Retina, Camera of Eye
Seek immediate medical attention if you suddenly have floaters, flashes or reduced vision
The eye functions like a camera the structures such as the cornea and lens focus the light on to the retina; the pupil acts like a camera diaphragm, regulating the amount of light that enters the eye.Retina is the light sensitive tissue that lines the inner wall of the eye. The retina converts the visual image in to a signal that the brain can capture. if the film of a camera is defective, one doesn't get good photos. Similarly if the retina is affected, we don't see well. Retinal diseases vary widely, but most of them cause visual symptoms. Retinal diseases can affect any part of your retina, a thin layer of tissue on the inside back wall of your eye. The retina contains millions of light-sensitive cells (rods and cones) and other nerve cells that receive and organize visual information. Your retina sends this information to your brain through your optic nerve, enabling you to see.
Treatment is available for some retinal diseases. Depending on your condition, treatment goals may be to stop or slow the disease and preserve, improve or restore your vision. Untreated, some retinal diseases can cause severe vision loss or blindness.
Many retinal diseases share some common signs and symptoms. These may include:
- Seeing floating specks or cobwebs
- Blurred or distorted (straight lines look wavy) vision
- Defects in the side vision
- Lost vision
You may need to try looking with each eye alone to notice these.
When to see a doctor
It's important to pay attention to any changes in your vision and find care quickly. Seek immediate medical attention if you suddenly have floaters, flashes or reduced vision. These are warning signs of potentially serious retinal disease.
Common retinal diseases and conditions include:
- Retinal tear. A retinal tear occurs when the clear, gel-like substance in the center of your eye (vitreous) shrinks and tugs on the thin layer of tissue lining the back of your eye (retina) with enough traction to cause a break in the tissue. It's often accompanied by the sudden onset of symptoms such as floaters and flashing lights.
- Retinal detachment. A retinal detachment is defined by the presence of fluid under the retina. This usually occurs when fluid passes through a retinal tear, causing the retina to lift away from the underlying tissue layers.
- Retinal Vascular Occlusion. retinal vascular disease occur mainly secondary to hypertension, though non hypertensive may also get it. it is associated with drop in vision secondary to macular edema or vitreous hemorrhage.
- Diabetic retinopathy. If you have diabetes, the tiny blood vessels (capillaries) in the back of your eye can deteriorate and leak fluid into and under the retina. This causes the retina to swell, which may blur or distort your vision. Or you may develop new, abnormal capillaries that break and bleed. This also worsens your vision.
- Epiretinal membrane. Epiretinal membrane is a delicate tissue-like scar or membrane that looks like crinkled cellophane lying on top of the retina. This membrane pulls up on the retina, which distorts your vision. Objects may appear blurred or crooked.
- Macular hole. A macular hole is a small defect in the center of the retina at the back of your eye (macula). The hole may develop from abnormal traction between the retina and the vitreous, or it may follow an injury to the eye.
- Macular degeneration. In macular degeneration, the center of your retina begins to deteriorate. This causes symptoms such as blurred central vision or a blind spot in the center of the visual field. There are two types — wet macular degeneration and dry macular degeneration. Many people will first have the dry form, which can progress to the wet form in one or both eyes.
- Retinitis pigmentosa. Retinitis pigmentosa is a degenerative disease that affects the retina.
Risk factors for retinal diseases might include aging, having diabetes or other diseases, eye trauma, and a family history of retinal diseases.
Retinal diseases can be related to aging, diabetes or other diseases, trauma to the eye, or family history. To make a diagnosis, your ophthalmologist conducts a thorough eye exam and looks for abnormalities anywhere in the eye.
The following tests may be done to determine the location and extent of the disease:
- Amsler grid test. Your doctor may use an Amsler grid to test the clarity of your central vision. He or she will ask you if the lines of the grid seem faded, broken or distorted and will note where the distortion occurs on the grid to better understand the extent of retinal damage. If you have macular degeneration, he or she might also ask you to use this test to self-monitor your condition at home.
- Optical coherence tomography (OCT). This test is an excellent technique for capturing precise images of the retina to diagnose epiretinal membranes, macular holes and macular swelling (edema), to monitor the extent of age-related wet macular degeneration, and to monitor responses to treatment.
- Fluorescein angiography. This test uses a dye that causes blood vessels in the retina to stand out under a special light. This helps to exactly identify closed blood vessels, leaking blood vessels, new abnormal blood vessels and subtle changes in the back of the eye.
- Indocyanine green angiography. This test uses a dye that lights up when exposed to infrared light. The resulting images show retinal blood vessels and the deeper, harder-to-see blood vessels behind the retina in a tissue called the choroid.
- Ultrasound. This test uses high-frequency sound waves (ultrasonography) to help view the retina and other structures in the eye. It can also identify certain tissue characteristics that can help in the diagnosis and treatment of eye tumors.
- CT and MRI. In rare instances, these imaging methods can be used to help evaluate eye injuries or tumors.
Treatment of retinal disease may be complex and sometimes urgent. Options include:
Scleral buckle. The main goals of treatment are to stop or slow disease progression and preserve, improve or restore your vision. In many cases, damage that has already occurred can't be reversed, making early detection important. Your doctor will work with you to determine the best treatment.
Vitrectomy -Vitrectomy is a surgical procedure undertaken by a specialist where the vitreous humour gel that fills the eye cavity is removed to provide better access to the retina. This allows for a variety of repairs, including the removal of scar tissue, laser repair of retinal detachments and treatment of macular holes. Once surgery is complete, saline, a gas bubble or silicone oil may be injected into the vitreous gel to help hold the retina in position.
- Using a laser. Laser surgery can repair a retinal tear or hole. Your surgeon uses a laser to heat small pinpoints on the retina. This creates scarring that usually binds (welds) the retina to the underlying tissue. Immediate laser treatment of a new retinal tear can decrease the chance of it causing a retinal detachment.
- Shrinking abnormal blood vessels. Your doctor may use a technique called scatter laser photocoagulation to shrink abnormal new blood vessels that are bleeding or threatening to bleed into the eye. This treatment may help people with diabetic retinopathy. Extensive use of this treatment may cause the loss of some side (peripheral) or night vision.
- Freezing. In this process, called cryopexy (KRY-o-pek-see), your surgeon applies a freezing probe to the external wall of the eye to treat a retinal tear. Intense cold reaches the inside of the eye and freezes the retina. The treated area will later scar and secure the retina to the eye wall.
- Injecting air or gas into your eye. This technique, called pneumatic retinopexy (RET-ih-no-pek-see), is used to help repair certain types of retinal detachment. It can be used in combination with cryopexy or laser photocoagulation.
- Indenting the surface of your eye. This surgery, called scleral (SKLEER-ul) buckling, is used to repair a retinal detachment. Your surgeon sews a small piece of silicone material to the outside eye surface (sclera). This indents the sclera and relieves some of the force caused by the vitreous tugging on the retina. This technique may be used with other treatments.
Evacuating and replacing the fluid in the eye. In this procedure, called vitrectomy (vih-TREK-tuh-me), your surgeon removes the gel-like fluid that fills the inside of your eye (vitreous). He or she then injects air, gas or liquid into the space.
- Injecting medicine into the eye. Your doctor may suggest injecting medication into the vitreous in the eye. This technique may be effective in treating people with wet macular degeneration, diabetic retinopathy or broken blood vessels within the eye..