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The anatomy of the eye

2. Wet AMD
Wet AMD is less common but far
more serious. This form of AMD
happens when there is too much of a
substance called vascular endothelial
growth factor (VEGF) in the eye and
this substance causes the growth of
abnormal blood vessels under the
macula. As a result, these abnormal
blood vessels bleed and leak fluids
into the macula and cause a painless
but rapid loss of central vision. There
is blurring and severe distortion of
damage to the macula, a small area retina where the majority of cone cells vision when looking straight ahead.
located in the centre of the retina. are situated. This small area of the retina Wet AMD typically affects one eye first
is critical for sharp, detailed central but may eventually affect both eyes.
The retina is the thin layer of light- vision. The image focused on the macula
sensitive tissue lining the back of the is converted to electrical impulses, and Vision is lost much faster than
eye. The macula is extremely important the optic nerve carries these impulses with dry AMD. Eventually, the
as it is responsible for seeing fine details to the brain, where they are processed. bleeding and subsequent scarring
clearly. Patients with AMD lose the of the macula may lead to severe
ability to see fine details, both near DIFFERENT TYPES OF AMD and permanent loss of central
and in the distance. For example, a 1. Dry AMD vision. However, in most cases,
person with AMD will look at a clock This is the most common type of the peripheral vision is spared and
and see the outline of the clock but macular degeneration, and about there is no risk of going completely
will be unable to tell the time. 80% of people with AMD have the dry blind in the eye. Treatment
type. Dry AMD occurs when parts of includes lifestyle changes, sun
HOW VISION WORKS the macula get thinner with age and protection, vitamin supplements
To understand how AMD affects vision, small, yellow clumps of protein, called and anti-VEGF injections.
it is helpful to understand how the eye drusen, grow in the macula. Patients
works. Vision occurs when light enters complain of a slow, gradual loss of WHO IS AT RISK?
the eye through the pupil. The cornea central vision, but peripheral (side) You are more likely to develop
and lens in the front of the eye focus vision remains intact. While there is AMD if there are one or more of
light onto the retina at the back of the no treatment, early detection, lifestyle the following factors present:
eye. The retina is a light-sensitive layer changes and vitamin supplements • You are over 50 years
that lines the interior of the eye and is can slow down the progression of • Caucasian
made up of millions of specialised cells the disease. All macular degeneration • Have a family history of AMD
called rods and cones. The macula is a begins as ‘dry’, but 10 – 15% of patients • Smoke cigarettes or are
small yellow spot in the centre of the with dry AMD progress to ‘wet’ AMD. exposed to passive smoke

Age-related Macular Degeneration

IMAGE BY HTTPS://OPHTHALMOLOGYBREAKINGNEWS.COM/ Dry AMD Normal Wet AMD

(with bleeding)
healthy macula
(without bleeding)

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