oculocardiac reflex in laser in situ keratomileusis

background: this study was conducted to evaluate variations in heart rate and to determine the occurrence of oculocardiac reflex (ocr) during laser in situ keratomileusis (lasik). methods: this descriptive, prospective study was designed to observe the effect of suction ring and ablation stages during lasik procedure on the heart rate. the ecg was taken before and during lasik operation on the first eye in 61 patients. these patients were selected randomly among cases that presented to al-zahra hospital, isfahan, iran for lasik surgery in summer 2001. all patients were healthy without history of cardiovascular disease and no systemic medication. the ecg prior to the procedure was considered as baseline. decrease in the heart rate of 10% or more of baseline was considered as oculocardiac reflex. results: in 12 patients (20%) the heart rate decreased more than 10% during the suction ring stage. in 19 patients (31%) the heart rate increased more than 20% of baseline. in 15 patients (25%) the heart rate increased 10%-20% more than baseline during the preparation and ablation stages. in the remaining 15 patients (25%) the heart rate did not change during the procedure. conclusions: results of this study confirm that oculocardiac reflex may occur during the lasik procedure especially in the suction ring stage. because the oculocardiac reflex may cause heart rate changes during lasik, the patients should be closely monitored during the procedure. key words: laser in situ keratomileusis, oculocardiac reflex, suction ring.