Macular Thickness Following Strabismus Surgery as Determined by Optical Coherence Tomography

Abstract

Purpose: To investigate macular changes following strabismus surgery by using optical coherence tomography (OCT).

Methods: The authors prospectively evaluated 60 eyes of 30 patients undergoing unilateral extraocular muscle surgery. OCT measurements employing the fast macular thickness mapping protocol were performed 1 day prior to surgery and 1 day postoperatively. Postoperative macular changes in the study eye that was operated on (n = 30) were compared with the fellow control eye (n = 30, controls).

Results: There was an increase in mean ± standard deviation central foveal thickness (CFT) in the operated eyes, from 201.63 ± 18.36 µm at baseline to 206.03 ± 22.73 µm postoperatively (P = .024). Preoperative and postoperative perifoveal outer temporal quadrant thicknesses were 220.10 ± 16.23 and 225.80 ± 14.78 µm, respectively (P = .009). There were no differences between preoperative and postoperative retinal thickness measurements for all measured areas in the control eyes. Eyes that underwent surgery involving the rectus muscles showed a trend toward a greater CFT increase compared with eyes that had oblique muscle surgery (P = .070).

Conclusions: The authors found subclinical increases in the foveal and perifoveal macular thicknesses following extraocular muscle surgery. These findings could be attributed to change in the mechanical forces caused by the new position of the extraocular muscles and transmitted via the sclera or, alternatively, to postoperative inflammation and alterations in the blood-retinal barrier. The clinical implications of these findings remain to be clarified.