Proper Dosing of Intracameral Phenylephrine for Mydriasis and IFIS Is Key

Intracameral (IC) phenylephrine is often used to prevent intraoperative floppy-iris syndrome (IFIS) and initiate mydriasis during cataract surgery, but as the drug is known to have cardiovascular effects proper dosing is important.

Study Design

The authors conducted a systematic literature review of English-language articles published before March 2023 related to the risk of systemic adverse events (AEs) with IC phenylephrine administration and the optimal dosage of IC phenylephrine for mydriasis. Sixteen studies were included in the review.

Outcomes

In the 16 studies, there was very little evidence of systemic AEs noted with IC phenylephrine use. Total dosages across the formulations ranged from 0.78 to 25.0 mg. The use of a lower phenylephrine concentration (0.31%), in addition to an anticholinergic and lidocaine, appeared to be best for initial mydriasis. A higher concentration (1%–1.25%) may be required for the management of IFIS.

Limitations

Limitations include potential underreporting of systemic AEs with IC phenylephrine in the reviewed studies and insufficient data on optimal dosing and concentrations of IC phenylephrine for different purposes (e.g., initial mydriasis vs IFIS management). Also, the study did not directly address limitations of the reviewed research, such as sample sizes, lack of long-term follow-up, and data collection biases.

Clinical Significance

Overall, this review provides guidance on the practical use of IC phenylephrine to facilitate cataract surgery. Intracameral phenylephrine appears to be safe and effective for achieving mydriasis during cataract surgery, especially in patients with IFIS; however, more research will need to be done to determine the optimal concentration and dosage.

Financial Disclosures: Dr. Nisarg Chhaya discloses no financial relationships.