Session: Free papers Session VI - Vertical Strabismus

Evaluation of objective cyclodeviation following inferior oblique muscle weakening procedures for V-pattern strabismus.

Agata ORDON^1,2,3, Justyna SIMIERA^2,3, Piotr LOBA^2,3

¹Independent Public University Eye Hospital, Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
²Department of Binocular Vision Pathophysiology and Strabismus, Medical University of Lodz, Lodz, Poland
³Laser Eye Microsurgery Centre Clinic of Prof. Jerzy Szaflik, Warsaw, Poland

Introduction: The primary inferior oblique overaction (IOOA) manifests as excessive elevation in adduction and V-pattern strabismus, most commonly associated with infantile esotropia, accommodative esotropia, or intermittent exotropia. The most commonly used surgical procedures to treat IOOA are recession and anterior transposition. Cyclodeviation is defined as the rotation of an eyeball along the anteroposterior axis. The study aimed to assess changes in objective cyclodeviation after two different weakening procedures (inferior oblique muscle recession and anterior transposition) in cases of V-pattern horizontal strabismus with inferior oblique overaction.

Methods: Retrospective analysis of medical records of 19 subjects, 37 eyes (mean age: 10,89; range: 5-48) undergoing inferior oblique muscle recession or anterior transposition for IOOA. Objective cyclodeviation was measured employing fundus photography with the determination of the disc-foveal angle using Cyclocheck® software before and three months after the surgery. Cyclodeviation alterations (change in disc-foveal angle) were assessed and subjected to statistical analysis.

Results: Both procedures (inferior oblique recession and anterior transposition) resulted in significant changes in objective cyclodeviation (p<0.001 – inferior oblique recession, p=0.049 – anterior transposition). The mean reduction in excyclotorsion was 9.46° ± 7.96° (inferior oblique muscle recession) and 18.17° ± 14.58° (anterior transposition). Negative correlations were observed between the amount of muscle recession and change in cyclodeviation, as well as between preoperative excyclotorsion and change induced by inferior oblique recession.

Conclusions: Inferior oblique muscle recession and inferior oblique anterior transposition produce different changes in cyclodeviation in patients with IOOA and V-pattern strabismus. The amount of recession is well corelated with the change in objective cyclorotation.