Retina
The retina is a thin layer of tissue that lines the back of the eye on the inside and is located near the optic nerve. The purpose of the retina is to receive light that the lens has focused, convert the light into neural signals, and send these signals on to the brain for visual recognition.
Damage to retina can cause permanent blindness. Many conditions for example, retinal detachment, where the retina is abnormally detached from its usual position, can prevent the retina from receiving or processing light. This prevents the brain from processing this information, thus leading to blindness.
The retinal surgeons at Eknath Eye hospital, specializes in diagnosing and treating retina conditions such as diabetic retinopathy, age-related macular degeneration (AMD) and retinal detachment, all of which can lead to vision loss or blindness.
Common Retinal Diseases
Floaters
Floaters are spots in your vision and can be age-related. They can also occur in cases of severe near sightedness. Floaters can also be the result of a torn retina. If the tear isn’t repaired, then it can lead to retinal detachment. This is due to fluid accumulation behind the retina, causing it to separate from the eye.
Macular Degeneration
An age-related condition of the retina that causes central vision loss. It is very common in individuals over the age of 55 years. The symptoms include blurry central vision, warped straight lines, or difficulty focusing on fine details. Blind spots can also develop as the condition worsens. Providentially, there are treatments, such as an antioxidant supplement that can slow the progression by blocking unhealthy blood vessel development.
Diabetic Eye Disease
Diabetes patients are more susceptible to retinal damage. The symptoms include blurry vision, floaters or dark spots. However, laser surgery is a treatment that can help a person suffering from diabetic eye disease.
Retinal Detachment
Retinal detachment can occur when too much fluid accumulates behind the retina, causing the separation. There are other risk factors that increase the chances of retinal detachment too, such as:
Previous retinal detachment in the other eye
Genetic predisposition
Previous cataract surgery
The presence of other eye disorders
Eye injury
Also, if you suddenly notice floaters or you have had them and they have increased, see your doctor immediately. Other symptoms may include a decrease in vision or seeing a grey curtain in your field of vision.
Diagnosis of Retinal Diseases
Retinal disease can be associated with many causes. The following tests may be performed to determine the location and extent of the disease:
Ambler Grid Test: An Ambler grid is used to test the clarity of your central vision. The lines of the grid may seem faded, broken or distorted and notes are taken where the distortion occurs on the grid to better understand the extent of retinal damage. For macular degeneration, this test can be done 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 (oedema), to monitor the extent of age-related wet macular degeneration, and also to monitor responses to treatment.
Fluorescein Angiography: This uses a dye that causes blood vessels in the retina to stand out under a special light which helps to exactly identify closed blood vessels, leaking blood vessels, new abnormal blood vessels and subtle changes in the back of the eye.
Neocyanine Green Angiography: Neocyanine Green Angiographytest uses a dye that lights up when exposed to infrared light. The subsequent images show retinal blood vessels and the deeper, harder-to-see blood vessels behind the retina in a tissue called the choroid.
Ultrasound: High-frequency sound waves are used to help view the retina and other structures in the eye. This can also identify certain tissue characteristics that can help in the diagnosis and treatment of eye tumours.
CT and MRI: These imaging methods can be used to help evaluate eye injuries or tumours.
Retinal Diseases Treatment
The treatment of Retinal disease depends upon the causes and may be complex and sometimes urgent. The options include:
Laser surgery: This can repair a retinal tear or hole. Your surgeon uses a laser to heat small pinpoints on the retina which 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: The 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. Though, extensive use of this treatment may cause the loss of some side (peripheral) or night vision.
Freezing: In this process, called cryopexy, the 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 and then,the treated area will later scar and secure the retina to the eye wall.
Pneumatic retinopexy: This techniqueis used to help repair certain types of retinal detachment. It can be used in combination with cryopexy or laser photocoagulation.
Scleral buckling: This surgery is used to repair a retinal detachment by sewing 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 also be used with other treatments.
Vitrectomy: Which is evacuating and replacing the fluid in the eye? In this procedure, the 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.Vitrectomy may be used if bleeding or inflammation clouds the vitreous and obstructs the surgeon’s view of the retina. This technique may be part of the treatment for people with a retinal tear, diabetic retinopathy, a macular hole, an infection, eye trauma or a retinal detachment.
Injecting medicine into the eye: The doctor may suggest injecting medication into the vitreous in the eye. This technique might be effective in treating people with wet macular degeneration, diabetic retinopathy or broken blood vessels within the eye.
Implanting a retinal prosthesis: People who have severe vision loss or blindness owing to retinal disease may be a candidate for this surgery. One surgical option not widely available is called retinal prosthesis.