Glaucoma is a progressive disease that affects the optic nerve of the eye. The optic nerve is part of the central nervous system (CNS) and is the ‘cable’ that connects the eye to the brain. Once it is damaged, it cannot regenerate (repair itself). As nerve fibers of the optic nerve die slowly due to glaucoma, peripheral vision is also lost gradually. People with advanced glaucoma may experience “tunnel vision”, in which they can only see objects in the center of their visual field. The image below is an illustration of vision of a person with glaucoma.

What makes glaucoma more dangerous is that the most common type of glaucoma does not show any obvious symptoms, hence goes undetected in many people. Thus, glaucoma is known as the “silent thief of sight”.

Glaucoma is one of the leading causes of irreversible blindness and therefore it is important to know the risk factors that can lead to this disease.

Strong risk factors for Glaucoma are:

1. Advancing age (over 60 years old)
2. Certain races are more predisposed than others (Blacks/ Hispanics/ Asians )
3. Family history (1st degree relatives)
4. High baseline Intraocular pressure (IOP)
5. Suspicious optic nerve appearance / asymmetry

Possible risk factors are:

1. Myopia (Near sightedness)
2. Vascular disorders – Diabetes/ Hypertension/ hypercholesterolemia)
3. Previous eye injury/ eye surgery

Other risk factors are:

1. Long term use of steroids (eye drops/ creams/ oral/ inhalers/any other form)
2. Migraine headaches (vasospasms)
3. Sleep related breathing disorder (sleep apnea)
4. Hypotension (low blood pressure)

One should have regular eye examinations as early detection is key to preventing further vision loss from glaucoma. According to guidelines by American Association of Ophthalmology (AAO), adults who have no signs or risk factors for eye disease should have a comprehensive eye examination at age 40 if they have not received one. For asymptomatic individuals without risk factors who are 40 to 54 years old, and have had a comprehensive eye examination, the recommended interval is once every 2-4 years. For those aged between 55 and 64, they should get an eye examination every 1-3 years. Anyone aged 65 or older should have an eye examination every 1-2 years, despite not having any symptoms.

By consulting a glaucoma specialist, the doctor is able to examine your eyes and determine if you have glaucoma. With the help of equipment such as the applanation tonometer, optical coherence tomography (OCT), visual field analyser, and fundus camera, the doctor is able to detect subtle changes in your optic nerve and retina.

Screening of higher-risk groups may be the most cost-effective method of reducing the volume of undiagnosed glaucoma and patient history appears to be a practical means of screening to identify the higher risk individuals.

There is a risk that if glaucoma is not detected early, irreversible loss of vision may occur, and that would affect the quality of life. Residents within Klang Valley in areas such as Cheras, Puchong, Shah Alam, and Kepong can come visit our glaucoma specialist, Datin Dr Thayanithi to have their eyes examined.

Does someone you know have glaucoma? It is the leading cause of irreversible blindness in the world. It affects the optic nerve, the nerve that carries visual information from your eye to your brain so that you can see. It is also a multifactorial and complex disease with specific characteristics of optic nerve damage and visual field loss.

Glaucoma and Intraocular Pressure (IOP)

Intraocular pressure is the only modifiable risk factor for this disease. Intraocular pressure (IOP) is measured with a tonometer during an eye examination. A normal intraocular pressure (IOP) is between 10-21mmHg. Although high intraocular pressure has been established as the strongest risk factor, there is no specific level of elevated eye pressure that definitely leads to glaucoma. On the contrary, there is no lower level of IOP that will absolutely eliminate a person’s risk of developing this disease. However, for specific individuals vision loss can occur when the intraocular pressure (IOP) is high (James Tsai, Glaucoma Research Foundation 2017). A person with elevated intraocular pressure is referred to as a ‘glaucoma suspect’. The term ‘glaucoma suspect’ is also used to define those patients with other risk factors such as positive family history of glaucoma or history of steroid use. Clinical risk factors include an asymmetry or cupping of the optic disc, having thin corneas with a central corneal thickness of less than 555 microns and high myopia or short-sightedness.

Early Detection

There are two types of glaucoma which are open-angle or angle-closure. Angle-closure glaucoma is more common among Asians. Patients with acute angle-closure will present to the clinic with painful red eyes, headache and periocular pain. This is also accompanied with nausea, vomiting and sudden blurring of vision. Acute-angle closure is a serious and often sudden condition that would require urgent referral to an Ophthalmologist. In open-angle glaucoma, damage to the vision tends to progress slowly over years and can ‘sneak up’ on an individual before they realize their vision is no longer normal. If you are above the age of 55, it is a good idea to see an eye doctor regularly so that it can be detected and treated early.