[Early and late occurring consecutive exotropia following a medial rectus faden operation].

UNLABELLED

The main advantage of the bilateral medial rectus faden operation (posterior fixation suture) for the treatment of essential infantile esotropia is the low occurrence of delayed consecutive exotropia. Nevertheless, this unwanted complication also occasionally occurs after a faden operation.

PATIENTS

All patients operated on between 1988 and 1997 for subsequent exotropia following bimedial faden operations without recessions were included in this study. Surgery for exotropia consisted of uni- or bilateral lateral rectus muscle recession or in removing the faden with or without resection.

RESULTS

Within the 10 years examined a bimedial faden operation (without recession) was performed in 1569 patients. In the same period 49 patients were operated on for a consecutive exotropia after a faden operation. Thirty-four (69.4%) of the consecutive exotrope patients showed exodeviation immediately following the surgery (group I). Fifteen (30.6%) patients developed manifest exotropia 1-53 months later (group II). The hyperopia at the time of the first operation was 2.5 D in group I and 2.3 D in group II (spherical equivalent). A bimedial faden operation with simultaneous shortening of the anterior muscle segment was performed in four patients in group II and only in two patients in group I. Cerebral palsy was evident in three patients in group II and also so in three patients in group I.

CONCLUSION

Exotropia appearing immediately after surgery is most likely the result of an individually overdosed operation. This conclusion is not sufficient for delayed exotropia. Motor and sensory instabilities, such as those in patients needing a faden operation with simultaneous shortening of the anterior muscle segment for the treatment of convergence excess with no deviation at far or in patients showing cerebral palsy, seem to increase the risk of delayed consecutive exotropia. The mean interval between the initial surgery and the manifestation of consecutive exotropia is lower than is known from other surgical procedures.