Laser glaucoma surgery
There are several methods of glaucoma surgery that involve the use of lasers:
Laser peripheral iridotomy (LPI) uses a YAG or an Argon laser to make a small hole in the iris of the eye, just under the upper eyelid. This allows the pressure between from front and back of the iris to come into equilibrium and it stops the iris bulging outwards. This works well in cases of acute glaucoma; it relieves the pressure within the eye and prevents it recurring. It also makes it less likely that you will develop chronic glaucoma in the future. This form of glaucoma surgery is done with a local anaesthetic and takes about 15 minutes.
Laser trabeculoplasty involves using an Argon laser, either hot or cold, to make a hole in the eye at the base of the cornea. This area functions to allow drainage to the fluid from the aqueous humour to the corneal chamber. By making a hole here, the natural drainage of the eye is enhanced. This type of glaucoma surgery seems to be a good long-term treatment for chronic glaucoma and it can be repeated if the effects wear off over time.
Laser assisted trabeculectomy is a modification of the conventional surgical technique used to treat glaucoma (trabeculectomy – see below). Instead of making a hole in the sclera to relieve eye pressure, a laser is used to trim the thickness of the sclera, allowing fluid to pass through. This has the advantage the eye is left intact – there is no penetration of the eyeball. It therefore has fewer side effects that the conventional form of glaucoma surgery but it does require great surgical skill as the shaving of the sclera is done manually.
Conventional glaucoma surgery
The most common form of conventional glaucoma surgical treatment is the trabeculectomy, done without the use of lasers. Microsurgery is used to cut a flap in the sclera, which does not extend to the full thickness of the tissue. The aim is to create a small window to allow fluid to escape. The area is protected by loosely fixing the flap back in place with some stitches. It does have the disadvantage that the flap is often visible as a bubble in the eye and you can get some scarring around the incision.
More aftercare is needed than after laser glaucoma surgery – antibiotic drops must be used several times a day for several days and you may need strong pain killers to cope with the discomfort that follows the operation. It is vital that you don’t rub your eyes afterwards – which can be very difficult, particularly when you are asleep. Most surgeons insist that you wear eye protectors during the night for quite a few days after this type of glaucoma surgery.