Glaucoma Treatment

Selective Laser Trabeculoplasty (SLT) may be used for the treatment of open-angle glaucoma in the early stages and ocular hypertension. It may be recommended as an initial treatment, if eye drops are not a suitable treatment for you, or if eye drops alone have not lowered your eye pressure enough to prevent further damage to your sight.

SLT is a quick and painless outpatient clinic procedure in which short pulses of relatively low energy light (laser) are applied to an area towards the front of the eye. This area is called the trabecular meshwork, and is where fluid normally drains out of the eye. The laser treatment alters its biological function in such a way as to produce a long-lasting reduction in the eye pressure. The SLT procedure thus helps to prevent sight loss due to excessively high eye pressure.

In the majority of patients, a Selective Laser Trabeculoplasty will achieve a low IOP about 8 weeks after the procedure is done, though typically patients already using eye drops for glaucoma may still need to continue with their use.  The IOP lowering effects of the laser treatment might wear off in time – about half of all treatments stop working after five years, but the treatment can be repeated.

Laser Peripheral Iridotomy is used for patients who have, or are at significant risk of developing, angle-closure glaucoma.

In a normal, healthy eye, the fluid in the eye (aqueous humour) flows through the pupil into the front of the eye (anterior chamber) and drains away through drainage channels called the trabecular meshwork. Angle-closure glaucoma is due to blockage of these drainage channels, much like a washbasin with something covering the plughole, and is associated with the drainage pathway not being as wide and open as it should be. 

Laser Peripheral Iridotomy is an outpatient clinic procedure in which the ophthalmologist applies a very focused beam of light to form a small hole, not visible to the naked eye, on the outer rim (edge) of the iris, which is the coloured part of the eye. This permanent opening allows aqueous humour to flow into the anterior chamber, the front part of the eye, so that the fluid pushes the iris tissue backwards, thus opening & unblocking the drainage channels.

Trabeculectomy helps preserve sight in people with glaucoma by producing a controlled escape of eye fluid, thus reducing the pressure inside the eye.

The surgeon creates a tiny new opening through the white of the eye (sclera) in an area hidden under the eyelid. This allows the excess fluid inside the eye to drain. The fluid forms a so-called “bleb” which is a small permanent blister-like swelling on the surface of the eye, typically hidden under the eyelid so as it is not usually visible to you. The fluid in the “bleb” is absorbed back into the blood stream, and does not leak onto the surface of the eye.

The eye pressure is closely monitored and can be adjusted gradually by releasing special sutures during the very important postoperative clinic visits.

In the majority of patients, success of the surgery lasts for years (almost 90% were still successful after 20 years in one study), mostly also benefiting from successfully dispensing with the need to use glaucoma medication.

Aqueous shunt implantation is an operation where the eye surgeon places a tiny silicone tube-like device (variously referred to as “glaucoma tube shunts or implants” or “glaucoma drainage devices or implants” or “setons”) in an area towards the back of the eye. When the device is functioning normally, it drains the excess fluid inside the eye, thus reducing the eye pressure.

This type of surgery is usually recommended because eye drops are not a suitable treatment, or they have not lowered the eye pressure enough to prevent further damage to sight, or previous glaucoma surgery was unsuccessful.

For most patients, an aqueous shunt implantation will achieve a low IOP for years (between 70 to 80% were still successful after 5 years in studies), and a sizeable proportion of these do not need to use additional glaucoma medication.