Controlled study comparing CAM treatment with occlusion therapy.

The treatment of amblyopia is centuries old. A systematic description of occlusion therapy was provided by Leclerc' in 1743, and to this day the method has by and large remained unchanged. Although occlusion often leads to beneficial results,23 there are cases where it is unacceptable to the child and frustrating for the parents. When occlusion has failed other methods have been tried." Dazzling or after-image stimulation of the foveola requires active co-operation from the child and therefore is often applied in a very late stage of the visually immature period. The success rate is poor. Penalisation,8 another alternative, works best in cases of amblyopia combined with hyperopia and/or nystagmus. In one of their earlier papers Hubel and Wiesel9 showed that there are cell clusters in the visual cortex that only respond to rectangular stimuli with a specific orientation. Thus different clusters respond to different angles of orientation. This forms the basis of the latest addition to the amblyopia therapy arsenal -the CAM stimulator. In 1978 when Banks et al.'° " described the method and the instrument, reporting improvement in 38 of 40 cases, the method seemed very promising. This led us to initiate this study in which CAM treatment was compared with occlusion on equally large randomly allocated groups. Since then others'2 13 have reported that CAM is not only as efficient as occlusion but also produces results sooner and therefore should be the treatment of choice.