Macular degeneration is a age-related condition of the retina. The Vitreo-Retinal Service at Singapore National Eye Centre (SNEC) discusses some important facts.
Be aware of early signs of age-related macular degeneration, which include distorted vision or a patch in the middle of one’s vision. Early diagnosis of AMD and treatment is associated with better outcomes for patients, ultimately reducing the risk of blindness.
Many older people may not know that they have age-related macular degeneration (AMD), which, if not treated in time, can lead to blindness. They may overlook small changes in vision, wrongly attributing them to other causes such as ageing. By the time their vision is distorted enough to bother them, it may be too late.
If they get to a doctor early enough, some types of AMD can be treated effectively. In its early stages, tiny yellow spots known as drusen may appear underneath a patient’s retina, which can be detected by an opthalmologist with an eye examination.
“Although the drusen are early signs of AMD, most cases the patients retain good vision and only a small number progress over many years to the serious sight threatening forms of AMD," said
Clinical Associate Professor Anna Tan, Consultant,
Medical Retina Department,
Singapore National Eye Centre (SNEC), a member of the
Some warning signs to look out for that may signify that AMD has worsened include increased distortion where a straight line may suddenly appear wavy, or some words may go missing, especially if they are in the central vision (the focal point).
These mild symptoms usually initially affect only one eye hence may go unnoticed unless the individual happens to test each eye separately. As the condition advances,
the visual symptoms become more obvious and, eventually, affecting the central vision. The peripheral vision (vision on the sides away from the center) may be preserved, however the patient may experience blurring of the central vision and often difficulty reading in dim lighting environments.
An ageing disease
Typically affecting those above 50 years old, AMD is a result of the progressive ageing of cells in the retina, which is the thin sheet of “photographic” tissue that lines the back inside wall of the eye,
capturing images and sending these images to the brain (the camera of the eye).
There are two forms of AMD: dry AMD and wet / neovascular AMD. In the dry form, damage to the retina occurs gradually and patients have gradually worsening central vision. The wet form of AMD however, is associated with a more rapid loss of vision and in severe cases can present with a black patch in the central vision.
AMD is a chronic condition and requires long-term follow up. For dry AMD, there are no treatments available, but as many patients experience gradual vision loss they may learn adaptive habits to cope with their daily activities. Retinal supplement tablets may be able to reduce the risk of progression of AMD in some individuals with higher risk.
There is dry and wet AMD. The dry form is more common. Damage to the retina occurs gradually and patients see less central vision with each passing year.
For wet / neovascular AMD, vision loss occurs more rapidly, due to abnormal blood vessels growing underneath the retina that leak or bleed.
Treatment for this form of AMD is primarily with long-term injections of medicine in the eye and occasionally the addition of laser therapy.
"By adhering to long-term treatment and follow-up most patients are able to experience an improvement in vision that can be maintained. However, in certain cases when the AMD is detected late or patients do not adhere to treatment and follow-up a scar may form which is associated with permanent vision loss" says Clin Assoc Prof Tan.
In certain patients with advanced forms of AMD and vision loss that is permanent, the SNEC Visual Rehabilitation service comprising a multi-disciplinary team of specialised optometrists, occupational therapists and social workers can provide comprehensive advice on ways to better adapt to their worsening vision with visual aids, assistive devices and digital technology, in addition to providing emotional and social support to the individual patient. Please ask your treating doctor for more information.
Click on page 2 to read about
how to treat and prevent macular degeneration.