Evaluation of the effect of combined Z-tenotomy and conventional recession of the lateral rectus for correction of comitant exotropia

Abstract

Background Strabismus is a frequent ocular condition seen in optometry and ophthalmology clinics. In the United States, 3–5% of children are affected, with 126 400 new instances being reported each year. Aim The purpose of the study was to evaluate the effect of Z-tenotomy of lateral rectus when combined with conventional recession for correction of exotropia. Patients and methods This is a prospective, institutional clinical trial study that included 40 patients and took place at the Ophthalmology Department of Tanta University Hospital. Results The research was completed on 40 patients at any age and moderate-angle to large-angle comitant exotropia without any vertical deviations and who met the inclusion criteria. They were divided into four groups: group A patients had exotropia of angle of 20–30 prism diopters (PD), where one lateral rectus muscle was recessed 7–8 mm; group B patients had exotropia of angle of above 30–40 PD+where one lateral rectus was recessed 7–8 mm combined with Z-tenotomy; group C patients had exotropia of angle of above 40–50 PD, where both lateral rectus were recessed 7–8 mm, and group D patients had exotropia of angle of above 50–70 PD where both lateral rectus were recessed 7–8 mm combined with Z-tenotomy. Conclusion Z-tenotomy of lateral rectus combined with conventional recession 7–8 mm procedure appears to have augmented the effect of recession procedure while avoiding the risk of limiting ductions in the field of recessed muscle.