TIMING OF AMBLYOPIA THERAPY RELATIVE TO STRABISMUS SURGERY

Background. It is taught that amblyopia must be fully reversed before surgery for esotropia is undertaken to achieve the best surgical outco me. In some cases, this means delaying surgery for many months. The al ternative of operating early, before the completion of amblyopia thera py, and continuing to treat the amblyopia postoperatively has not been evaluated previously. Methods: Forty-seven children younger than 8 ye ars of age were identified with a history of both amblyopia and esotro pia. They had no other ocular, medical, or neurologic abnormalities. T hey had no prior strabismus surgery. Of these 47 patients, 26 had thei r amblyopia fully treated before surgery, and 21 underwent surgery bef ore completing amblyopia therapy. Five of the latter group did not req uire amblyopia therapy after surgery even though they were still ambly opic before operation. The motor outcome was assessed by comparing the motor alignment at 6 and 0.33 m using accommodative targets in primar y position before surgery, at 6 months after surgery, and at the child 's most recent visit. Motor success was defined in this study as a pos toperative deviation at distance fixation of 8 prism diopters or less. The sensory result was assessed by comparing the frequency of detecta ble stereoacuity. Results: The treatment groups did not differ signifi cantly in age, depth of amblyopia, refractive error, or preoperative a ngle. There was no significant difference detected in motor or sensory outcome whether amblyopia was fully or only partially treated before surgery. Conclusion: Performing corrective surgery in children with es otropia before full resolution of amblyopia is safe and efficient if t he amblyopia therapy is continued after surgery. This strategy permits earlier surgery without postponing the operation until full resolutio n of amblyopia. The finding that five patients did not require amblyop ia therapy after surgery suggests that eye re-alignment itself can hel p reverse amblyopia in some cases.