ARMD
Age-related macular degeneration (AMD or ARMD) is the commonest cause of vision loss in those aged over 50. It affects the central area in the retina called the macula and causes a gradual loss of central (but not peripheral) vision. Central vision is needed for detailed work and for things like reading and driving. The disease does not lead to complete blindness as the peripheral vision is maintained. There are two types of macular degeneration – dry and wet.
Dry AMD
This is the most common form and occurs in 9 out of 10 cases. This condition affects a layer of cells underneath the retina called the Retinal Pigment Epithelium (RPE) and can be regarded as a ‘wear and tear’ process. Dry AMD is a very gradual process and it can take several years for vision to become seriously affected. Many people with dry AMD do not totally lose their reading vision.
Wet AMD
Wet AMD is also known as neovascular or exudative AMD. It occurs in about 1 in 10 cases. It tends to present more suddenly than dry AMD and is more likely to cause severe visual loss over quite a short time - sometimes just months. In wet AMD, abnormal blood vessels grow under the retina and this is called choroidal neovascularisation.The blood vessels are fragile and tend to leak blood and fluid which impairs the function of the macula and affects vision.
What are the symptoms of age-related macular degeneration?
AMD typically causes blurring of central vision and difficulty with reading. It causes distortion where straight lines look wavy and also objects can look smaller or larger in the affected eye compared to the other. If you are aware of a sudden onset of blurring or distortion then you should see your optician or doctor as soon as possible.
Treatment
At the present time, dry AMD is not treatable but there are ways of maximising vision and improving eye health. Magnifiers can be used to improve reading vision and a diet rich in leafy, green vegetables can reduce the risk of progression. There are also vitamin supplements available (look for AREDS formula) that can also reduce the risk of progression.
There are treatments available for wet AMD and they are more beneficial the earlier treatment is commenced. The treatments involve injections into the eye of anti-growth factor agents (anti-VEGF) to reduce the leakage of fluid from abnormal blood vessels under the retina. The two drugs used in my practice are Ranibizumab (Lucentis) and Aflibercept (Eylea). They are both given as an initial course of 3 injections at one monthly intervals. Further injections may be required at monthly intervals with Lucentis and two monthly intervals with Eylea. With treatment vision remains stable in 90% of patients and improves in up to 40%.
