For the correction of large-angle infantile esotropia and decompensated microtropia three horizontal muscle surgery is associated with a high success rate. Only a very low rate of consecutive exotropia does occur.

Vision screening by the school medical services enrols most of the children from a single age group. The Snellen E charts used for the monocular distance acuity, together with the TNO stereo test, appear to constitute an effective testing combination. Ophthalmological follow-up examinations of the affected children revealed that one third were afflicted by amblyogenic factors.