title: Surgical Management of Unilateral Superior Oblique Palsy: Thirty Years of Experience.
abstract: OBJECTIVE
  We describe the clinical characteristics of 252 patients with unilateral superior oblique palsy who underwent strabismus surgery. We assess if a predetermined surgical strategy, based on preoperative alignment and motility measurements, was effective in treating these patients. On this basis, the patients were divided into three different treatment groups.
  
  
  METHODS
  Two-hundred fifty-two patients were identified retrospectively and classified into three groups according to the performed procedures: 1) inferior oblique weakening; 2) inferior rectus recession; 3) combined inferior oblique weakening and inferior rectus recession. Demographic and clinical data were recorded. Criteria for surgical success included good postoperative alignment (distance, primary position alignment ≤5Δ), and improvement of diplopia and of abnormal head posture. Subgroup analyses of surgical outcome were performed for small (<12Δ) versus large (>20Δ) preoperative hypertropia in the group that underwent inferior oblique weakening, and for inferior oblique disinsertion-myectomy versus inferior oblique recession.
  
  
  RESULTS
  Mean forced primary position (PP) hypertropia decreased from 14.3Δ(range 3-37Δ) to 4.5Δ(range 0-30Δ) in Group 1, from 13Δ(range 1-30Δ) to 2Δ(range -20-20Δ) in Group 2, and from 25.7Δ(range 6-40Δ) to 1.3Δ(range -12-18Δ) in Group 3. Group 1 had the lowest re-operation rate (7.6%), followed by Group 2 (16%) and Group 3 (25.9%). Final surgical success rates were similar in three groups. Inferior oblique weakening was more predictable for small primary position hypertropia, but still yielded 85% success rate in large deviations. Inferior oblique disinsertion-myectomy resulted in more favorable results than inferior oblique recession (P < 0.05).
  
  
  CONCLUSIONS
  When a predetermined surgical strategy is applied to individual patients with unilateral superior oblique palsy, excellent functional improvement can be achieved in the majority of patients.
authors: From the Department of Ophthalmology, University of Montreal, Montreal, Quebec.
authors: Qianqian
authors: Q
authors: Wang
authors: From the Department of Ophthalmology, University of Montreal, Montreal, Quebec; michael.flanders@mcgill.ca.|Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors: Michael
authors: M
authors: Flanders
mesh_terms: D006801:Humans; D009801:Oculomotor Muscles / Q000601:surgery*; D012189:Retrospective Studies; D013285:Strabismus / Q000601:surgery*; D020432:Trochlear Nerve Diseases / Q000601:surgery*
keywords: fourth cranial nerve palsy; inferior oblique disinsertion-myectomy; inferior oblique recession; inferior rectus recession; superior oblique palsy; unilateral