Glaucoma is a group of eye diseases involving damage to the optic nerve. The optic nerve is responsible for carrying neural signals from the eye to the brain to the perception of vision. Optic nerve damage causes you to permanently lose vision, particularly your peripheral vision.
There is currently no cure for glaucoma. However, there are numerous effective treatment options available. Educating yourself on the symptoms of glaucoma and understanding your risk factors can assist with early detection of glaucoma, giving you the best chance to prevent vision loss.
What Causes Glaucoma?
It’s not yet fully understood what causes glaucoma. However, we do know that eye pressure – intraocular pressure – plays a part in damage to the optic nerve and the progression of vision loss.
Types of Glaucoma
There are many different ways of classifying the types of glaucoma. A broad way of categorising people with glaucoma is by the state of the aqueous fluid drainage channels of the eye, known as the angle.
Angle Closure Glaucoma
Closed-angle glaucoma means that the space between the coloured iris and the transparent cornea is very narrow or entirely closed in sections. This affects aqueous fluid drainage from the eye, which results in a very high spike in eye pressure. This elevated fluid pressure causes optic nerve damage.
Acute angle closure glaucoma is a medical emergency and needs immediate treatment to save the optic nerve.
Symptoms of angle-closure glaucoma include:
- Severe eye pain
- Blurred vision
- Nausea and vomiting
- Haloes around lights
- Eye redness
Open Angle Glaucoma
As the name suggests, open-angle glaucoma occurs when the angle between the iris and cornea is wide enough to allow unimpeded fluid drainage, yet the eye pressure continues to increase. This could be from another blockage of the angle from debris or inflammation. However, eye doctors are unclear as to the exact underlying reasons for this. Primary open-angle glaucoma is the most common form of glaucoma.
It’s important to note that even though high eye pressure is typically considered the reason for optic nerve damage, developing glaucoma is also possible in the presence of normal eye pressure. People with glaucoma and normal eye pressure are considered to have a condition called low tension or normal tension glaucoma.
Unlike acute angle closure glaucoma, primary open angle glaucoma does not tend to present with any symptoms in the early to even moderate stages. Only when there has been a significant loss of your peripheral vision are you likely to realise something is not quite right.
Because of the lack of symptoms of glaucoma in the majority of cases, it’s important to attend regular eye exams with your optometrist or eye doctor. This allows early detection and enables prompt treatment to reduce the risk of permanent vision loss.
Glaucoma Risk Factors
Though everyone should have regular eye exams, if you have one or more risk factors for glaucoma, your eye doctor or optometrist may recommend a more frequent review schedule for a comprehensive dilated eye exam. A dilated eye exam involves instilling eye drops to widen the pupil so your eye care professional can get a good look at the optic nerve.
Conditions or circumstances that put you at a higher risk of developing glaucoma include:
- A family history of glaucoma
- Older age
- Certain medical conditions such as migraines, sleep apnoea, diabetes, or hypertension
- Short- or long-sightedness
Even if you don’t have any factors that put you at a higher risk, it is still possible to develop any of the types of glaucoma, so regular eye exams are important. It may not be possible to prevent glaucoma, but it is possible to catch glaucoma early to enable prompt treatment.
Though there is no cure for glaucoma, treatment for glaucoma is usually effective at halting vision loss.
All methods of treatment for glaucoma are based on lowering intraocular pressure, thereby protecting the optic nerve and providing disease control. Your eye doctor will recommend treatment options to you after considering various factors, in particular, how well the therapy is likely to lower your eye pressure.
Medications and Eye Drops
Prescription eye drops are often the first-line treatment for glaucoma. These eye drops are designed to reduce eye pressure by either decreasing fluid production or increasing fluid drainage. It is not uncommon to need more than one type of eye drops, which often need to be instilled up to three times a day. These prescription eye drops will need to be used long-term to avoid vision loss.
In cases of acute angle closure glaucoma, your eye doctor may prescribe an intravenous or oral medicine to rapidly and safely reduce the eye pressure. However, this is not typically a long-term therapy.
Laser treatment for glaucoma can be a good alternative to eye drops in people with open-angle glaucoma who are unable to use drops long-term due to side effects or other concerns. These laser treatments aim to reduce fluid pressure by improving drainage through the angle.
In closed-angle glaucoma, or for those at risk of it, the eye doctor will perform a laser treatment known as a laser peripheral iridotomy. This involves using a laser to create another channel for excess fluid to drain.
Glaucoma surgery has advanced since traditional surgery techniques. Many eye doctors now use minimally invasive glaucoma surgery, a group of surgical techniques that involves surgical insertion or shunts, tubes, or other microscopic devices into the eye to manage eye pressure and prevent vision loss.
If you have cataracts, many of these surgical procedures can be combined with cataract surgery.
Coping and Support
Living with glaucoma and permanent blind spots can be debilitating. There are many support groups you can access, as well as low-vision services that can complement your glaucoma treatment.
Consider looking into resources such as the Glaucoma Research Foundation or Glaucoma Australia for more information about glaucoma and how you can find more support.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.