Download Anaesthesia for Eye Surgery

ABSTRACT – Anaesthesia for Eye Surgery - NSC 2014
Ralph de Plater
Cataract extraction and insertion of intra ocular lens is the most commonly performed eye
operation throughout the world in 2014.
A cataract is a clouding of the lens - limiting vision.
The word cataract comes from the Greek, meaning waterfall. Until the mid-1700s, it was thought
that a cataract was formed by opaque material flowing, like a waterfall, into the eye.
Techniques of displacing a mature cataract into the vitreous by blunt trauma or instruments are
described over two thousand years ago, and there are drawings in ancient times of sharp objects
entering eyes to relieve blindness. The first reported surgical removal of a cataract from the eye
occurred in Paris in 1748.
These procedures were performed using restraint or stupor brought on by inhalation of ethers,
ingestion of opiates or alcohol, or cerebral ischaemia from carotid artery compression.
From 1846, general anaesthesia was available for eye surgery but because of vomiting, straining
and bucking and congestion of the eye or fighting with the anaesthetist for access, many
ophthalmologists preferred alcohol, opium and restraint.
In 1884 Karl Koller transformed ophthalmic surgery with the topical application of cocaine.
And Knapp in the same year described a form of deeper (regional) anaesthesia using cocaine.
For the last 130 years, topical anaesthesia, regional anaesthesia and general anaesthesia have
been employed for ophthalmic surgery. All of these techniques have advanced over time –
sometimes a significant advance in one technique slowing an advance in the others.
In 1928, the endo tracheal tube enabled a secure airway and allowed the anaesthetist to be at a
distance to the surgical field. Intermittent Positive Pressure Ventilation allowed better control of
physiological conditions within the eye.
Between 1930 - 1990 topical anaesthesia fell out of favour because patients could squeeze their
eyelids and move their eyes and operative techniques at that time utilized large incisions, thus
jeopardizing the eye. There was a resurgence of interest in topical anaesthesia with small incision
surgery and phacoemulsification.
In the 1980’s, anaesthetists provided sedation and monitoring of patients when regional blocks
were performed by eye surgeons. Some anaesthetists participated further by performing eye
blocks themselves, initially retrobulbar, then peribulbar after Davis’ description of the technique
in 1986. Regional local anaesthesia continued and continues to play a significant role,
complimented by the rediscovery and description of the subtenons technique in the 1990’s.
In 2014, although cataract extraction and insertion of intra ocular lens is the most commonly
performed eye operation, anaesthesia for eye surgery is about so much more.
We are able to provide anaesthesia for minimally invasive small incision high turnover cataract
lists, but also for sight saving complex vitreoretinal and glaucoma drainage cases. We may assist
to preserve useful sight for many years or a lifetime. We may anaesthetize for life saving ocular
tumour surgery. We assist people to see more clearly so that they can read or do crosswords, to
drive more safely or to function without glasses.
Topical anaesthesia is fast and simple, but limited.
Regional anaesthesia may provide optimal operating conditions, but there may be significant
complications.
General anaesthesia is reliable, does not require patient co-operation and avoids the
complications of local anaesthesia - but is general anaesthesia.
In 2014, anaesthesia for eye surgery means administering with due consideration and skill the
most appropriate anaesthetic – topical, regional or general – giving consideration to the patient,
the operation, the surgeon, the time and the place.