EFFECT OF ONGOING TREATMENT OF AMBLYOPIA ON SURGICAL OUTCOME IN ESOTROPIA

Purpose: Classic teaching recommends completion of amblyopia therapy p rior to surgical correction of esotropia. Recent reports, however, sug gest that incomplete treatment does not adversely affect surgical outc ome. This study assesses the effect of incompletely treated amblyopia on the success rate of bimedial rectus recession in infantile and acqu ired esotropia. Methods: All patients (n=102) with esotropia undergoin g bimedial rectus recession in 1994 who met inclusion criteria were re viewed. Subjects were classified as having infantile; acquired, partia lly accommodative; or acquired, nonaccommodative esotropia for compari son. Amblyopia was classified as none, mild, moderate, or severe. Surg ical success was defined as orthophoria +/- 8 prism diopters and was a ssessed at the second postoperative visit (4 to 6 weeks after surgery) . Other variables studied included mean surgical age, preoperative dev iation, millimeters of surgery, and amount of follow up. Results: For all patients, surgical success rates were as follows: no amblyopia, 84 .3% (43/51); mild amblyopia, 81.6% (31/38); and moderate amblyopia, 61 .5% (8/13). All patients with severe amblyopia underwent unilateral re cess/resect procedures and were excluded. Of the esotropia subgroups, a statistically significant decrease in surgical success was noted onl y in the infantile esotropia group with moderate amblyopia. For this g roup, success rates were as follows: no amblyopia, 77.1% (27/35); mild amblyopia, 81.0% (17/21); and moderate amblyopia, 16.7% (1/6), P=0.00 5. Conclusions: Performing corrective surgery on patients with infanti le esotropia leads to poorer surgical outcome if moderate amblyopia is present at the time of surgery. Mild amblyopia, however, does not adv ersely affect surgical outcome in patients with infantile esotropia. F urthermore, the presence of mild or moderate amblyopia does not appear to have an influence on surgical outcome for patients with acquired e sotropia. The effect of amblyopia on sensory outcome was not studied a s most patients were too young for reliable sensory testing.