Background: Consecutive exotropia (or secondary exotropia) is a complication that can arise at any stage in the management of esotropia, be it medical or surgical. It is notoriously difficult to treat due to its tendency to relapse, making extensive surgery necessary in some cases. Case series: We present a series of 7 cases all operated by the same surgical team for convergent strabismus, that were later, at varying intervals, reoperated for consecutive exotropia. All cases were followed-up for a minimum of 4 years after the second surgery. Repeat surgery for residual consecutive exotropia was not needed in any case.
Results: Although most patients had risk factors impeding normal binocular vision (amblyopia, a long history of abnormal binocular function, vertical deviations), the final result from a functional standpoint, in most cases, was at least simultaneous perception at near fixation. Anatomically, all cases were within 10 XT and 10 ET for the remainder of the follow-up, which was aesthetically acceptable.
Conclusions: Consecutive exotropia may take years to develop and is usually associated with amblyopia and low binocular vision potential. Large initial medial rectus recessions (greater than 5 mm) should be avoided as they can limit the muscle’s function.
Amblyopia should be, at least partially, corrected prior to surgery and continued afterwards if necessary. Near binocular vision is more common in strabismus patients than distance binocular vision (1) and some authors argue that it is actually more useful in every day activities (2).
Abbreviations: BCVA – best corrected visual acuity, OD – oculus dexter, OS – oculus sinister, OU – oculus uterque, ET – esotropia, XT – exotropia, PD – prism diopterFull text sources