What method is used to anesthetize the iris directly?

Intracameral anesthesia is the method used to anesthetize the iris directly during ophthalmic procedures. This technique involves injecting an anesthetic agent into the anterior chamber of the eye, which allows for rapid and effective pain relief by directly affecting the structures within the eye, including the iris and the cornea.

This method is particularly useful in surgeries such as cataract extraction, where a quick onset of anesthesia is advantageous. The localized delivery of the anesthetic ensures that the tissue involved in the surgical process is numbed, facilitating a smoother surgical experience.

In contrast, other methods like subconjunctival injection primarily target the outer layers of the eye and may not effectively anesthetize deeper structures such as the iris. Retrobulbar anesthesia, while effective for more extensive ocular surgeries, encompasses larger areas and can involve risks such as nerve damage. Topical application is often used for surface-level anesthesia but does not adequately provide pain relief for deeper procedures involving the iris. Thus, intracameral anesthesia is deemed the most direct and effective method for this purpose.