Sensory heterotropia: Which eye should be the main site of surgery, sound or amblyopic eye?

Abstract

Introduction The altered tonic vergence movement in sensory heterotropia may make the preoperative measured angle of deviation inconstant, and the surgical results are less predictable than when visual acuity is normal in each eye. Maintaining the postoperatively corrected position of the amblyopic eyes is considered difficult because the brain has lost interest in those eyes' position. Objective The aim of this study was to compare the postoperative results and their stability in patients undergoing surgery mainly on the sound eyes with those undergoing surgery mainly in the amblyopic eyes in case of sensory heterotropia. Design This prospective nonrandomized comparative study was carried out in the Ophthalmology Department, Minia University Hospital during the period from March 2011 to October 2012. Patients and methods Sixty patients were included in this study and were divided into two equal groups according to the type of horizontal deviations. In each group, half of the patients underwent surgery mainly on the sound eyes and the others underwent surgery mainly on the amblyopic eyes, and the results were compared. Results In patients of group 1 (esotropia) who underwent surgery mainly on the sound eyes, there were significantly higher and stable results than those who underwent surgery mainly on the amblyopic eyes after 1 and 6 months. Patients of group 2 (exotropia) who underwent surgery on the sound eyes had significantly higher and stable results than those who underwent surgery on the amblyopic eyes after 6 months only. Conclusion Surgery on the sound eyes mainly in horizontal sensory heterotropia had better and more stable results than surgery on the amblyopic eyes.