[Induced Incomitance of one Muscle Strabismus Surgery in Comparison to Unilateral Recess-Resect Procedures]

Klin Monbl Augenheilkd. 2015 Oct;232(10):1174-7. doi: 10.1055/s-0041-104776. Epub 2015 Oct 29.
[Article in German]


Background: Surgical correction of intermediate squint angles may be performed on one muscle alone or as a combined unilateral recess-resect procedure. No larger case series has yet systematically measured the amount of induced incomitance that could potentially lead to visual disturbances.

Methods: 31 patients with strabismus and binocular vision (phoria or intermittent strabismus) were operated on one extraocular eye muscle; 30 patients underwent a unilateral recess-resect procedure. Preoperatively and three months postoperatively, we measured the latent angle of squint on a tangent screen over the horizontal 60° in 10° increments and then calculated the amount of induced incomitance.

Results: After one muscle surgery, the induced incomitance was 1.7° over a 20° gaze range, 3.2° over a 40° gaze range and 3.8° over a 60° gaze range. For recess-resect procedures, the induced incomitance was 1.4°, 2.6° and 3.4°, respectively. A significant correlation between the surgical dose and the induced incomitance was only seen in one muscle surgery for the 40° and 60° gaze range, but not for the 20° gaze range. A subgroup analysis of patients with an identical surgical dose in one and two muscle procedures (6-8 mm) found greater induced incomitance in one muscle procedures, but only for the 40° and 60° gaze range (p = 0.02). Double vision in any gaze direction was reported by 16 % of patients after one muscle surgery and 10 % of patients after unilateral recess-resect surgery (p > 0.05).

Conclusion: One muscle surgery is a viable option in small and intermediate angles of squint. The induced incomitance is rather small and does not lead to significant visual disturbances in the central gaze range.

Publication types

  • Comparative Study
  • Controlled Clinical Trial
  • English Abstract

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Female
  • Humans
  • Male
  • Middle Aged
  • Oculomotor Muscles / surgery*
  • Ophthalmologic Surgical Procedures / methods*
  • Reconstructive Surgical Procedures / methods*
  • Strabismus / diagnosis*
  • Strabismus / surgery*
  • Treatment Outcome
  • Visual Acuity*
  • Young Adult