Laser trabeculoplasty involves the use of a highly focused beam of light to treat the drainage area of the eye and to make it easier for the fluid to flow out of the eye. This leads to a lower eye pressure and helps to preserve the functioning of the optic nerve. This treatment is used if glaucoma gets worse despite using eye drops, or if there are problems tolerating eye drops. This treatment lowers the pressure inside the eye in about 75% of cases. However, this improvement often decreases with time and it is usually necessary to continue using drops to help to control the eye pressure after the laser treatment. This treatment may be tried before glaucoma drainage surgery (trabeculectomy) is recommended but not in cases where the eye pressure is excessively high.
There are two types of laser trabeculoplasty: Argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). Both types of treatment are performed in a similar way, using a special contact lens placed on the eye to direct the laser light at the drainage area or ‘angle’ at the very front of the eye. The treatment in carried out in the clinic using anaesthetic drops, with patients describing a mild ‘heat sensation’ during the treatment. After the laser treatment the pressure inside the eye needs to be measured. The two types of treatment are similar, but with SLT a lower energy laser is used to open the drainage angle of the eye and because of this it can be repeated whereas ALT is often used just once.
Serious complications from laser trabeculoplasty are rare, with the most common being a rise in pressure within a few hours of the treatment. This complication is prevented by using some pressure lowering eye drops at the end of the procedure. Other complications include: inflammation inside the eye after treatment, temporary cloudiness of the cornea and discomfort.