Retrobulbar block

A retrobulbar block is a regional anesthetic nerve block in the retrobulbar space, the area located behind the globe of the eye. Injection of local anesthetic into this space constitutes the retrobulbar block. This injection provides akinesia of the extraocular muscles by blocking cranial nerves II, III, and VI, thereby preventing movement of the globe. Cranial nerve IV lies outside the muscle cone, and therefore is not affected by the local anesthesia. As a result, intorsion of the eye is still possible. It also provides sensory anesthesia of the conjunctiva, cornea and uvea by blocking the ciliary nerves. This block is most commonly employed for cataract surgery, but also provides anesthesia for other intraocular surgeries.