Retrobulbar Injection

1. Clean the skin of the lower eyelid and upper cheek around the area of the inferior orbital rim with an alcohol swab.
2. With the patient in primary gaze, use a 1.25-inch 25- or 27-gauge needle (preferably a short-beveled blunt retrobulbar needle) to penetrate the skin just superior to the inferior orbital rim in line with the lateral limbus.
3. Advance the needle parallel to the orbital floor. After passing parallel to the equator of the globe, redirect the needle superonasally into the muscle cone.
4. Lateral motions of the needle are made to ensure that the needle has not penetrated the sclera (at which point, the lateral motion would be inhibited).
5. Pull back on the syringe to ensure no vascular structures have been penetrated. If no aspiration occurs, slowly inject the contents of the syringe. In a successful injection, the globe may move anteriorly due to the retrobulbar pressure.
6. Withdraw the needle along the same contour as insertion. May perform orbital compression for at least 2 minutes.

Subtenon Injection

1. Apply topical anesthesia to the area to be injected (e.g., topical proparacaine or a cotton-tipped applicator soaked in proparacaine, or both, held on the area for 1 to 2 minutes). Place a drop of topical 5% povidone-iodine on the surface of the eye. If subtenon steroids are to be injected, 0.1 mL of lidocaine may be injected in the same manner as described next, several minutes before the steroids. The inferotemporal quadrant is usually the easiest location for injection.
2. With the aperture of a 25-gauge, 5/8-inch needle facing the sclera, the bulbar conjunctiva is penetrated 2 to 3 mm from the fornix, avoiding conjunctival blood vessels.
3. As the needle is inserted, lateral motions of the needle are made to ensure that the needle has not penetrated the sclera (at which point, the lateral motion would be inhibited).
4. The curvature of the eyeball is followed, attempting to place the aperture of the needle near the posterior sclera.
5. When the needle has been pushed in to the hilt, the stopper of the syringe is withdrawn to ensure that the needle is not intravascular.
6. The contents of the syringe are injected, and the needle is removed.

Subconjunctival Injection

1. Apply topical anesthesia and antiseptic as above.
2. Forceps are used to tent the conjunctiva, allowing the tip of a 25-gauge, 5/8-inch needle to penetrate the subconjunctival space. The needle is placed several millimeters below the limbus at the 4- or 8-o’clock position, with the aperture facing the sclera and the needle pointed inferiorly toward the fornix.
3. When the entire tip of the needle is beneath the conjunctiva, the stopper of the syringe is withdrawn to ensure that the needle is not intravascular.
4. The contents of the syringe are injected, and the needle is removed.

NOTE:

An eyelid speculum may be helpful in keeping the eyelids open during subtenon and subconjunctival injections.