Glaucoma surgery 09/09/2013

Surgery is normally recommended for glaucoma when medical therapy is inappropriate, badly tolerated, not very effective or defectively applied by a specific patient and the glaucoma has not been brought under control, with tests showing that the damage is progressing or when there is a very high risk that it will get worse. The goal of surgery is to enhance the filtration and drainage of the aqueous humour.

At the Institut de la Màcula, we choose the most suitable technique depending on the patient's characteristics and the extent and progress of the glaucoma.

Trabeculectomy

Trabeculectomy is protected partial thickness filtration surgery that consists of making an outlet for the aqueous humour from the anterior chamber of the eye to the subconjunctival space, creating a subconjunctival filter bleb.

It is indicated to reduce intraocular pressure when treatment with hypotension drugs is not enough and the illness is advancing.

Its success often depends on the right post-operative care to ensure the fistula functions correctly. The goal of this operation is for the epithelial and conjunctival wounds to heal up completely while the scleral wound only heals partially.

Non-penetrating deep sclerectomy

Non-penetrating operations for glaucoma were originally described at the beginning of the 1970s. Their goal was to reduce intraocular pressure and thereby avoid some of the complications of a standard trabeculectomy.

Non-penetrating deep sclerectomy is drainage surgery to reduce intraocular pressure. It consists of helping the aqueous humour to flow from the anterior chamber of the eye into the subconjunctival space without perforating the anterior chamber.

A superficial scleral flap is made as well as a deep scleral dissection underneath, leaving only a fine layer of the sclera and Descemet's membrane. This is essential to ensure that the iris-cornea angle is open. Intraocular pressure is reduced in a more physiological way.

This is effective, less invasive surgery but is technically difficult.

Implant of aqueous humour drainage devices or valves

This glaucoma surgery consists of inserting a device or valve that connects the intraocular space, via a tube, to the subconjunctival space, with a reservoir or plate.

Different types of devices have been developed to improve filtration and help the aqueous humour to flow into the subconjunctival space on the eyeball equator.

The drainage valves or devices currently used for glaucoma usually consist of a tube placed in the anterior chamber, the ciliary sulcus or via the vitreous cavity if the patient has undergone a vitrectomy. The aqueous humour flows through this device to an extraocular reservoir, placed on the eyeball equator on the sclera.

These devices are usually reserved for complicated cases of glaucoma in which conventional filtration surgery has failed or is likely to fail, or in cases where this cannot be carried out because the state of the conjunctiva or angle advises against it.