A thin layer of tissue, the retina has millions of light-sensitive cells that organize visual images. The retina sends the information to the brain via optic nerve enabling us to see. Retinal diseases can affect any portion of the retina and may cause total visual impairment. Diseases affecting a part of the retina affect peripheral vision. Here are some of the common types of retinal diseases.
A complication of diabetes, diabetic retinopathy destroys the blood vessels of the retina. Initially, it may not have any symptoms but can eventually lead to blindness. The disease can affect anybody suffering from Type 1 or Type 2 diabetes. As the condition progresses, the symptoms include:
- Blurred vision
- Impaired colour vision
- Empty areas in the vision
Large quantity of sugar in blood can lead to blockage of tiny blood vessels nourishing the retina thereby cutting off blood supply. Because of this eyes attempt to grow new vessels. Sadly, these vessels don't develop properly, thereby leaking blood. The disease affects both the eyes and the best way to prevent it is careful management of diabetes.
Some of the complications of the disease are:
- Vitreous haemorrhage: The new vessels may bleed into the vitreous, a clear jelly-like substance, in the centre of the eye resulting in floaters and clouding of vision.
- Retinal detachment: Abnormal number of blood vessels may lead to the growth of scar tissue that pulls the retina away from the eye's back. It may cause severe vision loss.
- Glaucoma: New blood vessels growing in front part of the eye may interfere with the normal fluid out of the eye thereby elevating the intraocular pressure. This pressure can damage the eye's optic nerve.
Macular degeneration or age-related macular degeneration damages the macula - the central portion of the retina responsible for central vision. Dry and Wet AMD are the two types of the disease.
Causes and risk factors
The exact cause of the disease is not known and it is generally associated with aging. Studies have shown that there is a genetic component to the disease and besides affecting older population, the disease also affects the female population. Strong evidences suggest that smoking is high on the list of risk factors for the disease. Other risk factors include
- High blood pressure
There is no cure for macular degeneration, but timely treatment can result in visual improvement or at least retard it’s progression. The earlier the disease is diagnosed the better are the chances of treatment. Eating a balanced diet, protecting eyes from UV rays and quitting smoking are some of the other recommendations by ophthalmologists to control the disease. Nutritional supplements may also be advised.
Retinal detachment needs instant attention failing which it may result in permanent vision loss. It happens when the retina separates from the back of the eye and it needs to be reattached for the eye to function properly. The symptoms of this condition are:
- Sudden appearance or increase in floaters
- Distortion of vision
- Sudden appearance of flashes of light
The condition happens when the retina becomes thin and brittle and pulls away from the underlying layer. It may also be caused due to direct injury to the eye.
The condition can usually be treated effectively through surgery although visual recovery can take weeks to months.