title: Hypertropia in unilateral isolated abducens palsy.
abstract: OBJECTIVE
  To evaluate the incidence and features of hypertropia in abducens nerve palsy.
  
  
  METHODS
  The records of consecutive patients with unilateral, isolated, previously unoperated abducens nerve palsy were reviewed for binocular alignment on cover testing, Krimsky measurement, or Hess screen testing. Patients with associated cranial nerve palsy (including bilateral abducens palsies), orbital disease, myasthenia gravis, Horner syndrome, hemiplegia, cerebellar signs, arteritis, or previous strabismus surgery were excluded. Control subjects underwent complete examination to confirm normality.
  
  
  RESULTS
  A total of 79 patients were included (40 males; mean age 49.2 years). Hypertropia in lateral or central gazes was present in 15 of 79 cases (19%) on alternate cover or Krimsky testing, in 32 of 56 cases (57%) on Hess screen testing, and absent in all 30 normal controls. Of cases with hypertropia, the mean of the greatest hypertropia in lateral or central gaze on was 5.0(Δ) ± 2.3(Δ) (standard deviation; range, 1(Δ)-8(Δ)) routine clinical examination, and 5.8(Δ) ± 4.2(Δ) (range, 2(Δ)-24(Δ)) on Hess screen testing. Of 39 cases with partial abducens palsy evaluated by Hess screen testing, the ipsilesional eye was hypertropic in 24 (61%) and hypotropic in 15 cases (39%).
  
  
  CONCLUSIONS
  Small-angle hypertropia is common in isolated, unilateral abducens and does not imply existence of multiple cranial neuropathies or skew deviation.
authors.affiliation: Department of Ophthalmology, SteinEye Institute, UCLA, Los Angeles, California.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Pihlblad
authors.affiliation: Department of Ophthalmology, SteinEye Institute, UCLA, Los Angeles, California; Department of Neurology, UCLA, Los Angeles; Neuroscience Interdepartmental Program, UCLA, Los Angeles; Bioengineering Interdepartmental Program, UCLA, Los Angeles. Electronic address: jld@jsei.ucla.edu.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Demer
mesh_terms: D020434:Abducens Nerve Diseases / Q000150:complications* / Q000175:diagnosis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005133:Eye Movements; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000473:pathology; D012189:Retrospective Studies; D013285:Strabismus / Q000175:diagnosis / Q000209:etiology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult