“I can't have glaucoma — I can still see clearly.” As an ophthalmologist with over 17 years of experience, I have encountered many glaucoma patients who do not have any symptoms, especially in the early stages of their condition.
More than 90% of patients with glaucoma remain undiagnosed worldwide; detection is tremendously crucial, especially in the early stages – because once there is eye nerve damage, the loss in vision is irreversible.
Glaucoma is a leading cause of blindness globally, and is often poorly managed in developing nations:
While this widespread disease cannot yet be cured, glaucoma treatment in Singapore is of paramount importance to prevent further irreversible visual loss.
If you’re living with glaucoma in Singapore, read on to find out more about this blinding condition and the available options for glaucoma treatment.
Glaucoma is a disease that damages your eye nerve. The condition usually occurs when fluid (aqueous humour) builds up in your eye, therefore increasing the pressure in your eye, and eventually damaging the eye nerve.
Our eyes naturally create fluid that provides oxygen and nourishment to the rest of the eye. In a normal eye, as new fluid is produced within our eyes, the same amount of fluid drains out via our drainage angles. This process keeps the intraocular pressure (IOP) or eye pressure stable.
However, in eyes with glaucoma, the drainage angles do not drain fluid adequately, causing fluid to accumulate within the eye, increasing eye pressure and eventually damaging the eye nerve.
If left untreated, glaucoma can eventually lead to permanent blindness. As early glaucoma does not have any symptoms, it is often not detected until it’s too late, when damage to the eye nerve is severe. Hence, glaucoma is often called “The Silent Thief of Sight”.
Glaucoma can be a primary (not associated with other eye diseases) or secondary (associated with other eye diseases) condition.
It can be further categorised under open-angle (the drainage angles are open and fluid can easily enter the drainage pathway) and closed-angle glaucoma (the drainage angle is closed because the iris is contact with the cornea, hence preventing fluid from entering the drainage pathway).
|Type of glaucoma||What it is|
|Primary open-angle glaucoma||This is the most common form of glaucoma worldwide. The drainage angle is open and fluid can easily enter the drainage pathway. However, the drainage pathway itself is not functioning well, hence reducing drainage of fluid from the eye.|
|Primary angle-closure glaucoma, or narrow-angle glaucoma||This occurs when the drainage angle is closed because of contact between the iris and the cornea. Hence, fluid is unable to enter the drainage pathway, resulting in increased eye pressure. In eyes with acute angle-closure, the drainage angles are completely closed, resulting in markedly raised eye pressure. This is a medical emergency which can cause rapid blindness and requires immediate treatment.|
|Normal-tension glaucoma, or low-tension glaucoma||This occurs when the eye nerve becomes damaged at normal levels of eye pressure. Normal tension glaucoma is associated with diseases such as high blood pressure, diabetes and sleep apnoea.|
|Secondary glaucoma||This occurs because an associated condition has resulted in increased eye pressure and damage to the eye nerve. Eye trauma, inflammation, medication use, and poorly controlled diabetes can cause secondary glaucoma. Traumatic glaucoma can occur immediately, or even years after an injury.|
|Pigmentary glaucoma||This is a type of open-angle glaucoma that occurs when small pigment granules on the iris are chafed off and become trapped in the eye’s drainage pathway.|
|Exfoliative glaucoma||This occurs when a white, flaky, dandruff-like material occludes the drainage pathway of the eye, increasing eye pressure.|
|Neovascular glaucoma||This condition arises when abnormal new blood vessels develop on the iris and over the drainage angles. These vessels damage the drainage pathway, preventing fluid from flowing out of the eye. Poorly controlled diabetes can result in neovascular glaucoma .|
|Uveitic Glaucoma||Inflammation within the eye damages and obstructs the drainage pathway in the eye, hence resulting in raised eye pressure. Steroid used to treat the eye inflammation can also obstruct the drainage pathway, further elevating eye pressure.|
|Congenital Glaucoma||This is a rare and often hereditary condition caused by the abnormal development of the drainage pathway in a child.|
Early glaucoma (open-angle glaucoma and chronic angle-closure glaucoma) often has no symptoms. Visual impairment might not be noticeable until the glaucoma is advanced.
As the increase in eye pressure and the visual loss is gradual in most patients, it typically and initially presents as loss of peripheral vision. As the glaucoma progresses, one’s vision becomes increasing constricted, until the patient is eventually left with only a tiny central island of vision.
At this stage, the patient will only be able to see what is directly ahead of him/her.
In a minority of patients, the eye pressure increases suddenly to very high levels, resulting in acute glaucoma. This is often associated with closed angle glaucoma.
Open-angle glaucoma cannot be prevented. Closed-angle glaucoma, on the other hand, is preventable. In the early stages of the disease, a laser procedure called an iridotomy can potentially help to widen the drainage angles and prevent an increase in eye pressure.
Early cataract surgery can also widen the drainage angles and has been shown in a large study to be more effective in lowering the eye pressure and improving the vision compared with iridotomy.
In Singapore, glaucoma affects about 3% of those 40 and older, and nearly 10% of those aged 70 and above. It is reported that while everyone has a 2.3% lifetime risk of glaucoma, first-degree relatives of glaucoma patients have a ten-fold increase in risk.
Here are the other risk factors for glaucoma:
Damage to the eye nerve in eyes with glaucoma cannot be reversed, so if you have risk factors for glaucoma, it is important to have annual eye examinations. Even if you do not have any of the above risk factors, it is recommended to have regular eye examinations after the age of 40.
In addition, to keep your eyes healthy, I encourage the following:
If you have both cataracts and glaucoma, you can opt for combined cataract and glaucoma surgery which will not only improve your quality of life but will also reduce or eliminate your need for glaucoma medications.
Some ophthalmologists undergo further subspecialty training (fellowships) to become glaucoma specialists. Early glaucoma may be difficult to diagnose, and a review by a Singaporean glaucoma specialist may be necessary for a definitive diagnosis of glaucoma to be made, and for the type of glaucoma to be identified.
If you have risk factors for glaucoma or if you experience symptoms of acute glaucoma listed above, please visit your ophthalmologist immediately, as early glaucoma treatment is crucial in Singapore.
When it comes to glaucoma screenings in Singapore, you can expect to undergo the following:
Glaucoma surgeons in Singapore are likely to employ various methods to diagnose glaucoma.
Glaucoma treatment in Singapore often starts with prescription eye drops.
Eye drops work by reducing the production of aqueous fluid, or by increasing fluid drainage. The use of daily eye drops is usually life-long, and compliance is crucial. Some patients may require several types of glaucoma eye drops in order to lower their eye pressure to an acceptable level.
If glaucoma eye drops are not able to reduce the eye pressure sufficiently, if the patient is not compliant with the eye drop regime or if there are significant side effects from the eye drops, other treatment options for glaucoma in Singapore are:
It is important to tell your eye doctor if you have the following conditions or drug allergies, as it will affect the type of treatment you are suitable for:
Do note that glaucoma eye drops might have side effects, which may affect some patients more than others. It is important to inform your eye doctor if you are experiencing any side effects from glaucoma eyedrops and please follow your eye doctor’s instructions when administering these eye drops.
Yes, part of the costs for surgery and laser procedures are Medisave-claimable depending on your condition. Please speak to our friendly staff for more information.
If you suspect that you might have glaucoma, there is no time to waste – see a glaucoma specialist as soon as possible. Early treatment of glaucoma can preserve vision.
Do you have any questions for me? Feel free to drop me a message.