title: Effects of inferior oblique muscle-weakening surgery on the Bielschowsky head-tilt phenomenon in patients with superior oblique palsy habitually fixating with the paretic eye.
abstract: OBJECTIVE
  To evaluate the usefulness of inferior oblique (IO) weakening surgery on a paretic eye for correcting vertical deviation in three positions of gaze by comparing the surgical results in 2 types of unilateral superior oblique (SO) palsy.
  
  
  METHODS
  The patients were divided into 2 groups: 27 patients fixated with the paretic eye and 61 patients fixated with the non-paretic eye (control). The former had hypotropia and the latter hypertropia. All patients underwent IO recession of the paretic eye. We compared the corrective effects, percentage changes in the decrease of vertical deviation of the primary position (PP), vertical deviation on ipsilateral head tilt, i.e., the Bielschowsky head-tilt phenomenon (BHP), and differences in vertical deviation between ipsilateral and contralateral head tilt (BHTD) relative to the preoperative values between the 2 groups.
  
  
  RESULTS
  Mean percentage decrease in vertical deviation of the BHP and BHTD in the control group was larger at 3, 6, and 12 months, but no significant difference was observed between the 2 groups except for the BHP at 12 months (52% for case vs. 70% for control, p = 0.04).
  
  
  CONCLUSIONS
  IO weakening in the paretic eye was effective irrespective of the preferred eye for fixation on PP and head-tilt position.
authors.affiliation: Department of Ophthalmology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, Okayama-ken, 700-8558, Japan. fumiko-k@mvf.biglobe.ne.jp.|Department of Ophthalmology, Ibara Municipal Hospital, 1186 Ibara-cho, Ibara, Okayama-ken, 715-0019, Japan. fumiko-k@mvf.biglobe.ne.jp.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kishimoto
authors.affiliation: Department of Ophthalmology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, Okayama-ken, 700-8558, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hasebe
authors.affiliation: Department of Ophthalmology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, Okayama-ken, 700-8558, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtsuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009123:Muscle Hypotonia / Q000503:physiopathology*; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D011187:Posture / Q000502:physiology*; D012189:Retrospective Studies; D013285:Strabismus / Q000503:physiopathology / Q000601:surgery*; D020432:Trochlear Nerve Diseases / Q000503:physiopathology / Q000601:surgery*; D015348:Vision, Binocular / Q000502:physiology; D055815:Young Adult