title: Cyclic esotropia with development of a high accommodative convergence to accommodation ratio after surgery for intermittent exotropia.
abstract: OBJECTIVE
  To report a patient with cyclic esotropia with a high accommodative convergence to accommodation (AC/A) ratio after surgical correction of intermittent exotropia who was found to have bilateral anomalous medial rectus muscle insertion sites.
  
  
  METHODS
  A 5-year-old girl developed intermittent esotropia on alternating days after undergoing bilateral lateral rectus recessions for correction of intermittent exotropia. Alternate prism and cover measurement of ocular alignment and binocular function was assessed on consecutive days. Surgical correction was performed for the full amount measured on a "crossed" day.
  
  
  RESULTS
  On "straight" days, her eyes were orthotropic with normal binocular vision. Examination on "crossed" days revealed a left esotropia of 75 prism diopters (PD) at near fixation and 40 PD at distance fixation in primary gaze without fusion or stereopsis. The patient underwent bilateral medial rectus recessions in conjunction with posterior fixation sutures (MRP). During surgery, the distance from the limbus to the medial rectus muscle insertion was 3.5 mm bilaterally. Postoperatively, the cycle was broken, and the esotropia disappeared with no recurrence at the latest follow-up at 12 months.
  
  
  CONCLUSIONS
  MRP is an effective procedure for correction of cyclic esotropia with a high AC/A ratio. Strabismus surgeons should design surgical strategies based on preoperative measurement of deviations at all distances and the anatomy of muscle insertions in patients with cyclic esotropia.
authors.affiliation: Department of Ophthalmology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, 610041, Sichuan, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, 610041, Sichuan, People's Republic of China.
authors.forename: Bingjie
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, 610041, Sichuan, People's Republic of China. b.q15651@hotmail.com.
authors.forename: Longqian
authors.initials: L
authors.lastname: Liu
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D002675:Child, Preschool; D004948:Esotropia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005099:Exotropia / Q000601:surgery*; D005260:Female; D006801:Humans; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications; D015348:Vision, Binocular / Q000502:physiology*
keywords: Cyclic esotropia; Cyclic strabismus; Extraocular muscle surgery