Comparison of subtenon's anaesthesia with peribulbar anaesthesia in manual small incision cataract surgery

Abstract

Ophthalmic surgery has been performed under a
wide range of anaesthetic techniques. The type of
anaesthesia for each ophthalmic surgery depends
on many factors like patient co-operation, the
nature of the surgery and surgeon's preference.
Peribulbar block involves injections above and
below the orbit, with local anaesthetic deposited in
the orbicularis oculi muscle. This technique blocks
the ciliary nerves, as well as CN III and VI, but does
not block the optic nerve (CN II). sub-tenon's block
has become the most common technique of orbital
regional anaesthesia in many centres. In this
technique, forceps are used to elevate the
conjunctiva and tenon's capsule and the needle is
directed posteriorly, and anaesthetic is injected in
the subtenon's space between the tenon's
capsule and sclera in the equatorial region of the
superotemporal quadrant of the eyeball. This
results in blocking of the ciliary nerves.