Sir,

A culture of caution pervades in the perioperative use of intracameral phenylephrine (I/C PE) for patients with cardiovascular comorbidities. We sought to assess its safety by investigating whether it confers any clinically significant cardiovascular effect, specifically on blood pressure.

Study

A prospective interventional study design was employed. Patients were included in the study whether or not they suffered from cardiovascular risk factors. Overall, 421 patients were administered 0.25 ml of I/C PE 2.5%, and blood pressure readings were taken before and after intracameral administration. Data were analyzed using the paired t-test.

Outcomes

The mean systolic and diastolic blood pressures rose by 2.7 and 0.8 mm Hg post-I/C PE administration, respectively. Neither the systolic nor the diastolic blood pressure changes were statistically significant. The mean of the mean arterial pressures recorded a minor but statistically significant (P=0.015) rise of 1.4 mm Hg, from 106.6 mm Hg to 108.0 mm Hg. We therefore concluded that I/C PE in the specified dose of 0.25 ml of 2.5% has negligible and clinically insignificant effects on blood pressure, and can be safely used during cataract surgery.

Comment

Intracameral administration of mydriatics provides several advantages compared with topical ones, including a more rapid and sustained effect, less glare and discomfort, and increased cost-effectiveness. This makes it useful not only as an alternative, but also as an adjunct for patients with poor topical mydriasis. One particular concern with topical instillation is the greater systemic absorption, which has been demonstrated to carry potential cardiovascular risk.1 Hypertension is a comorbidity for half of patients undergoing cataract operations, and even if medically controlled these patients are already at risk of preoperative rises in blood pressure.2

Similar studies investigating the blood pressure effects of intracameral adrenaline found no intraoperative fluctuations in blood pressure as compared to or as adjuncts to topical mydriatics.3, 4 The only existing literature regarding complications of I/C PE indicates that its use is not associated with any statistically significant changes in surgical outcomes,5 although the study in question did not directly measure the circulatory effects. Group sizes for these studies were limited, ranging from 25 to 50.