Anaesthesia for Eye Surgery
The options for anaesthesia in eye operations include:
Local anaesthetic without sedation
Local anaesthetic with sedation
General anaesthetic
Each anaesthetic option has different risks, advantages and disadvantages. These are summarised below.
Local Anaesthetic (LA)
This involves the injection of an anaesthetic just under the skin in the area of the tumour. The injection can be quite painful (a bit like a dental injection). It will numb the area and then you will not feel pain during the operation, although you may feel a little bit of pressure. The sensation will return in about 2-3 hours. The local anaesthetic (and the surgery) often cause bruising which usually takes up to a week to resolve.
LA is the safest way of having an operation. There is a small risk of minor complications such as nausea, tremor, agitation or dizziness (about 1% risk for each of them). There are tiny risks of serious complications including abnormal heart rhythms (cardiac dysrhythmia) and severe impairment of the central nervous system (brain). These could cause heart attacks, strokes, or breathing difficulties, potentially causing death. These are, however, extremely rare when appropriate doses are used.
Less serious complications include persistent pain around the injection site, blurred or double vision, low blood pressure, light-headedness and nerve damage. These are also very rare and almost always recover completely.
Most patients go home the same day of surgery (‘daycase’) and unlike sedation and general anaesthesia (see below) you usually do not require anyone to be at home with you on the first night after surgery.
Sedation
This is an injection into a vein of a drug that will make you a more relaxed and sleepy. It is given by an anaesthetist and your heart and breathing are monitored as if you are having a general anaesthetic (see below). With sedation you will be asleep or very sleepy during the local anaesthetic injection, so that you do not feel the pain of the injection and may remain relaxed or sleepy during the rest of the operation.
Side effects and complications of sedation include headache (either during or afterwards), sore or dry throat and lips, nausea and rarely vomiting, faintness or dizziness, or drowsiness (about 1 in 3) afterwards especially when you start to move around and falls in blood pressure.
Less common side effects and complications of sedation include general weakness and muscle aches and pains. Some people may develop a mild allergic itch or rash.
Very rare but serious complications include pneumonia (which can be caused from stomach contents being aspirated into the lungs during an episode of vomiting), epileptic seizures, blood clot in the lungs, severe allergic reactions (anaphylaxis), heart attack and stroke, which may cause death.
You can still go home the same day of surgery if you have sedation, but you will need to ensure that there is someone at home with you the first night after surgery.
General Anaesthetic (GA)
A GA means you are unconscious throughout the operation. The GA is administered by an anaesthetist who will monitor your heart and breathing (or the breathing is done for you by a machine) throughout the operation. You will wake up after the procedure and you may need to stay in recovery for a few hours while you are being monitored.
There is a greater but still very small risk of serious complications with GA. These include teeth injuries while an instrument (laryngoscope) is inserted into your mouth (1 in 100), sore throat (which usually recovers within a few days), blindness (1 in 250,000) or even death (1 in 50,000, but even lower risk if you are healthy and higher risk if you have significant other medical conditions, e.g. of the heart, lungs or brain, or obesity).