Lasers are machines that amplify light rays to the point where they can be useful for many different applications.
An argon laser can be focused on the retina in order to spot-weld layers of the retina together, or to destroy diseased retina to prevent it from causing any further problems.
Unfortunately, there is a high risk of developing a retinal detachment if you have a retinal tear. By lasering around the retinal tear, we can reduce the risk of the tear progressing to a full retinal detachment. Essentially the laser ‘spot-welds’ the retina to the deeper layers in the eye, preventing it in most cases from detaching.
Diabetic retinopathy is a relatively common eye disease and is the most common cause of blindness in working-age Australians.
In proliferative diabetic retinopathy, abnormal and fragile blood vessels grow on the retina. These have the propensity to bleed easily and cause scar tissue in the retina. The risk of going blind is considerable in such cases. Laser is effective in halving the risk of blindness in some patients with proliferative diabetic retinopathy. Almost always, you will need several sessions of laser in each affected eye.
In diabetic maculopathy, abnormal blood vessels that leak fluid can reduce the vision. Laser can be used in these instances to reduce the leakage. This form of laser is becoming less common due to newer intravitreal therapy being shown to be more effective at improving vision, and less likely to cause long-term retinal scarring.
Up until several years ago, the only effective treatment for retinal vein occlusions was laser. Intravitreal injections now have a larger role in the treatment of vein occlusions, but there are still instances when laser is useful.
In central retinal vein occlusions, it is still beneficial in patients with significant retinal ischaemia. It these cases it reduces the risk of developing a severe form of secondary glaucoma called rubeotic glaucoma.
In branch retinal vein occlusions, laser may still be used when there is significant retinal ischaemia, to prevent the growth of abnormal blood vessels on the retina. It can also be used for macular oedema, if intravitreal injections are not adequately managing the disease.
Generally speaking, retinal laser is safe. It is rare to have any adverse damage from a retinal laser, but as with any medical procedure there are small risks involved.