A Randomized Trial of Bilateral Lateral Rectus Recession versus Unilateral Lateral Rectus Recession with Medial Rectus Resection for Intermittent Exotropia

Sponsor: Jaeb Center for Health ResearchPrincipal Investigator: Yasmin Bradfield, MDStudy Coordinator: Angie Adler

Study objective:

To evaluate the effectiveness of bilateral lateral rectus muscle recession versus unilateral lateral rectus recession with medial rectus resection procedures for the treatment of basic type and pseudo divergence excess type intermittent exotropia.

Study design:

Participation involves an eye exam once a year for 5 years.

Inclusion criteria:

  • Age 3 to < 11 years
  • Intermittent exotropia (manifest deviation)
  • Stereoacuity of 400 arcsec or better at near by Preschool Randot stereotest (better of 2 measures)
  • Visual acuity in the worse eye at least 0.3 logMAR (20/40 on ATS HOTV or 70 letters on E-ETDRS)
  • No interocular difference of visual acuity more than 0.2 logMAR (2 lines on ATS HOTV or 10 letters on E-ETDRS testing)
  • Absence of high AC/A ratio (exclude > 6:1)
  • No previous intraocular surgery, strabismus surgery, or botulinum toxin treatment
  • Investigator planning to perform surgery for correction of IXT
  • No hyperopia greater than +3.50 D spherical equivalent (SE) in either eye

Exclusion criteria:

  • Coexisting vertical deviation, oblique muscle dysfunction, dissociated vertical deviation (DVD), or A or V pattern, any of which the investigator plans to address with vertical transposition of horizontal rectus muscles, oblique surgery, or vertical rectus muscle surgery, i.e., only small vertical deviations, oblique muscle dysfunction, DVD, and A or V patterns not requiring surgery are allowed
  • Limitation of ocular rotations due to restrictive or paretic strabismus
  • Craniofacial malformations affecting the orbits
  • Interocular visual acuity difference of more than 0.2 logMAR (2 lines on ATS HOTV for patients 3 to < 7 years old or 10 letters on E-ETDRS for patients ≥ 7 years old) and/or investigator plans to initiate amblyopia treatment at this time
  • High AC/A ratio (exclude > 6:1 by gradient method)
  • Prior strabismus surgery or botulinum toxin injection
  • Prior intraocular or refractive surgery

Contact Angie Adler with questions: 608-265-7557.

For more information about this study:


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