Anaesthetic

A local anaesthetic usually works very well at preventing the feeling of pain during an operation on the eye. It also provides pain relief for several hours after the operation.

It has fewer risks and side effects than a general anaesthetic, especially if you have other medical conditions. This is because it doesn’t affect other parts of your body , such as your breathing or your heart.

You are likely to recover more quickly following surgery under local anaesthetic and can usually go home on the same day. You can also continue to take most of your usual medicines and can eat and drink as normal.

There are two types of local anaesthetic:

• Local anaesthetic eye drops that numb the eye
• Local anaesthetic injections. Drops are give first to numb the surface of the eye, then an injection is given near to the eye but not into the eyeball itself.

We will decide on the type of local anaesthetic that is best for you, based on your eye assessment.

This varies from person to person. Eye drops that numb the surface of the eye are used first, to make it as comfortable as possible. A very fine needle is then used to give you an anaesthetic injection into the tissues surrounding the eye. This may cause a feeling of stinging or pressure, but usually lasts less than a minute.

Reasons why a local anaesthetic might not be suitable

To have this operation under a local anaesthetic you will need to be able to

• lie reasonably flat and still for 15-20 minutes.
• feel confident following instructions during the procedure.

Both anaesthetists and eye surgeons are trained to give local anaesthetic

Local anaesthesia for eye surgery is the safest aesthetic for many people.

You may develop bruising or a black eye, as the injection may damage a small blood vessel around your eye. This is not usually serious, but can look unsightly for a week or so. It is more common if you take aspirin or other drugs that thin the blood.

Rarely, bleeding after the injection can cause problems around the eye.

Serious complications, such as significant damage to the eye, blood vessels or eye muscles, and serious effects on your heart, blood pressure and breathing can happen, but these are either rare or very rare.

Your eyelid will be kept closed, to prevent anything touching and damaging the surface of your eye. Staff may massage your eye, apply pressure or place a small weight on your closed eye, to help the aesthetic spread evenly.

Your anaesthetist or eye surgeon will check your eye to make sure it is numb. You may be asked to look in different directions, to assess the effects of the anaesthetic has worked, you will be taken into the operating theatre.

No, it is best not to speak whilst the surgeon is operating on your eye, as this will make your face move and could affect the surgery. If you want to say something, you will be asked to move your hand gently and the eye surgeon will stop operating so that you can speak.

You will hear the surgeon speaking to the theatre team during the operation. The equipment in the theatre will make gentle continuous sounds and the heart monitor may “bleep”

You will able to see bright lights and you may see some movement during the operation. This varies from person to person. You will not be able to see any detail.

The surgeon operates with fine instruments that reach inside your eye. Your eye is not removed from its normal position.

While the surgeon is working, you may feel touch and pressure. You should not experience any pain. If you are uncomfortable you must let theatre staff know, so they can give you more local anaesthetic, if needed.

A small clip is used to keep the eyelid of the eye being operated on open, so you do not need to worry about blinking. We will frequently moisten your eye during the operation, so your eye doesn’t become dry.

You are likely to need to remove your hearing aid if it is on the same side as the eye being operated on. This is because, even with care, water can enter the ear, causing the hearing aid to malfunction and start to make noises.

You should continue to take all of your prescribed medications as normal.

It is injected into a vein in the back of the hand or arm (intravenously), through a fine plastic tube called a cannula.

An anaesthetist will always be the clinician responsible for giving sedation during an operation involving combined local anaesthetic and sedation.

Sedatives can sometimes affect breathing, so while you are sedated the anaesthetist will constantly monitor the amount of oxygen in your blood with a small device on your finger. You may be given extra oxygen through a facemark or small plastic tubes under your nose.

After a local anaesthetic with sedation you will usually be able to go home when you feel ready, often within a couple hours after surgery.

Sedation temporarily affects your coordination and reasoning skills, so you must not drive, drink alcohol, operate machinery, make important decisions or sign legal documents for 24 hours afterwards.

After 24 hours, if you are in any doubt about your ability to drive, please contact your motor insurer so you are aware of their recommendations, and always follow your surgeon’s advice.

What are the risks of sedation?

Sedation is frequently used and generally safe. However, for you to make an informed decision and give your consent, you need to be aware of the possible side effects and the risk of complications.

Side effects of sedation vary, depending on which sedative is used. After sedation you may get a headache, feel sick or vomit. You may experience a drop in blood pressure or temporary loss of muscle control, causing limb weakness. You may also feel confused, may not remember the operation and may be tired or light-headed the following day. All of these symptoms are usually short lived and go within 24 to 48 hours.

Complications of sedation include:

Toxic reactions

Sign of a toxic reaction include tingling lips, ringing in the ears, drowsiness and slurred speech. Rarely this can lead to an arrhythmia (a disturbance of the normal heartbeat) and heart attack.

Low oxygen levels in the blood

This can cause breathless and confusion.

Complication of sedation include:

• Toxic reactions

Signs of a toxic reaction include tingling lips, ringing in the ears, drowsiness and slurred speech. Rarely this can lead to and arrhythmia ( a disturbance of the normal heartbeat) and heart attack.

• Low oxygen levels in the blood

This can cause breathlessness and confusion.

You will have various tests at the pre-operative assessment clinic, to make sure it is safe to give you a general anaesthetic. You will also need to :

• Not eat or drink (to be “nil by mouth”) in the hours before the operation. We will give specific and clear instructions about when to stop eating and drinking before your operation. This is usually 6 hours before your admission time for food and 2 hours before for clear fluids. These instructions are important. if there is food or liquid in your stomach during your general anaesthetic, it could come up into your throat and damage your lungs.
• Stop smoking (if you smoke) a few days before the operation or stop altogether if you can. If this is not possible, try to cut soon the number of cigarettes you smoke each day. You should not smoke on the day of your operation. By stopping smoking you will help your recovery and, most importantly, your breathing after surgery.
• Follow the specific instructions about your medications from the pre-operative assessment team. Most medicines should be continued before and operation, but there are some which will definitely need to be stopped.

if you feel unwell when you are due to come into hospital, please let us know.

There are two ways of giving a general anaesthetic:

• Anaesthetic drugs may be injected into a vein in the back of the hand or arm (intravenously), through a fine plastic tube (cannula)
• You can breathe anaesthetic gases and oxygen through a mask, which you may hold if you prefer.

When you become unconscious, the anaesthetist will stay with you at all times. They will continue to give you drugs to keep you anaesthetised throughout the operation.

Side effects and complications of general anaesthetic

In modern anaesthesia serious problems are uncommon.

Risk cannot be removed completely, but modern equipment, training and drugs have made it a much safer procedure in recent years.

Common side effects:

• Feeling sick and vomiting after surgery
• Dry Throat
• Dizziness, blurred vision, headache
• Bladder problems
• Damage to the lips or tongue from the breathing tube (if used) – this is usually mine
• Itching, aches, pains and backache
• Pain during injection of drugs
• Bruising and soreness at the site of the intravenous cannula insertion
• Confusion or memory loss

Uncommon side effects and complications:

• Chest infection
• Damage to teeth from the breathing tube (if used)
• An existing medical condition getting worse
• Nerve damage to peripheral nerves (hands and feet)
• Awareness (becoming conscious during your operation)

Very rare complications:

• Heat attack or stroke
• Serious allergy to the anaesthetic drugs
• Damage to nerves in the spine

Death caused by general anaesthesia  is very rare. These are probably about five deaths for every million general anaesthetics in the UK.