What is the retina?
The retina is the innermost layer in the back of the eye and is the portion of the eye that receives light. It contains nerves and light-sensitive cells called rods and cones. Rods are responsible for vision at low light and cones are responsible for vision at daylight or bright light as well as color vision. The function of the retina is to receive light that passes through the lens and converts the light into neural signals, which are transmitted to the brain for visual recognition. The retina is crucial for vision.
Damage to the retina is called retinopathy. Retinopathy has many causes and leads to visual impairment.
What causes damage to the retina?
Retinopathy usually occurs due to other medical conditions affecting the blood vessels in the retina. Some common causes are:
- Diabetes: The blood vessels start deteriorating in diabetes. Deteriorated blood vessels can become blocked or deformed and cause fluid accumulation and swelling in the retina, leading to decreased vision. The blood vessels can also become unstable and start bleeding. Bleeding can lead to irritation, scarring, and decreased vision. This takes years to develop and is also called diabetic retinopathy.
- Hypertension (high blood pressure): Damage to the retina due to hypertension is also called hypertensive retinopathy. Hypertension can cause bleeding in the blood vessels of the retina. There may not be any symptoms of hypertensive retinopathy in the early stages and it may be diagnosed during a routine eye exam.
- Serous retinopathy: This involves the build-up of serous fluid in the retina, leading to decreased vision. Serous retinopathy can occur due to certain medications like steroids or stress. Stress increases the level of steroid hormones in the body.
- Retinopathy of Prematurity (ROP): This occurs when a baby is born prematurely or if the birth weight is low. The blood vessels in the retina are not matured. There may be no symptoms in the early stages but can ultimately lead to retinal detachment and blindness.
- Tumors: Tumors involving the retina such as retinoblastoma.
- Retinitis pigmentosa: An inherited disease that slowly degenerates the retina, causing loss of night and side vision.
- Retinal tears and retinal detachment: The vitreous fluid is a clear, gel-like substance that fills the large cavity of the eye, which is lined by the retina. At birth, this gel is attached to the retina, however, with increasing age, the gel separates from the retina and causes retinal tears and detachment. Usually, this occurs without any specific cause.
- Macular degeneration: The macula is an oval spot located near the center of the retina. In macular degeneration, the center of the retina begins to deteriorate. This causes blurring of vision or blind spot in the visual field.
- Other systemic medical conditions and infections:
What are the symptoms of a damaged retina?
- Dim vision
- Blurring of vision
- Flashes of light
- Peripheral shadows: shadows in the edges of the eyes
- Floaters: appearance of floating specks, cobwebs, or lines
- Black spots
- Distorted shapes
- Difficulty reading or performing tasks that require detailed vision like embroidery or painting
- Blind spots
- Decreased or loss of peripheral vision
- Sudden loss of vision
How is retinal damage diagnosed?
Detailed history taking, along with specialized eye tests may be done, including:
Early retinal disease sometimes presents no symptoms and may be diagnosed only on routine eye exams. Blood and radiological investigations to identify underlying conditions that cause retinal damage may be required.
Can a damaged retina be cured?
Early diagnosis and treatment can help stop the progression of the disease as well as loss of vision, and aid in vision restoration. The time taken for the vision to be restored depends on the severity of the disease. There is a possibility that vision may never fully recover. There are several treatment options available to treat a damaged retina.
One or multiple treatments can be combined, including:
- Laser surgery
- Photocoagulation abnormal blood vessels
- Cryopexy: Extreme cold therapy used to treat the retinal tears
- Injecting air or gas to treat retinal detachment
- Injecting medication into the eyes
- Vitrectomy: Surgery to remove the vitreous fluid
- Retinal prosthesis: This can help restore vision to those who have blindness. A small electrode chip is implanted in the retina that receives input from a video camera attached to a pair of eyeglasses
- Treatment of underlying medical conditions
- Diet and lifestyle modifications to improve retinal strength: A healthy diet rich in nutrients (especially vitamin A), adequate rest, and adequate hydration with management of physical and emotional stress
- Avoiding eye stress by taking breaks from the screen or while reading