression appears to be minimal in small angle strabismus where diplopia seems mainly to be avoided by an anomalous correspondence mechanism. On the contrary, suppression is the prevalent mechanism in large angle strabismus. 2. The anomalous correspondence mechanism may lead to a weak type of anomalous binocular vision which is easily interrupted by light optical filters or by dissociating tests. 3. The subjective space of patients with anomalous binocular vision resembles that of normal binocular vision in some aspects. 4. The development of amblyopia is interpreted in the light of these new concepts on suppression and anomalous binocular vision. 5. Postoperatively, anomalous correspondence rapidly re-adapts to the smaller angle deviation and may normalize if the deviation is completely eliminated. This is evident only in casual seeing; for a certain time, dissociating tests reveal the preoperative correspondence status. This behaviour of correspondence in casual seeing has led to attempts at normalizing anomalous correspondence by prism therapy. Newly observed sensotio-motorial obstacles, however, have been found to frequently hamper treatment in casual seeing.