Corneal Astigmatic and Refractive Changes after Rectus Muscle Surgery

Objective:In the present study, we investigated the postoperative astigmatic and refractive changes in patients with rectus muscle strabismus surgery. Materials and methods:Ninety-three eyes of 51 patients who underwent strabismus surgery at Amir- Almomenin Hospital, Rasht, Iran, were enrolled. The ocular measurements before surgery as well as one month, three and six months postoperatively included cycloplegic refraction, the degree of near and far deviation, mean corneal power, mean keratometry, spherical equivalent (SE) and the change of astigmatism cylinder (measured using power vector analysis). All data were analyzed using SPSS software, version 21. Results:The mean age of participants was 18.31±14.58 years. A similar myopic shift was observed in all deviation groups. The mean SE values differed according to the type of surgery one month and three months postoperatively, with maximum change being seen in medial rectus (MR) recess + inferior oblique (IO) myectomy and in MR recess and lateral rectus (LR) recess six months after surgery. The change in mean J0 remained significant six months postoperatively only in MR recess surgery and in medial and lateral rectus recess groups based on topography (both P<0.001). The postoperative J0 and J45 differed according to the type of surgery (PP<0.001 and 0.007, respectively). The mean keratometry was different before-after LR recess (the minimum change), MR recess and MR recess + IO myectomy groups (the maximum change; PP<0.05). Conclusion:Refractive error toward myopic shift and with-the-rule (WTR) astigmatism are common after strabismus surgery on the rectus muscles, most of which sustain until six months postoperatively.