Combined recession and resection surgery in the management of convergence excess esotropia with different levels of AC/A ratio

Abstract

To study prospectively the effect of extirpating the proprioceptive impulse at the myotendinous junction combined with recession of the medial rectus muscles in patients with convergence excess esotropia. A total of 21 patients with different sizes of AC/A ratios (high, 8; normal, 12; low, 1)underwent a surgical procedure consisting of combining resection of 2.5mm of the insertional end of the medial rectus muscles with recession from the original insertion, based on the patient's angle of esotropia at 1/3m while wearing full cycloplegic refraction, with an additional recession of 1mm for each rectus muscle based on current surgical tables. A satisfactory outcome was defined as orthotropia or esotropia of <10Δ at near and distance fixations with available correction and reduction of the distance--near disparity to <10Δ. All patients, regardless of the size of AC/A ratio and the amount of near-distance disparity, had satisfactory alignments at near and distance fixations, with residual near-distance disparity of <10Δ. Consecutive distance exotropia did not develop even when there was preoperative distance orthotropia. Outcome measures remained stable for a mean of 4.3years. None of the 8 patients with high AC/A ratios required bifocal wear or overcorrection prescriptions to maintain alignment postoperatively. This technique of combined resection and recession of the medial rectus muscle shows promise in the treatment of convergence excess esotropia. The main advantage is improvement in distance alignment while selectively reducing the near angle in patients with different levels of AC/A ratios.