Glaucoma

The probability of glaucoma increases with age.
People with an increased eye pressure have a higher risk as to the presence of chronic open angle glaucoma.
If any other family members suffer from this condition, then you have a higher risk of getting it.
Patients of African origin also have an increased risk of developing chronic open angle glaucoma.
People who have had any form of eye trauma, also have an increased risk, as well as diabetics and people with myopia.

When we perform a clinical examination in glaucoma patients, we measure the pressure, we examine the eye drainage system, we look at the lens, and we evaluate the optic nerve, to see if there is any damage present already. Afterwards, visual activity is tested.

A normal optic nerve is composed of more than 1 million tiny nerve fibres. With chronic open-angle glaucoma many of these nerve fibres are gradually lost, causing the appearance of the optic nerve to gradually change. In medical terms this is called cupping. When cupping increases, blind spots develop in the visual field.

Ophthalmologists use a technique called visual-field examination. This study serves to discretely detect the onset of blind spots in someone’s visual field. Due to this examination, we are able to find out whether and where any blind may occur. You may not even be aware of these blind spots.

At the onset of the condition of chronic open angle glaucoma, your vision is completely normal. If further damage occurs to your optic nerve, then, gradually you will develop blind spots. These blind spots typically remain undetected during your daily activities, until the moment that the centre of the visual field is affected. When all the optic nerve fibres die, blindness occurs. Although no real cure for glaucoma exists, we try to avoid further damage to the optic nerve by lowering the pressure in the eye. This usually allows us to stop the process and prevent further damage to the optic nerve. A recent study, of the “Ocular Hypertension Study” showed that people with elevated eye pressure but no existing chronic open angle glaucoma, will often profit if treated early for this.

This is why it is incredibly important that you visit you ophthalmologist regularly from a certain age onwards, especially if you show a higher risk than others of developing chronic open angle glaucoma. Once glaucoma is diagnosed, the treatment is really a team effort between you and your ophthalmologist.

The most commonly used method to treat glaucoma is the use of eye drops. These drops lower the eye pressure in 1 or 2 ways: either by reducing the production of aqueous humour or by increasing the drainage of the aqueous humour. When eye drops for the treatment of chronic open angle glaucoma are prescribed, it is very important to be very precise in the use of these drops and follow up the prescription to the word. After you’ve instilled the eye drops, it may be advisable to keep your eyes shut for half a minute or so. You may also apply a little pressure on the tear duct with your index finger, to avoid unwanted overall side effects, such as, a decrease in heart rate or the onset of fatigue.

Like all systemic medications glaucoma drops may also have side effects. We refer for instance to the occurrence of red eye, or a slight change in colour of the iris. Side effects may also occur in other parts of the body, such as changes in heart rhythm and the level of breathing. Your ophthalmologist will try to choose the most appropriate treatment for you. Therefore it is of utmost importance that your eye doctor is informed about your general medical condition and any medications you may currently be taking. It is therefore a good idea to bring with you a small list of the medications you take whenever you come in for an eye examination. It’s also a good idea to notify your GP/doctor that you take glaucoma medication.

In some cases, laser surgery can be used to further reduce the eye pressure. With laser surgery we can increase the drainage of the aqueous humour from the eye. This type of laser surgery is called laser trabeculoplasty (LTP).

For people with a closed angle glaucoma laser, iridotomy is more recommended. The laser creates a small hole in the iris which makes the drainage of aqueous humour through this hole into the trabeculum easier.

If eye drops or laser surgery is still insufficiently effective to lower the eye pressure, a surgical solution is then considered. The name of this surgery is trabeculectomy. The purpose of this procedure is to create a new filtering system in the eye, making it easier for aqueous humour to escape from the eye through new passages. The ultimate result being that the intraocular pressure will continue to drop. The aqueous humour is drained through a new filtering system, which we call a Bleb. A Bleb is usually hidden under the upper eyelid. A Bleb is created to increase the drainage of aqueous humour, in order for the eye pressure to eventually decrease. Glaucoma Surgery is also typically an outpatient procedure, i.e. you need not stay overnight in a hospital. Serious complications of such surgery are rare. Of course as with any surgery, there is always still a small risk factor, for example the occurrence of postoperative bleeding or infection. It could therefore still be necessary after the surgery to continue the use of glaucoma medication, or to undergo additional surgery. The final result of the procedure depends on how well you heal, and the healing process is obviously different for each patient.