An examination of your eyes has shown that your diabetes is affecting the small blood vessels in your retina and that you are at risk of long-term problems with your sight.
If you have not already done so, you should read ‘Diabetic retinopathy – the facts’, which explains these changes in more detail.
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The aim of laser treatment is to stabilise the changes caused in your eyes by your diabetes. The treatment does not generally improve your sight although in some cases it might.
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A course of laser treatment may involve one or more visits to the laser clinic before the changes are controlled.
You will usually receive the treatment at an outpatient clinic.
Your sight will be checked and eye drops will be used to dilate both your pupils, although you may only have treatment to one eye at each visit. For this reason, you should not drive – get a lift to and from your laser appointment.
After the doctor has examined your eyes and you have agreed on the treatment and signed the form giving your permission (consent form), you will be taken through to the laser room.
Drops will be put into your eyes to numb the surface and then a special contact lens will be placed on the eye to hold your lids open and to focus the laser beam onto your retina. The lens will be removed after you have had the treatment.
The laser treatment involves focusing an intense beam of light onto your retina in small spots. The number of spots will vary according to the type of diabetic change you have and how severe the changes are.
Your eye will get used to the brightness during the treatment but at the end you will be dazzled and your sight will seem darked for several minutes. You should bring dark glasses to wear to go home after the treatment.
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Your sight will normally return to its previous level over the next few hours and you will be able to continue y our work or normal activities the next day.
Rarely, your sight can take longer to return to normal.
If you have had a lot of treatment, your eyes may ache. You should find that mild painkillers, such as paracetamol and aspirin, ease the pain.
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Usually the treatment is not painful.
Sometimes the treatment will cause a sharp pricking feeling when certain areas of the retina are treated. This will happen where nerves run under the retina. The doctor who is giving your laser treatment cannot see these nerves.
If you have had a number of laser sessions in the past you may feel some discomfort during the treatment.
If you have felt discomfort in the past ask the doctor to give you painkillers or a mild sedative before the treatment starts, or take these yourself an hour before your appointment.
You should get medical advice if you have any new eye problems after your laser treatment.
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If you have proliferative retinopathy (new blood vessels on the retina) or if the doctors think you will very soon have proliferative retinopathy, the doctor will apply a large number of laser burns to the outer part of your retina, the part of the retina that allows you to see to the side and in the dark.
This treatment is called peripheral scatter laser photocoagulation.
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At the end of a course of treatment for proliferative retinopathy, the following may apply:
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Over half of people treated notice some difficulty with their night vision
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One in five people notice some loss of peripheral vision (the outer field of vision) in one or both eyes and three in 100 (3%) people have to stop driving because their peripheral vision has been reduced (tunnel vision)
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If you need an intensive course of laser treatment to control the changes in your eyes, you may notice a temporary worsening of your sight due to the macula (the small, highly sensitive central area of the retina) becoming waterlogged. This should sort itself out, but needs treatment in a small number of cases
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Occasionally, some people have a bleed into the jelly that fills the eye (the vitreous). If you notice a shower of floaters (specks that float across your vision) or your sight gets worse you should get medical advice.
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If you have macular changes, the doctor will apply gentle laser burns close to the central part of the retina – the part that you use for seeing clearly.
You need much less laser treatment than for proliferative retinopathy.
We may apply laser burns in a grid pattern over the area or they may be aimed directly at the leaking area.
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Complications are very rare for maculopathy treatment.
Some people can still ‘see’ the laser grid pattern after treatment. Usually this continues for up to two months and, very occasionally, for up to six months after treatment.
In a national survey, around one in 10 people reported seeing a small but permanent blind spot close to the centre of their sight.
The chance of you completely losing your central vision after laser treatment for maculopathy is around one in 300 (0.3%).
The doctor cannot completely avoid accidental laser burns to the very centre of your vision. You may find it difficult to keep still or may accidentally look at the laser as it fires. If it is felt that the risk of this happening is too high, the doctor will stop your treatment.
Occasionally, a laser burn to your retina may result in new blood vessels growing that may bleed and cause scarring to the central vision resulting in permanent loss of your central vision.
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If laser treatment is given when the changes are at the correct stage, it is very effective.
Laser treatment for early proliferative retinopathy will prevent severe sight loss in over 90% of cases. In most cases it will be able to save your reading and driving vision
Laser treatment for macular changes is not as successful as that for proliferative retinopathy but prevents serious sight loss in 60% to 70% of cases.
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At present laser treatment is the only proven treatment for eye changes caused by diabetes.
Research into new treatments is underway in many centres.
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The benefits of laser treatment greatly outweigh the risks.
It is likely that without this treatment you may lose part of all of your sight.
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In some cases the damage to the very small blood vessels in the retina may already be so far gone that the laser treatment does not work.
The Eye Department may suggest that you have a special intravenous dye test to allow them to assess the circulation in your eyes and whether laser treatment will be appropriate. This test is known as ‘fundus fluorescein angiography'.
If your diabetic eye disease is very aggressive, the changes may be moving on too fast for the laser to control them. It is very important that you make sure that your blood glucose and blood pressure are at the best levels you can achieve, as this can help to slow the process. You should be seeing your general practitioner or diabetes physician regularly to monitor this.
If laser treatment does not work for you, it may be possible for you to have an operation on the eye or regular injections into the eye. You will be referred to a vitreoretinal surgeon to discuss these options if it is felt this might help you.
If you have any questions after reading this information, we suggest that you write them down and discuss them with your eye specialist before you agree to treatment.
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