What is the treatment for glaucoma ?
There is no final cure for glaucoma
Once you have been diagnosed with glaucoma you should be under constant supervision of an ophthalmologist for the rest of your life. Pressure lowering is the weapon to stabilize the disease or to slow further progression. Cure or repair of existing damage is not an option. Hence the importance of early detection and diagnosis!
The ophthalmologist has a broad range of treatment modalities to lower intra-ocular pressure:
- Different types of pressure lowering eye drops
- Pressure lowering pills
- Laser treatments
- Surgical procedures
The vast majority of glaucoma patients will be put on drops initially and many of them will never need anything else. Laser treatment may be the initial treatment in suitable patients as an alternative for drops. Or it may be used as an adjunctive therapy if drops alone fail to lower the pressure to the pre-set target value. Pressure lowering pills (acetazolamide) are very effective but their general side effects preclude long term use. They are typically used in secondary glaucoma to control transient pressure spikes. A minority of patients will need surgery either because the drops fail to lower the pressure to the desired level, or because they are not tolerated, or because the patient does not use the drops in a proper way.
So it is quite possible that you start initially with drops but that in the course of the disease you need additional or alternative therapeutic modalities to keep the pressure low in order to prevent further damage and the evolution towards low vision/blindness.
There are many different types of pressure lowering drops. Your ophthalmologist will decide which drop is best for you taking into account many variables related both to your eye condition and to your general health. Since all pressure lowering drops are short acting, daily instillation is required, each and every day, in order to prevent pressure spikes. One strategy not to forget your daily drops is to instil them every day at the same time point and to link the instillation to a daily routine such as meals or teeth brushing etc. If you have to instil two different types of eye drops at the same time point, wait at least five minutes in between. Most eye drops must be discarded one month after opening the bottle.
Most eye drops contain not only the active substance but also a preservative. Chronic exposure of the eye to this preservative may induce chronic irritation and cause dry eye syndrome, a common complaint in glaucoma patients. Since most glaucoma patients have to use their drops for many years, preservative-free drops_ now widely available_ are the best choice.
How to instil eyedrops?
Tilt your head backward and pull the lower eyelid down to create a small gap between the eyeball and the lid. Keep the nozzle of the bottle about one centimetre above the eye and gently squeeze it until one drop falls into the gap. If you are not sure whether the drop really got in your eye, give it a second try. Never touch the surface of the eye with the nozzle of the bottle! Close your eye for one minute and press with your finger on the inner corner of the eye. This manoeuvre will close the tear duct and prevent the drop from flowing off into the nose; now the drug has ample time to penetrate into the eye.
Laser therapy (laser trabeculoplasty or LTP)
This laser treatment is a painless, ambulatory procedure. After instillation of anaesthetic drops the ophthalmologist puts a special lens (a gonioscopy lens) on the eye to visualize the drainage structures of the anterior chamber angle ( = trabecular meshwork). Small impacts with the laser at the level of the trabecular meshwork temporarily improve its function resulting in better outflow of intraocular fluid and pressure lowering. Laser therapy is effective in 80% to 85% of treated eyes, but the effect wears off over time.
Surgery is the next step when drops and laser treatment fail to keep the pressure sufficiently low. The general principle of glaucoma surgery is to create a small opening in the eye wall to allow escape of intraocular fluid in a controlled way; the excess fluid accumulates in the tissues around the eye. A surgical procedure may lower the pressure for many years, sometimes for the rest of your life. If the pressure after a surgical procedure is still too high or if it goes up again over time, pressure lowering drops may be added or a second intervention may be considered, eventually using a different technique such as the implantation of a little valve in synthetic material. Glaucoma surgery is successful in lowering the pressure in about 80% of cases, but complications can occur as in any surgical procedure. Haemorrhages, cataract formation, loss of vision, and infection are all potential complications. A conjunctival haemorrhage is common but harmless and resolves in a matter of weeks. Haemorrhages in the inner eye, much more serious, are fortunately rare. It is well known that glaucoma surgery accelerates cataract formation, but modern cataract surgery deals with this issue in a safe and effective way. Decreased vision is a common complaint especially in the immediate postoperative period but in most instances vision returns to preoperative levels after a few weeks, although a slight loss may be permanent. Infection of the eye, a serious complication, is very uncommon after glaucoma surgery.