Background & Objectives: Oculocardiac reflex (OCR) is presented with bradycardia and other arrhythmias, is induced by mechanical stimulation and therefore, encountered during strabismus surgery. The aim of this study is to determine the incidence and risk factors of cardiac arrhythmias during strabismus surgery in children and adults.

  Methods: In this prospective, randomized and double-blind study, 46 patients ASA class I and II underwent elective strabismus surgery with general anesthesia and were allocated to one of the two groups: children under 12 and adults over 12. All patients received standard general anesthesia based on their age. Demographic data, type of involved muscle, the incidence, (type and frequency) and the cause of arrhythmias and skillfulness of the surgeon (professor-assistant) were recorded.

  Results: There were 26 patients in children group and 20 patients in adult group. The overall incidence of arrhythmias was 91% with 96.15% in children and 85% in adults. There was not any significant difference in the incidence of arrhythmias, and the mean rate of occurence between two groups. Most of the arrhythmias were due to external ocular muscles traction. Conjunctival traction and pressure on the globe were the other causes. Stimulation of median rectus muscle as the most important arrythmogenic factor was seen in 13 children and 12 adults. Bradycardia and tachycardia were among common arrhythmias, but there was no significant difference between two groups (P>0.05) in terms of their incidence.

  Conclusion: This study showed that the incidence of arrhythmias during strabismus surgery is high in both children and adults. This reflex does not often lead to hemodynamic compromise, however, for its early diagnosis and treatment, close and continuous monitoring of the patient as well as cooperation and communication between anesthesiologist and surgon is needed.