Extraocular muscle imbalance after scleral buckling

Postoperative muscle imbalance was prospectively evaluated in 44 patients who underwent conventional scleral buckling operations. Strabismus was present in 27 of 44 patients (61%). Heterotropia resolved spontaneously during the first six postoperative months in nine of 27 patients (33%). Diplopia persisted in six patients (13.6%) and limitation of ductions occurred in 22 of 44 patients (50%). The risk of developing postoperative strabismus was 2.5 times longer if an implant was placed under a rectus muscle. Otherwise, presence, degree, and direction of the duction deficits did not correlate with placement of a local implant under the corresponding rectus muscles or their antagonists. Reoperation, preoperative detachment of macula and size of the local implant were not statistically correlated with extraocular muscle imbalance. We believe that decrease in postoperative swelling and increase in visual acuity that allows phoria adaptation are the main causes of spontaneous resolution.