title: Two horizontal rectus eye muscle surgery combined with botulinum toxin for the treatment of very large angle esotropia. A pilot study.
abstract: OBJECTIVE
  To evaluate the effectiveness of a proposed new protocol for the primary treatment for very large angle esotropia: two muscle horizontal rectus muscle surgery with simultaneous botulinum toxin A injection in a small pilot study.
  
  
  METHODS
  Eight patients who had esotropia at near (ET') greater than 60 prism diopters (in actuality 70 to 100 prism diopters ET') underwent 2 muscle horizontal rectus surgery with simultaneous botulinum toxin A injection of the medial rectus intraoperatively. This was the only surgical procedure for all patients included in this report. Seven patients underwent bilateral medial rectus recession and bilateral injection, and one patient underwent a unilateral medial rectus recession / lateral rectus resection procedure with unilateral medial rectus injection.
  
  
  RESULTS
  Postoperatively, 6 of the 8 patients demonstrated residual esotropia at near of less than 10 prism diopters and were considered "successful" by the conventional criteria of binocular alignment within 8 prism diopters of orthotropia. Two undercorrections occurred in patients with 100 and 85 prism diopters of preop ET' respectively. But 3 other patients with such large deviations had satisfactory results. All patients and families were satisfied with postoperative binocular alignment, so no further surgery was undertaken. The patient who underwent unilateral surgery had the least surgical effect and was the largest undercorrection, probably because only one medial rectus received a Botox injection. Considering only the bilateral cases, results were "successful" in 6 of 7 cases. Most patients suffered an extended period of Botox induced exotropia in the postop' period before recovery from the paresis. One patient had a transient, successfully treated, postoperative strabismic amblyopia while exotropic.
  
  
  CONCLUSIONS
  Bilateral medial rectus recession with simultaneous botulinum injection is a safe and effective primary surgical procedure for very large angle esotropia. A more extensive study is indicated to confirm these findings.
authors.affiliation: Pediatric Ophthalmology Division, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia. arif.khan@mssm.edu
authors.forename: Arif O
authors.initials: AO
authors.lastname: Khan
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D004948:Esotropia / Q000188:drug therapy* / Q000601:surgery*; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D010865:Pilot Projects; D012189:Retrospective Studies; D015348:Vision, Binocular
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A