Evaluation of extraocular muscles with magnetic resonance imaging before and after strabismus surgery

In our study, the data of 31 patients aged 5 years and older with horizontal strabismus who had an operation between February 2019 and March 2022 in Gaziantep University Faculty of Medicine Hospital, Department of Ophthalmology were compiled. In the study, demographic data of the patients, strabismus information for which surgical indication was given, preoperative examinations, preoperative surgery planned and data obtained by magnetic resonance imaging (MRI) were recorded. In our study, we aimed to evaluate the extraocular muscles and to examine the changes in the extraocular muscles before and after the operation with the help of orbital MRI and LifeX software program. The mean age of the patients included in the study was 17,3 years and the male sex ratio was %53,3. 12 (%38.7) patients had esotropia and 19 (%61.3) patients had exotropia. Bilateral regression was performed in 23 patients, resection with regression in 5 patients, and bilateral resection in 3 patients. When regression and resection surgeries are compared; resection surgery was applied to the older age group compared to regression surgery (p=0.043). In the 3rd month postoperative follow-up, it was determined that the surgical success of the resectioned eyes was higher than the regression eyes. It was observed that as the amount of deviation before the operation increased in the regressed eyes, the amount of residual deviation after the operation increased (r=0.748, p=0.001). When the compliance with the surgical plan is considered; In the regressed muscles, a compliance rate of %90 was found within ±1 mm acceptable margin of error. In intraoperative comparison of the distances of the insertions of the muscles to the limbus and the measurements with the LifeX software; With MRI, it was observed that LifeX software performed a %94 successful measurement within ±1 mm margin of error. When muscle volume is evaluated; the mean preoperative measurments of muscle volume (PMOMV) of the inner recti was found to be higher than that of the outer rectus, but there was no statistically significant difference (p>0.05). A very strong positive correlation was found between body mass index (BMI) and PMOMV (r=0.758, p=0.011). A very strong positive correlation was found between amount of muscle resected (AOMR) and volume change (VC) and between AOMR and volume change percentage (VCP) in resected muscles (r=0.912, p=0.001 and r=0.878, p=0.001, respectively).