Subconjunctival injection in the lower fornix is safer than sub-Tenons (infra-Tenons) or so-called periocular injection. Subconjunctival injection under the bulbar conjunctiva is potentially dangerous. Myopic eyes are more likely to be penetrated than emmetropic or hyperopic eyes because of greater ocular length, thin sclera, and staphylomas. Injections should be performed with patient supine. Viscous lidocaine provides better anesthesia than topical anesthesia. Both physicians’ hands should be braced against the patient’s facial bones with the needle entering laterally and nearly parallel to the lid margins. If the needle is directed posteriorly, the globe can be penetrated if the patient moves forward.

Topical and intraocular anesthesia is rapidly increasing in popularity for cataract surgery. Although some straightforward core vitrectomy procedures can be performed with topical anesthesia, the extraocular muscles must be blocked for macular and complex surgery. Peribulbar anesthesia using a blunt, curved, flexible cannula and small conjunctival incision are theoretically safer than multiple injections into the anterior orbital tissue. The patient should be directed to position the eye in the primary position during retrobulbar injection. This position has been shown by Grizzard to minimize displacement and increased tension on the optic nerve, which increase the risk of penetration of the nerve (4).