Opththalmic Day Unit
Gas in your eye
At the end of your eye operation your eye was filled with a medical gas. Gas is commonly used in ‘vitrectomy’ eye operations to keep the retina in place whilst it is healing.
A vitrectomy is a surgical procedure that removes the clear, jelly-like fluid in the central cavity of the eye so that the retina can be operated on.
For the gas to have the right effect, it is necessary for you to keep your head in a certain position. You have received separate instructions as to what your individually prescribed head posture is, it will depend on where in your retina there is a tear.
This is the only way for the retina to heal properly and for your sight to improve.
The commonest postures are right side, left side or face down.
When will my sight come back?
For the first week you will only be able to see light and dark with your eye. This is because the gas makes everything badly out of focus. Some people are able to see objects held very close to the eye.
Following this, your sight will begin to return. The timing depends on the type of gas used. Short-acting gas (SF6) takes two to three weeks to disappear, long-acting gas (C3F8) takes about two months.
When the gas bubble is down to half the size you will see a horizontal line across your vision, bobbing up and down with head movement. This is where the gas meets the fluid which is gradually replacing it. It is just like a spirit level. You will have sight above this line and blackness below it.
Day by day this line will move lower down gradually, the area of sight will get bigger and the black area will get smaller until it is just a circle at the bottom of your vision. Eventually the black area will disappear.
Do I need to return to clinic?
NAs the gas is naturally replaced by fluid, you will need regular eye examinations at the clinic. This is to make sure that those areas of the retina no longer covered by gas remain in place.
The usual time intervals are weekly for short-acting gas, and once every three or four weeks for long-acting gas. Occasionally, the retina can become loose (detached) whilst the gas is leaving the eye or shortly afterwards.
If you need a general anaesthetic for another operation while you still have gas in your eye, it is very important that you let the anaesthetist know about the gas. The anaesthetist must not use nitrous oxide gas during the anaesthetic. Nitrous oxide moves into the gas bubble and can cause a dangerous rise in pressure in the eye.
You must not fly in an aircraft while there is gas in your eye. The pressure in the cabin of an aircraft is dropped to about two thirds of the normal atmospheric pressure. If there is a gas bubble in your eye this will expand to one and a half times its size with a corresponding rise in pressure in your eye.
This would be very painful and can lead to loss of sight.
The same thing, but to a lesser extent, happens if you travel by road across mountains. (For example this could be travelling across the pennines to the Lake District). You may feel some pain in your eye as you reach higher altitudes, as you travel down the other side the eye becomes comfortable again.
If you have any problems please contact:
• Eye day unit on 01642 854556
• Eye casualty on 01642 854096
South Tees Hospitals NHS Foundation Trust would like your feedback. If you wish to share your experience about your care and treatment or on behalf of a patient, please contact The Patient Experience Department who will advise you on how best to do this.
This service is based at The James Cook University Hospital but also covers the Friarage Hospital in Northallerton, our community hospitals and community health services.