Age Related Macular Degeneration
The macula is the central area of the retina. The retina is a thin membrane located in the inside of the eye that acts like the film of a camera, capturing the image that will be transmitted to the brain through the optic nerve. We use the macula to see details, colours, read small print and discriminate faces amongst others.
Age-related Macular Degeneration (AMD) is a common eye disorder that affects the macula, the central part of the vision. AMD can affect one or both eyes. AMD is the most common cause of severe loss of vision in patients over the age of 50.
There are two types of AMD - dry or atrophic and wet or exudative.
In dry AMD there is loss of photoreceptors; the retinal cells that capture the image.
In the wet form of AMD abnormal blood vessels grow underneath the macula. These abnormal blood vessels can lead to the formation of a blister or retinal pigment epithelium detachment (PED), leakage of serum or fluid or bleeding under and/or inside the macula. These changes usually lead to the development of a scar in the macula and the consequent reduction of vision.
It is important to remember that AMD does not cause complete blindness equivalent to being in total darkness; affected patients usually maintain their peripheral or roundabout vision as the retina surrounding the macula continues to function normally. We must note that the peripheral retina is normally used only for navigation purposes as it is not capable of picking up small details or objects as the macula is.
AMD can make it difficult for affected patients to read, recognise people, drive, or perform tasks that require the use of accurate central vision.
Common symptoms of AMD are reduction of vision, blurring or distortion of central vision.
Without treatment, vision loss may be quick, severe and irreversible.
It is sometimes necessary to carry out investigations both initially and at regular intervals to determine whether you present the dry or the wet form of AMD, whether the lesions are active or not and treatable or not. The most commonly requested tests are Fundus Fluorescein Angiography (FFA) and Optical Coherence Tomography (OCT).
During FFA a dye is injected into a vein in the patient's arm and flash photographs are obtained through dilated pupils. FFA provides a detailed view of the macular blood vessels.
OCT is a non-contact test that is analogous to ultrasound but uses light instead of sound to image the macula by means of cross-sectional images similar to a histopathological microscope section. OCT can be very useful to determine the presence or absence of fluid, objectively determine the retinal thickness and response to treatment.
Treatments for wet AMD most commonly include the intraocular injection of anti-vascular endothelial growth factors (anti-VEGF) and/or alternatively, Photodynamic Therapy (PDT). The two treatment modalities can be carried out independently or in combination. Professor Stanga will discuss with you the best option for you.