Responsible for sending important codes to the brain so it can process visual images, the retina is in the back of the eye and contains specialized photoreceptor cells. The cells are called cones and rods, and they make up the retina’s complex tissue. There are many retinal diseases that can hinder how a person sees and processes visual information. The main types of retinal diseases are diabetic retinopathy, age-related macular degeneration, retinal detachment, eye cancer and inherited retinal degenerations. These disorders can lead to partial or full blindness.
Diabetic retinopathy (DR) is one of the major causes of blindness. It is the result of complications from diabetes, type 1 or type 2. When a person’s blood sugar is uncontrolled, his or her retinal blood vessels can become damaged. This type of retinal disease often goes undetected, but it can be prevented if one manages blood sugar levels and goes to scheduled yearly eye exams.
One of the most prevalent retinal diseases that causes vision loss in people age 65 or older is age-related macular degeneration. This disease causes the loss of central vision and leaves only the peripheral vision intact. It comes in two forms: wet, or neovascular; and dry, or non-neovascular. Wet macular degeneration results in new blood vessel growth in the parts of the eye that shouldn’t have blood vessels. Dry macular degeneration is caused by the thinning and aging of the macular tissues and typically results in yellow spots around the person’s macula.
Retinal detachment is when the retina is separated from the choroids, the layer of blood vessels that supply nutrients and oxygen to the retina. When this disease occurs, the eye doesn’t receive the necessary oxygen. This can result in permanent vision loss, but early detection and treatment can stop this disease from progressing.
Other types of retinal diseases include eye-specific cancers, such as retinoblastoma and ocular melanoma. Retinoblastoma commonly affects children, and it is a cancer that develops in the retina. It occurs when the retina’s nerve cells have genetic mutations that cause them to grow a mass of cells, called a tumor, inside the eye. Ocular melanoma is similar to skin cancer, and it develops in the melanin-producing cells in the eye. This disease sometimes is difficult to detect because it doesn’t have many early signs or symptoms.
Some people inherit retinal diseases from their family gene pool. An example of this type of disease is retinitis pigmentosa, which damages the retina and leads to incurable blindness. The first symptoms of this retinal disease typically include decreased vision during the night or in low light as well as the loss of peripheral vision. Other inherited retinal diseases include cone-rod dystrophy, retinoschesis and Usher syndrome.