Corneal Topographic Changes after Horizontal Rectus Muscles Surgery

Paik, H J; Park, S O

Abstract

The refractive changes following extraocular muscles surgery are considered to be caused by corneal refractive changes which are caused by changes of tension on the globe after strabismus surgery. A prospective study was designed to evaluate the postoperative corneal refractive changes with horizontal strabismus surgery using computerized topography, manifest refraction and keratometry. The data were analyzed according to operating methods, surgical amounts and time after surgery. Measurement was performed on postoperative 1 day, 2 weeks, 1 month, and 2 months in 23 patients[35 eyes]. We evaluated 13 points of the corneal refractive index, the center of the corneal apex and apart from 1.5, 2.5, 3.5 mmin each axis corresponding to the 0degrees, 90degrees, 180degrees, 270degrees, respectively. In 12 patients[24 eyes] who were performed bilateral rectus recession and 11 patients[11 eyes] performed recession & resection and in bilateral rectus recession group at 1 day after surgery, significant corneal refractive changes occurred at 180degreesof recessed direction therefore we observed horizontal flattening of cornea, but it was not statistically significant to difference of 3 points of lateral rectus recessed direction. Induced corneal refractive changes were stabilized in 2 weeks after surgery and no significant changes occurred according to the operation methods and amounts. The changes of refractive power were detected 1 day after lateral rectus recession in the meridian of the recessed muscles[180degrees for lateral rectus] from center to periphery -0.77+/-0.54D, -0.78+/-0.56D, -0.85+/-0.59D respectively, but they were not statistically significant. Therefore, the results suggested that the postoperative corneal refractive changes mean corneal flattening in 180degrees meridian for lateral rectus muscle but they were not statistically significant according to operation methods and amounts. The changes of corneal refractive power were peaked at postoperative 1 day and gradually stabilized in 2 weeks after surgery.