Early and delayed consecutive exotropia following a medial rectus faden operation

The main advantage of the bilateral medial rectus faden operation (posterio r fixation suture) for the treatment of essential infantile esotropia is th e low occurrence of delayed consecutive exotropia. Nevertheless, this unwan ted complication also occasionally occurs after a faden operation. Patients: All patients operated on between 1988 and 1997 for subsequent exo tropia following bimedial faden operations without recessions were included in this study. Surgery for exotropia consisted of uni- or bilateral latera l rectus muscle recession or in removing the faden with or without resectio n. Results: Within the 10 years examined a bimedial faden operation (without r ecession) was performed in 1569 patients. In the same period 49 patients we re operated on for a consecutive exotropia after a faden operation. Thirty- four (69.4 %) of the consecutive exotrope patients showed exodeviation imme diately following the surgery (group I). Fifteen (30.6 %) patients develope d manifest exotropia 1-53 months later (group II). The hyperopia at the tim e of the first operation was 2.5 D in group I and 2.3 D in group II (spheri cal 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 patie nts in group II and also so in three patients in group I. Conclusion: Exotropia appearing immediately after surgery is most likely th e result of an individually overdosed operation. This conclusion is not suf ficient for delayed exotropia. Motor and sensory instabilities, such as tho se in patients needing a faden operation with simultaneous shortening of th e anterior muscle segment for the treatment of convergence excess with no d eviation at far or in patients showing cerebral palsy, seem to increase the risk of delayed consecutive exotropia. The mean interval between the initi al surgery and the manifestation of consecutive exotropia is lower than is known from other surgical procedures.