I just recently purchased a mirrorless DSLR camera to pursue photography as a hobby. And as with any hobby, you start getting deeper into the experience and you start buying different lenses and other accessories. You also start studying different techniques to get the picture you want. However, using these equipment entails a lot of care or else, you end up with damage to critical parts of the camera (e.g. the lenses and the sensor). You either end up with costly repairs to restore the camera, or worst, you may need to replace it. Sadly, repairs may be difficult and damage may be more disabling in the one and only camera of your body, the eyes. One such condition, especially in older persons, is called macular degeneration. Let's talk about the eye first. Inside the eye, towards the back, is the retina. This is the part that transforms light into electrical signals that are then transmitted through the optic nerve to the brain, where the signals are interpreted as images that we see. Near the center of vision is the corresponding area on the retina called the macula. This area is responsible for sharp central vision. Someone with macular degeneration may experience blurring of vision in the central part of the visual field. Over time, this area can expand or form dark spots. Other complaints may include the following:
Straight lines appearing wavy
Trouble seeing distant objects
Problems seeing colors
Problems seeing details in faces or words
Peripheral vision is not affected so macular degeneration does not cause complete blindness, but people then have the tendency to look at objects from the ‘side’. Disruption of activities of daily living can then occur, especially for those highly dependent on a clear central vision like reading or driving. Both eyes are usually affected but the speed of progression can vary from eye to eye.
Age is the major risk for developing macular degeneration. This disease is more common for those 60 years old and above, especially among Caucasians. In some situations, it may occur in younger persons — more often in women than in men. Other risk factors may include:
A family history of macular degeneration – the risk is three-fold higher with a 1st degree relative having the condition;
Having a history of hypertension or high blood pressure; and
There are generally 2 types of macular degeneration:
- Drytype – This accounts for about 90% of all cases of macular degeneration. It happens when yellowish or off-white deposits called drusen develop in the macula. Small amounts of drusen do not cause any problems but as it increases in size and number, it starts causing damage, leading to the mentioned symptoms. Later, these can lead to thinning of the layers of light-sensitive cells in the macula.
- Wettype – In this type, blood vessels form underneath the macula in the choroid layer. These blood vessels then start either leaking fluid or bleed into the macula. In the long run, these blood vessels, with the fluid and blood, lead to scarring of the macula.
How does one know if he or she has macular degeneration? The only certain way to know is to see an ophthalmologist for a thorough eye examination. An Amsler grid may be used to identify areas in your visual field that may be distorted (e.g. wavy or even missing). Fundoscopy is done using a variety of instruments, but commonly using an ophthalmoscope to look inside the eye, particularly on the surface of the retina to look for changes related to macular degeneration. The eye doctor may also order fluorescein angiography, wherein a dye is injected in a vein in the arm, then a special light is shown through the eyes to check for abnormal blood vessels and leakage of the dye in the retina. Optical coherence tomography is a specialized technique wherein a detailed cross-sectional image of the retina and any relevant structures is obtained. This enables further diagnosis of macular degeneration without using a dye. The eye doctor may also refer patients to other doctors (e.g. an internal medicine specialist) for management of other problems that may contribute to macular degeneration like hypertension or diabetes.
So now you know you have macular degeneration. What can be done about it? There is really no cure for macular degeneration. Currently available modalities aim to decrease the amount of vision that may be lost. This is especially through for the wet type since this is more likely to cause visual impairment.
A study published in 2001 revealed that the use of antioxidant supplements (particularly those containing vitamins E and C, beta-carotene, and zinc) reduced risk of progression to advanced dry macular degeneration by 25% in 5 years. The caveat here is that the high dose of beta-carotene also increased the risk for lung cancer. A follow-up study published in 2013 where beta-carotene was replaced by omega-3 fatty acids and lutein + zeaxanthin showed that the latter may be a suitable substitute for beta-carotene. The dose preparation of the antioxidants in these studies are much higher than ones commercially available in multivitamin preparations. Whether or not the results of the studies are robust, the benefits and the possibility of side effects remain to be studied further. The wet form of macular degeneration can be managed using several modalities:
- Laser therapy – The laser destroys the abnormal blood vessels and prevents new ones from growing. This will help reduce visual loss in the early stages. However, the procedure causes scar formation at the site of treatment, hence there may be some treatment-related visual loss. This is nonetheless accepted to prevent further spread of the blood vessels.
- Photodynamictherapy – This involves injection of a drug that is light-activated. Once injected in the veins, a specialized laser is then used to activate the drug, closing the abnormal blood vessels while leaving the retina intact.
- Anti-vascular endothelial growth factor (anti-VEGF) medications can be injected directly into the eye to prevent the abnormal growth of the blood vessels. The drugs are injected using a very fine needle, under strict sterile techniques, by a board-certified ophthalmologist.
And there you have it! Whenever you start seeing ‘weird’ or distorted images, go to your eye doctor and have the most important camera you have checked!