Horizontal rectus muscle surgeries may cause changes in corneal and anterior segment parameters. Corneal topography is an important device for identifying these alterations.
The aim of this work is to evaluate the effects of horizontal rectus muscle surgeries on corneal topography, anterior chamber parameters and corneal wavefront aberrations.
Patients who had horizontal rectus muscle surgery from a single hospital in Turkey between September 2021 and March 2022 were invited to participate. Anterior segment parameters and corneal wavefront aberrations were analysed using a Pentacam device. Axial lengths were measured with an intraocular lens biometric instrument. Tests were performed prior to surgery and 3 months after surgery and results were compared. Parameters with significant change were determined in the whole study group, single muscle and two-muscle groups. The amount of change (Δ) in all parameters was compared between the groups that underwent single muscle and two-muscle surgeries.
For this prospective study, 44 eyes of 35 patients were included. The mean age was 18.10 ± 6.93 (7-28) (mean ± standard deviation (range)) years. Of the eyes, 22 (50%) underwent single muscle recession surgery. Two-muscle surgeries (recession and resection combination) were performed in 22 eyes. In the whole study group, axial length, anterior corneal surface-steep keratometry, anterior corneal astigmatism and anterior chamber volume increased significantly in the postoperative period ( = 0.002,  < 0.001,  < 0.001, and  = 0.007 respectively). Anterior corneal surface-flat keratometry decreased significantly ( = 0.002). While root mean square (RMS)-Spherical aberration increased significantly for the total corneal surface ( < 0.001), RMS-Trefoil 0° decreased ( = 0.039). Only ΔSteep keratometry and ΔMean keratometry parameters were changed significantly between the two groups.
Horizontal muscle surgeries may cause changes in corneal topography, anterior chamber parameters and corneal aberrations. The number of muscles operated during the surgery does not seem to greatly affect the magnitude of changes that occur.