Intracamerally injected mydriatic agents safer than standard eye drop regimen during cataract surgery performed in older patients.
Results of blood sampling
The mean patient age of the 30 patients who underwent blood sampling was 71.3 years (range, 51.3-85.5); most (80.0%) were older than 65 years. All of these patients received the standard regimen of mydriatics in both groups (except for one patient in the ICMA group who received another 100-microliter injection).
In the 15 patients in the ICMA group, tropicamide was not detected at 2, 12, and 30 minutes after injection but was detected in 73.3% of patients in the safety set group at 2 minutes and in all patients at 12 and 30 minutes (maximal plasma concentration, 3.16 nanograms/milliliter at 30 minutes in the safety set group).
Phenylephrine was detected in the ICMA group in two patients (maximal concentrations, 0.140 and 0.587 nanogram/milliliter) and in all 15 patients in the safety set at least one time point (range of maximal concentration between 0.109 and 1.42 nanogram/milliliter); in 38.5% of patients, the maximal phenylephrine concentration was over 0.59 nanogram/milliliter.
When the two groups were compared, the authors reported that more patients in the safety set group had a “meaningful increase” in hypertension and/or tachycardiac events, that is, 11.2% vs. 6.0% in the ICMA group, respectively, a difference that reached significance (p = 0.03).
The study results showed that the “ICMA result has lower systemic ocular surface exposure to phenylephrine and tropicamide than the … topical treatment. [The ICMA treatment] permits the correct dose of the appropriate agents to be administered consistently at a convenient time (at the start of surgery), in a safe and monitored environment (the operating room) at an appropriate site (anterior chamber) with less [cardiovascular] side effects compared to the usual dilation procedure,” the investigators concluded.
The authors reported their findings on behalf of the Intracameral Mydrane and Ethics Group in Clinical Ophthalmology (2019;13:811-819).
Jose Guell, MD
E: [email protected]
Dr. Guell is affiliated with the Autonomous University of Barcelona, Barcelona, Spain.