The Silent Thief of Sight - by Dr. Ho Ching Lin
Often, the disease goes unnoticed until there is a loss of vision. Glaucoma occurs when fluid pressure inside the eye slowly increases and damages the optic nerve, which carries visual information from the eye to the brain. It is sometimes referred to as the Silent Thief of Sight, because it can cause loss in vision and sufferers may have had the disease for years without knowing it.
The disease progresses slowly and painlessly with little or no symptoms. Many people only find out that they have glaucoma during health or eye checks. There are some who may have redness or feel pain in their eyes, or they may suffer from headache and nausea. Others may also have blurred vision or see coloured rings around lights.
Senior consultant Dr Ho Ching Lin, head of Glaucoma Service in the Singapore National Eye Centre said: “Glaucoma is irreversible but medication or surgery can slow down or halt the loss of vision, if it’s treated early. Regular screenings are especially important, especially for those with a family history of the disease.”
Dr Ho – who specialises in childhood and adult glaucoma – added that it is a misconception that only adults suffer from glaucoma. Although uncommon, young people may also be afflicted by it, too. Three out of 10 of her patients are below 35 years old.
In Singapore, about three percent of people over 50 years old have glaucoma and 10 percent over 70 years old. Other risk factors include family history and those who are suffering from medical conditions such as diabetes, high blood pressure, severe short-sightedness or long-sightedness.
Dr Ho said younger patients with glaucoma are more likely to become blind during their lifetime than older patients. “This is because even if the disease progresses at the same rate, a younger patient with the disease starting early in life will have more years to run out of optic nerve fibres compared to older patients afflicted with the disease late in life with fewer more years to live.”
“Acute glaucoma can leave a patient blind in days, while chronic types, without treatment, may take years. While effective treatment cannot reverse any visual loss, it can slow down or halt the progression to blindness. If diagnosed early enough and if appropriate treatment is started and maintained, blindness can be prevented.”
Smart Lens for the Eyes
Singapore National Eye Centre (SNEC) is studying the use of a “smart” contact lens that can measure patients’ eye pressure round the clock, even while they are sleeping. Presently, patients only get their eye pressure measured when they see their doctor.
This “smart” lens which is known as the Triggerfish Sensor was selected by The Straits Times as one of the top 10 local discoveries of 2012.
Senior consultant Professor Aung Tin, Head of Glaucoma Service at SNEC (Research Development) who is in-charge of the study said: “Eye pressure fluctuates over 24 hours. With this “smart” lens we can take patients’ eye pressure at five-minute intervals around-the-clock. This will give us a clearer picture of the patients’ eye condition and therefore enables us to manage them better.
This “smart” lens will be tested on 60 patients here to assess its suitability for Asians. It has already been approved for clinical use in Europe. In the United States, it is pending approval from the US Food and Drug Administration. Here in Singapore, it has not been cleared for use except for investigative research.
Prof Aung Tin is a clinician-scientist and his research interests are angle closure glaucoma and the molecular genetics of eye diseases. He is instrumental in establishing a world-leading research programme in SNEC focusing on ophthalmic genetics.
Dr. Ho Ching Lin is Head of Glaucoma Service (Clinical) & Senior Consultant, Singapore National Eye Centre. Reprinted with permission from the Singapore National Eye Centre, www.snec.com.sg.
All rights reserved. Check your family history
Glaucoma has a strong genetic link. If someone in your family has or had glaucoma, it increases your chances of being afflicted by it, too.
First-degree relatives (parents, siblings and children) of glaucoma patients have a higher risk of the disease.
If you have a sibling with glaucoma, you will have a three to five times higher risk for glaucoma.
If you have a parent with glaucoma, you will have a two to three times higher risk.
If you have a family history of glaucoma, it is advisable that you should be examined by an ophthalmologist especially if you are over 40 years old. Thereafter, even if the assessment is normal, you should continue to go for regular check-ups with the ophthalmologist every two or three years until the age of 50. After that, you should have your eyes checked yearly.