[Postoperative secondary divergent strabismus. Statistical analysis of 160 consecutive exotropias]

Exotropias secondary to convergent squint surgery are fully different from primary exotropias. Their frequency appears to be largely variable according to the operative procedures. The computerized analysis of 160 consecutive exotropias reveals the compound nature of their motor impairments. In each case it is necessary to carry out a careful check up of various causal parameters, but the authors find they are not bound by simple correlations. In all cases an elongation reducing one or several muscles is noticed. Such anomalies are much more frequent and heavy than those observed in primary esotropias. Their iatrogenic origin is unquestionable. In 37% of the cases heavy capsular scars have been observed; their consequences on passive forces are obvious, but it is difficult to carry out their exact evaluation by the usual clinical tests. In that series the resulting surgical planning was made according to the various abnormal parameters had allowed the achievement of a good motor result in 89% of the cases. In 86% of the cases, only one additional operative procedure was necessary.