peribulbar

Peribulbar refers to the region around the eyeball within the orbit. In ophthalmology, the term is used for a regional anesthetic technique in which local anesthetic is deposited into the peribulbar space to block sensory nerves and immobilize the eye for surgery.

The peribulbar space is extraconal, surrounding the globe between the orbital walls and Tenon’s capsule. Anesthetic is usually injected under sterile conditions, commonly via inferotemporal and/or superotemporal approaches. Local anesthetics such as lidocaine, bupivacaine, or ropivacaine are used, often with hyaluronidase and sometimes adrenaline, to provide anesthesia and akinesia. Onset is variable but typically minutes.

Indications include cataract extraction, retinal procedures, and some strabismus surgeries. The technique is designed to provide analgesia and eye immobilization while reducing the risk of globe perforation and brainstem anesthesia compared with retrobulbar blocks.

Complications include conjunctival chemosis, subconjunctival hemorrhage, periorbital edema, ptosis, diplopia, and transient intraocular pressure rise. More severe but uncommon risks include orbital hemorrhage, infection, nerve injury, globe perforation, and systemic local anesthetic toxicity if intravascular injection occurs.

Peribulbar anesthesia remains a common alternative to retrobulbar anesthesia, chosen for safety and patient tolerance, though some practitioners use both techniques depending on anatomy, surgeon preference, and risk assessment.