Extraocular muscle resection, recession length and surgery outcome modelling in strabismus treatment: a pilot study

Abstract

BackgroundMany surgical formulas have been developed and proposed based on the experience of surgeons to improve the predictability of strabismus surgery. However, the consent among strabismus surgeons regarding the dose effect of the extraocular muscle (EOM) recession or resection was not achieved yet and the disagreement about the appropriate amount of strabismus surgery still exists.ObjectiveOur study aimed to propose an instrument for EOM resection (RsL) and recession length (RcL) estimation before the surgery and second to elaborate an postoperative angle of deviation (PAD) predictive model using simple potential predictors.Methods and AnalysisThe analytical prospective clinical study was conducted from April 2016 to July 2019, on a sample of 216 patients (aged between 2–58) with concomitant strabismus who underwent strabismus surgery in Clinical Republican Hospital ‘Timofei Mosneaga’and Children Hospital ‘Em Cotaga’ from Republic of Moldova. The correlations of patients’ age, strabismus type, amblyopia degree, RsL, RcL, preoperative angle of deviation (PreAD) with PAD were estimated using Pearson’s correlation analysis. Multiple linear regression analysis, multicollinearity analysis and residual analysis were performed.ResultsThe EOM RsL was predicted using strabismus type, patient’s age, PreAD and EOM RcL. EOM RcL, in turn, was estimated by the similar covariates set, instead of RcL being RsL. PAD modelling showed the PreAD, EOM RsL and EOM RcL predictive ability for strabismus surgery outcome prediction.ConclusionIn our study, we propose four mathematical models as potential instruments for EOM RsL, EOM RcL and PAD modelling in esotropia and exotropia surgery.

Evaluation of Factors Affecting the Outcomes of Strabismus Surgery and Treatment of Amblyopia

“…In all cases treated for amblyopia, visual acuities at the beginning and end of treatment were converted to logMAR equivalents, and the amount of increase in visual acuity was also calculated with logMAR values. A spherical or cylindrical refractive error difference of at least 1 diopter or more was taken as the criterion for anisometropia 6 . The refractive error in both eyes and the difference in refraction between the eyes were calculated by converting them to spherical equivalent with the formula 'spherical value + cylindrical value/2' 6 .…”

“…Strabismus and amblyopia are typically considered preventable vision loss if diagnosed and treated early 5 . Strabismus affects 4% of the population and causes negative effects in many areas including quality of life and psychosocial aspects in children 6 . Amblyopia is a unilateral or bilateral reduction in visual acuity in the entire optic axis and macula without any organic cause that can decrease vision which can be detected by physical examination [7][8][9] .…”