Background Strabismus is a common disorder that is mostly treated surgically. Extraocular muscle surgery may induce refractive and corneal topographic changes. Aim To study the effect of horizontal strabismus surgery on corneal topography Patients and methods This prospective interventional randomized study was carried out on 20 patients aged from 5 to 30 years old diagnosed with horizontal strabismus who did not undergo any ocular surgery before. They were divided into four groups. We did lateral rectus recession in the first group, lateral rectus resection in the second group, medial rectus resection in the third group, and medial rectus recession in the fourth one. We compared the spherical equivalent and the corneal topographic parameters (K1, K2, the power and the axis of the astigmatism) preoperative, at 1 month postoperative, and at 6 month postoperative. Results There was myopic shift in the spherical equivalent in all groups and it was more significant after recession surgery. There was a statistically significant change in K1, K2, and astigmatism power after recession of medial and lateral recti muscles which persisted till the postoperative sixth month. The change after resection of medial and lateral recti muscles was insignificant. The change in the axis was insignificant in all groups. Conclusions Recession surgery of medial or lateral recti has more effect on refraction and corneal topography than resection. Horizontal strabismus surgeries induce a significant myopic shift in the spherical equivalent and do not induce a significant change in the axis.
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