What is Glaucoma?

What is Glaucoma?

Glaucoma is often called “the silent thief of sight” and is the leading cause of irreversible blindness in Singapore. Glaucoma permanently damages the eye nerve, which transmits visual information from the eye to the brain.

In a healthy eye, a clear fluid circulates in the front portion of the eye. To maintain optimal eye pressure, a small amount of this fluid is continuously produced, and continuously flows out of the eye through this area called the angle. In an eye with glaucoma, the fluid does not flow out of the drainage pathway at the angle properly. This increases the pressure inside the eye and damages the eye nerve. There is no single eye pressure number which is normal for everyone. Damage to the eye nerve can happen at different eye pressures for different people.

Types of Glaucoma

There are two main types of glaucoma: open-angle and closed-angle. 

Open-angle glaucoma

In open-angle glaucoma, the fluid inside the eye is able to access the drainage pathway, but the drainage pathway itself is blocked.

Closed-angle glaucoma 

In closed-angle glaucoma, the angle of the eye is very narrow, so the fluid inside the eye cannot enter the drainage pathway easily. 

While closed-angle glaucoma is more common in Asia compared with the west, open-angle glaucoma is still the most common type of glaucoma worldwide.

Symptoms of Glaucoma

In most glaucoma patients, the eye pressure usually rises gradually, hence most people with glaucoma have absolutely no symptoms. They do not notice any problems with their eyes because they have a normal central vision and no pain.

Glaucoma often affects the peripheral vision first, and by the time the central vision is affected and the patient notices that something is wrong, the glaucoma is already very advanced. Hence, glaucoma is often called “the silent thief of sight”.

Rarely, in a few individuals, there is a significant, acute and sudden increase in eye pressure, causing the eye to become painful and red. These symptoms are associated with a sudden and acute increase in eye pressure:

• Eye pain
• Eye redness
• Blur vision
• Haloes around lights
• Headache
• Nausea and vomiting

If you have these symptoms, please see an eye doctor immediately to get urgent treatment!

Risk Factors for Glaucoma 

Glaucoma can affect anyone of any gender, any race, and any age including children. However, the risk of glaucoma rises with:

• Higher eye pressure
• Increasing age
• Family history of glaucoma
• Short-sightedness or myopia
• Poorly controlled diabetes
• Certain medications, e.g. steroids. 

Glaucoma Treatment in Singapore

If you have glaucoma, you should have regular eye examinations as suggested by your doctor. Without treatment, glaucoma will usually result in vision loss and blindness. People with glaucoma require lifelong monitoring and treatment. This involves lowering the eye pressure to a level that would protect your eye nerve from further damage. Your eye doctor would establish a target eye pressure specifically for you. Treatment of glaucoma aims to prevent further vision loss, but will not reverse any eye nerve damage already sustained, and it will not restore your vision or cure your glaucoma. 

With appropriate treatment, the outlook for glaucoma patients is an optimistic one and the majority of treated glaucoma patients will be able to retain good vision during their lifetime.

There are a few main treatment methods for glaucoma in Singapore, including: 

• Glaucoma Medications – such as eyedrops and oral medications, which need to be taken daily. Forgetting to instil the eyedrops will increase the eye pressure and risk further damage to the eye nerve. There may be side effects associated with the eyedrops, such as redness, itchiness or difficulty breathing. 
• Glaucoma Surgery – such as Trabeculectomy, Tube Implant Surgery or Minimally Invasive Glaucoma Surgery.
• Glaucoma Laser Procedures – such as Selective Laser Trabeculoplasty, Laser Iridotomy and Cyclophotocoagulation. 

Glaucoma Screening in Singapore

Early detection and treatment of glaucoma are crucial in preventing further damage to the eye nerve. The American Academy of Ophthalmology recommends that everyone should get their eyes regularly checked from the age of 40. If you have a family history of glaucoma, you should have regular eye exams earlier from the age of 20. Early glaucoma often has no symptoms, so it is important to get your eyes checked regularly.