Long-term astigmatism changes following horizontal muscle recession: a prospective cohort study

Corneal tomography changes following major (6 mm) medial rectus muscle recession: a prospective cohort study using Pentacam®

INTRODUCTION

The aim of this study is to evaluate changes in corneal astigmatism, axial anterior corneal curvature, as well as changes in the anterior chamber depth and central corneal thickness, 2 months following the unilateral recession of medial rectus muscle in children.

METHODS

Thirty-three children with esotropia were prospectively evaluated following unilateral medial rectus muscle recession, using Pentacam®. Comparisons were made between the operated and fellow unoperated eyes, pre, and postoperatively. The assessment was made for changes in the radius of axial curvature on major meridians at 3 and 3.5 mm from the optical corneal center in the mid-peripheral zone. Astigmatism changes of the anterior and posterior corneal surface were calculated using vector analysis software (astigMATIC®). ANOVA model was used to examine the interaction between age or central corneal thickness and postoperative changes in anterior and posterior surface corneal astigmatism.

RESULTS

In the intervention group, changes in anterior and posterior corneal surface astigmatism were statistically significant, with a mean increase of 0.59Dx92 and 0.08Dx91, respectively. In the mid-peripheral corneal zone, there is an increase in the radius of anterior corneal axial curvature more evident nasally 3.5 mm from the corneal center on the horizontal meridian, with corresponding decrease superiorly and inferiorly at 3 and 3.5 mm from the corneal center on the vertical meridian.

DISCUSSION

The changes in total astigmatism of the operated eyes are mainly attributed to the anterior corneal surface. These changes are associated with flattening in the 180 meridian of the cornea, leading to a shift to "with-the-rule" astigmatism.

Evaluation of Macular Thickness Changes Following Large Horizontal Rectus Muscle Recession: A Prospective Cohort Study

Aim The aim of the study was to evaluate the long-term effect of large horizontal rectus muscle recession on macula thickness using spectral domain optical coherence tomography (SD-OCT). Material and methods Forty-two children were included in the study. The intervention groups were the medial rectus (MR) group (=20 eyes ) and the lateral rectus (LR) group (=22 eyes), including the eyes that underwent large medial and lateral rectus muscle recession, respectively. The control group included the fellow 42 unoperated eyes of the same children. Each eye was scanned using Topcon Maestro2 OCT-Angiography (OCTA; Topcon, Tokyo, Japan) preoperatively and then two months following surgery. A paired t-test was used to compare the mean difference in macular thickness between the intervention and control groups using the statistical program R (R Foundation for Statistical Computing, Vienna, Austria). Results The mean change in central, parafoveal, and perifoveal macular thickness of the intervention group was not statistically significant. Conclusion The long-term changes in macular thickness, as evaluated using SD-OCT both for the central and peripheral regions of the fovea, following large horizontal rectus muscle recession surgery, are not statistically significant.