Hypertensive reactions to phenylephrine eyedrops in patients with sympathetic denervation

We studied the effects of topical phenylephrine eyedrops on systemic blood pressure in 298 patients about to undergo ocular surgical procedures by comparing their blood pressure on admission to the hospital with that measured immediately before surgery. The patients were divided into three groups. Group 1 consisted of 230 patients who had neither history of insulin-dependent diabetes nor prior teatment with reserpine or guanethidine. Group 2 included 41 insulin-dependent diabetic patients. Group 3 contained 27 hypertensive patients who had been taking reserpine or guanethidine. Patients in each group were divided into two subgroups (A and B). The 202 patients in the three A subgroups received preoperative phenylephrine eyedrops, whereas the 96 patients in the three B subgroups did not. All three B subgroups and Group 1A (176 patients) did not show significant increases in blood pressure. There was a statistically significant increase in both systolic and diastolic pressures in Group 2A (14 patients) and in Group 3A (12 patients). From this study, we concluded that administration of preoperative phenylephrine eyedrops can be hazardous in patients with long-standing insulin-dependent diabetes or in hypertensive patients receiving reserpine or guanethidine.