You will most likely have heard of eye problems like cataracts, myopia (short-sightedness), presbyopia (far-sightedness), astigmatism and glaucoma, but there are many more eye conditions that are not only common, but can be very serious – even leading to loss of sight. Here is top ophthalmologist Praveen Patel's guide to five eye conditions you may not know about, but should!
The retina is the light-sensitive layer at the back of the eye. It is crucial for sight, as it is made up of cells that convert light into electrical signals, which travel to the brain and form the image you see. However, the retina can start to peel away from the layer underneath, detaching from the blood vessels that bring it the oxygen and nutrients it needs, starving the light-sensitive cells necessary to see.
The macula is a small oval part of the retina, which is responsible for our central vision. It has a high density of cone cells (which provide colour vision) and the macula therefore provides the high-definition colour vision we experience in well-lit areas. However, aging and other factors (genetics, smoking, etc.) can cause cells in the macula to lose function, making them less effective in detecting light, which leads to a deterioration in central vision. Everything becomes blurred – reading becomes difficult, colours appear faded and people’s faces can be difficult to distinguish. The earliest symptoms however, can be much more subtle and can include failing vision at dawn, dusk and in poorly-lit environments. This usually occurs in older people, and is often known as age-related macular degeneration (AMD) or macular degeneration. There are two distinct variations of AMD.
Diabetes can affect the body in a number of ways, including the eyes. To function, the retina needs a constant blood supply, but the regular high levels of blood sugar caused by diabetes can cause the tiny blood vessels supplying the retina to bulge, bleed and begin to form scar tissue, which can have devastating effects on your vision if left untreated. Alternatively, high levels of blood sugar together with high blood pressure and elevated blood cholesterol levels can lead to the blockage of tiny blood vessels in the retina, which leads to problems with the function of light-detecting photoreceptor cells, leading to loss of vision.
Frequently seen as a result of a range of retinal conditions including diabetic retinopathy, retinal vein occlusion, and conditions which cause inflammation in the eye (uveitis), macular oedema describes swelling in the macula due to a build-up of fluid leaked from damaged blood vessels. This swelling can distort vision, and leads to loss of vision if severe or untreated.
Retinal vein occlusion is when one of the blood vessels that carries blood away from the retina becomes blocked, usually by a clot, or by pressure from a nearby hardened artery. This blockage causes leakage of blood and other fluids into the retina, which in turn causes oedema, swelling, bleeding into the retina, and prevents sufficient oxygen reaching the retina. It is one of the most common causes of sudden, painless loss of sight.
If you are experiencing any problems with your vision, you should consult your doctor or an ophthalmologist.