Ocular Anasthesia - Peribulbar Block

Ocular Anasthesia ( Peribulbar Block)

Ocular surgery may be performed under topical, local or general anaesthesia. Local anaesthesia is more frequently employed as it entails little risk and is less dependent upon patient’s general health.

It is easy to perform, has got rapid onset of action and provides a low intraocular pressure with dilated pupil. Above all, in developing countries like India, with a large number of cataract cases, it is much more economical

Peribulbar block

This technique described in 1986 by Davis and Mandelhas almost replaced the time-tested combination of retrobulbar and facial blocks, due to its fewer complications and by obviating the necessity for a separate facial block.

Primarily the technique involves the injection of 6 to 7 ml of local anesthetic solution within the peripheral space of the orbit, from where it diffuses into the muscle cone and lids; resulting in globe and orbicularis akinesia and anaesthesia.

Classically, the peribulbar block is run by two injections; first through the upper lid (at the junction of medial one-third and lateral two-third) and second through the lower lid (at the junction of lateral one-third and medial two third.

After injection orbital compression for 10 to fifteen minutes is applied with super pinky or the other method. 

The anaesthetic solution used for peribulbar anaesthesia consists of a mix of two per cent lignocaine, and 0.5 to 0.75 per cent bupivacaine (in a ratio of 2:1) with hyaluronidase 5 IU/ml and adrenaline one in one lac.