The retina is the layer at the back of the eye that senses light and sends images to the brain. It is the innermost layer inside the eyeball.
Retinal diseases can be associated with ageing, diabetes, hypertension, high myopia,trauma to the eye or of genetic origin.
Optical Coherence Tomography (OCT)
Retinal Angiography (FFA - Fundus Fluorescein Angiography)
Screening program for Diabetic Retinopathy
Retinal surgeries like cryotheraphy, scleral buckling, vitrectomy, endolaser, membrane peeling, to name a few are carried out using the top of the range vitreo-retinal surgical equipment. All procedures are done as day care surgery.
Retinal detachment is a separation of the retina, which is the light-sensitive layer in the back of the eye from its outer layers. The retina is a transparent membrane in the back of the eye. It helps you see the images that are focused on it by the cornea and the lens. Retinal detachments are often associated with a tear or hole in the retina through which eye fluids may leak into the sub-retinal space. This causes separation of the retina from the underlying layers.If not treated early, retinal detachment can cause permanent vision loss.
Small holes and tears are treated with laser or cryopexy. These procedures are usually performed in the clinic as an outpatient procedure. With a laser, tiny scars are made around the hole to "weld" the retina back into place. Cryopexy freezes the area around the hole and helps reattach the retina. These procedures are done for early onset cases or those without detachment as a preventive measure.
Retinal detachments are generally treated with surgery. In some cases a scleral buckle, a silicon band, is sutured to the eyeball from the outside to gently indent the wall of the eye against the detached retina. Avitrectomysurgery may also be performed in a large number of cases. Here, 3 tiny incision in the sclera (white of the eye) are made to gain access to the vitreous. Next, a small instrument called a cutter is placed into the eye to remove the vitreous, a gel-like substance that fills the center of the eye and helps the eye maintain its shape. Air and Gas is injected to into the eye to replace the vitreous and reattach the retina; the gas pushes the retina back against the wall of the eye. During the healing process, the eye secretes the fluid that gradually replaces the gas and fills the eye. With all of these procedures, either laser or cryopexy is used to stick the retina back in place. Silicon Oil is used in some cases with advanced problems like large or giant tears and proliferative retinopathy.
With these latest procedures, over 90 percent of those with a retinal detachment can be successfully treated, although sometimes a second surgery is needed. However, the final visual outcome is not always predictable. The final visual result may not be known for up to several months following surgery. Even under the best of circumstances, and even after multiple attempts at repair, treatment sometimes fails and vision may eventually be lost. Visual results are best if the retinal detachment is repaired before the macula (the center region of the retina responsible for fine, detailed vision) detaches. That is why it is important to contact a specialist immediately if you see a sudden or gradual increase in the number of floaters and/or light flashes, or a dark curtain over the field of vision.
Tests will be done to check the retina and pupil response and your ability to see colors properly. These may include:
The unsuccessful reattachment of the retina might be a result of formation of new/ fresh breaks in the retina, scarring or membrane formation, uncontrolled swelling of the retina and choroid, uncontrolled eye pressure and inflammation. These could be one of the reasons for recurrence and loss of vision.
What happens will depend on the location and extent of the detachment, history of previous eye surgeries and early treatment. If the macula has not detached, the results of treatment can be excellent. Most retinal detachments can be repaired, but not all of them. The exact prognosis can be determined only after a thorough eye examination.
Use protective eye wear to prevent eye trauma. Control your blood sugar carefully if you have diabetes. See your eye care specialist at least yearly, especially if you have risk factors for retinal detachment like myopia or family history of retinal problems.
Macular degeneration, often age-related macular degeneration (AMD or ARMD), is a medical condition that usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in "dry" and "wet" forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD).
The retina is a network of visual receptors and nerves. It lies on the choroid, a network of blood vessels which supplies the retina with blood.
In the dry (nonexudative) form, cellular debris called drusen accumulates between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.
Diabetes can affect virtually every part of the eye, such as the Lens (Early onset Cataract), Optic and other cranial nerves (Neuropathy, Neuritis), Eyelids (repeated infections), and the Retina. Retinopathy is the most common and characteristic complication of diabetic eye disease.
As with other organs, the problems start with a decrease in blood supply to the retina. This leads to lack of oxygen to the retinal layers and creates a chain reaction in the retina leading to progressive disease. The earliest stage is called Non-proliferative or Background Retinopathy. Small blood clots (hemorrhages) and areas of swelling (exudates) develop in the retinal layers. The patient usually does not have any visual complaints at this stage because the central retina is spared.
The center of the retina (Macula), which is responsible for fine visual function, may develop swelling from retinal vessel leakage. This macular swelling (Maculopathy) can cause visual loss. The patient may not notice early macular swelling causing subtle visual defects such as distorted vision or mild blurring, and hence the importance of routine eye examinations in diabetics is critical.
This can progress to the next stage called Proliferative Retinopathy, i.e., the formation of abnormal blood vessels (neovascularization) that grow out of the retina. These vessels will usually bleed into the vitreous, causing severe and sudden visual loss, or they pull on the retina resulting in a retinal tear. In many patients, bleeding and retinal detachment occur.
The most recent and useful test available for this is called OCT (Optical Coherence Tomography). This is a painless and quick scan of the macula, which gives us information about the thickness of the retina and any other abnormalities like swelling, membrane formation etc. The other important test is Retinal Angiography.
It is also known as Fluorescein Angiography. It is done in the OPD. A colored dye (fluorescein sodium) is injected in the vein and the patient sits in front of a retinal camera, which takes serial photos of the dye flowing through the retinal blood vessels. It can pick up early diabetic retinal damage, swelling and leakage from the retina at all stages of the disease, as well as help us predict the visual improvement that the patient can achieve after successful treatment.
The treatment depends on the type and stage of the retinopathy. Maculopathy can be treated with Intravitreal Injections of Anti VEGF drugs like Avastin, Lucentis and Macugen, or Steroids like Ozurdex or Triamcinolone, depending on the severity and risk factors. Multiple injections may be required to keep this condition under control. These injections will have to be supplemented with Laser treatment in most cases.
The treatment is usually by laser to the leaking blood vessels. However, patients with severe bleeding or retinal detachment involving the central vision usually require surgery. Laser treatments for either retinal swelling or leaky blood vessels are performed as an outpatient procedure. Treatments may be divided into several sittings over a few weeks, depending on the severity. The treatment is painless.
Vitreous surgery for Diabetic Retinopathy is done to remove blood, reattach the retina, or both. This procedure is called Vitrectomy. Fine microsurgical instruments such as scissors, picks, forceps, laser probe etc. are introduced into tiny openings in the side of the eye, and the procedure is usually done under local anesthesia as a day care procedure. In some cases, an expansible gas or silicon oil is injected in the eye to stabilize the retina after the surgery.
Good diabetic control along with good control of other medical problems like hypertension, kidney disease, cholesterol (lipids) produces many benefits, including slowing down the development of retinal complications. Even with excellent control, many patients may still develop retinopathy. Therefore, regular eye examinations are very important.
A patient with diabetes should have a dilated pupil examination of the retina at the time of diagnosis and a minimum of once a year for life. Some patients with early diabetic retinal disease may require more frequent examination.
Successful treatment of Diabetic Retinopathy depends on early detection and regular follow up. This is the best protection against severe loss of sight.