Sometimes blurred or reduced central vision is more dangerous than it seems.
*Free Basic Eye Screening (in collaboration with Calibre and KPJ-Centre For Sight) **Limited slots**
As we age, the body changes in many different ways, including our eyes. Blood vessels that provide nourishment to the eyes could also turn on it, causing vision difficulties that require immediate attention or pose permanent risk to the vision. This condition is known as age-related macular degeneration or ARMD for short.
WHAT IS ARMD?
Age-related macular degeneration is an ageing process of the retina and choroid. These two layers are involved in light or image processing. The retina and choroid are separated by a strong retinal pigment epithelium (RPE) layer. The RPE is a ‘watertight’ structure that keeps the retinal layer dry at all time. The choroidal layer consists of leaky blood vessels. (see Figure 1)
With ageing, the RPE layer becomes weak and slowly loses its watertight feature. When this happens, blood vessels from the choroidal layer will pass through the RPE and proliferate within the retina. These abnormal vessels within the retina will bleed and distort the retinal layer. (see Figure 1)
WHAT ARE ARMD SYMPTOMS?
ARMD is more common among smokers. The most common symptoms are sudden blurring of vision (mainly in the centre) or sometimes a patient will complain of distortion of the image. (see Figure 2) A detailed eye examination by an eye doctor will reveal the presence of blood under the retina in the effected eye. We can visualise the bleeding in more detail by doing a scan called optical coherence tomography (OCT). This is a non-invasive biomicroscopic test.
OCT will be able to delineate the extent of the disease and used to monitor the response after each treatment.
There are a few treatment options. It can either be an injection into the eye (intravitreal), laser, or surgery. Treatment depends on the severity of the disease as well as the duration of bleeding. If the patient is presented at an early stage, injection of a special drug (anti vegf) is the best treatment. The injection is needed monthly until the disease stabilises. Injection is done under local anaesthesia with very minimal discomfort to the patient. Laser treatment can only be done if the location of the abnormal vessel is far from the centre part of the retina whereas surgery is spared for those who have extensive bleeding.
Early treatment increases the chances of visual recovery. Therefore, the patient needs to seek medical attention early for any new symptoms (within days). Patients will experience recurrent episodes of bleeding and vision will continue to deteriorate, leading to blindness if no treatment is sought. Frequent episodes of bleeding will eventually cause scarring and scarred tissues will not respond to most available treatment. Furthermore, ARMD usually affects both eyes.
In conclusion, ARMD causes blindness among the elderly. Early detection and treatment save vision. Routine yearly eye screening is highly recommended after 50 years old.