Surgical impact on corneal curvature and astigmatism in pediatric exotropia patients

Unilateral recession of the lateral rectus muscle in children with intermittent exotropia leads to significant changes in corneal astigmatism, according to a study. Specifically, the surgery results in increased astigmatism primarily due to alterations in the anterior corneal surface, causing a shift towards “with-the-rule” astigmatism.

The study, which included 37 children suffering from intermittent exotropia, measured changes in corneal astigmatism, axial anterior corneal curvature, anterior chamber depth, and central corneal thickness (CCT) 2 months post-surgery. Using Pentacam for detailed corneal analysis, researchers compared the operated eye with the unoperated fellow eye.

There were statistically significant changes in both anterior and posterior corneal surface astigmatism, with the anterior surface showing a mean increase of 0.56 Diopters (Dx) at 90 degrees and the posterior surface a 0.08 Dx increase at 87 degrees. There was a significant increase in the radius of anterior corneal axial curvature in the mid-peripheral zone, predominantly on the horizontal meridian, while a decrease was observed on the vertical meridian.

Reference
Paraskevopoulos K, Karakosta C, Feretzakis G, et al. Corneal changes after large (9mm) lateral rectus muscle recession measured with Pentacam. Strabismus. 2024;doi: 10.1080/09273972.2024.2402455. Epub ahead of print. PMID: 39297197.