Laser: for diabetic retinopathy and retinal vein occlusions
Laser is a very bright light that is used in the treatment of eye disorders. The word laser means Light Amplification by the Stimulated Emission of Radiation. The laser we use for eye disorders affecting the blood vessels at the back of the eye is green and is called an argon laser.
There are two main reasons that you may need laser treatment.
- New blood vessels
New blood vessels grow at the back of the eye and these new blood vessels are abnormal blood vessels. New blood vessels can beel causing haemroohages in theeye, reducing your sight. Early treatment reduces the risk of bleeding and helps to keep the sight. Laser treatment causes the new blood vessels to disappear.
Oedema is the medical word for waterlogging or oedema in the retina, like a filling a sponge. may collect at the back of the eye. Oedema collects when the blood vessels at the back of the eye leak, rather like a river bursting its banks. Oedema damages the delicate structures at the back of the eye. Laser treatment dries up the oedema.
Diabetes, blockage of a vein or an artery at the back of the eye are the commonest conditions which need laser.
It is not possible for you to know whether or not you need laser. If you have diabetes, you must have a regular eye examination to ensure that any problems can be treated early and effectively. Regular eye examinations can detect the new blood vessels and oedema.
Laser is performed under local anaesthetic as an outpatient procedure. Drops are placed in your eye to dilate the pupils. The drops can take between 20-45 minutes to dilate your pupils fully. You will notice that your vision is blurred because the pupils are dilated. Anaesthetic drops are placed in your eye. You are then ready for your treatment .
Laser is delivered using a slit lamp or microscope. There is a box like apparatus beside the slit lamp which creates the laser energy. You may notice a dull noise during the procedure. This is an internal fan which cools the laser
A contact lens is placed on your eye and you sit at a 'slit' lamp. You will notice that there is a very bright light and a smaller red light. The bright light allows the doctor to see the internal structures of your eye and the red light is used for focusing. The doctor holds the contact lens and presses a foot pedal to activate the laser. You will probably feel each laser pulse. You may hear a click with each laser pulse.
Laser treatment takes between a few minute - 20 minutes. The time depends on how much laser and what type of laser you need.
Your vision will be very blurred following the laser treatment. This can last several hours. Your vision is blurred due to a combination of the dilating drops and the bright light of the slit lamp and the laser. As the effect of the drops wears off your sight becomes clearer.
The sight is poor from all the glare for 15 minutes.
If you have laser for new blood vessels, you will probably need laser treatment on several occasions. You will be assessed 1-2 months following the treatment. If the new blood vessels have not disappeared, you may require additional treatment. New blood vessels may take two to three years or even longer to disappear. During this time you may require further laser treatment and follow up on several occasions.
If you have laser treatment for oedema, you will be seen three to four months following the treatment. If the oedema has not completely dried up, you may require more treatment.
There are potential complications following all forms of laser. Very rare complications include infection. Sometimes a scratch develops on the surface of the eye, and sometimes inflammation develops. Complications are uncommon and usually settle with time.
If you have laser treatment for oedema at the back of the eye, you may notice a black spot following the treatment. The black spot is often close to the centre of your vision. This is due to the effect of the laser. It fades with time but may be permanent. If you have a lot of laser, you may notice that your night vision fades a little.
Your sight will nearly normal the next day. If you have severe retinopathy, then your sight may not be quite as good (but the laser will help to stabilise the retinopathy in the very long term).
If you have had several sessions of laser treatment, it is possible that you may no longer fulfill the legal requirements for driving. You need to have a special test, called a visual field test to determine if you fulfill the legal requirements for driving. You need to inform the DVLA that you have been treated for an eye problem. They will contact the hospital for a report and the DVLA will inform you directly of their assessment of your suitability for driving.
After a lot of laser many people with diabetes find they cannot drive at night. Car headlights start to cause a lot of glare. Unless you have needed an awful lot of laser and your retinopathy has been very troublesome you normally have good enough sight to drive during the day, although perhaps not for long journeys.
You will require follow up after your laser treatment. Your follow up appointment will be arranged at the time that your laser treatment is booked. Sometimes you require more laser treatment.