RETINA – DIABETES

Kaskaloglu Eye Hospital also diagnoses and treats retinal diseases caused by diabetes, macular degeneration and other causes. The hospital’s main diagnostic device is OCT (optical coherence tomography) and digital fluorescein angiography. The major treatment device is the argon laser. A major breakthrough in the treatment of macular degeneration is anti-VGEF (Lucentis, Eyelea).

Diabetic retinopathy:

Diabetic retinopathy is the most common diabetic eye disease and a frequent cause of blindness in adults. It is caused by changes in the retina’s blood vessels. However, blindness caused by diabetes is preventable with proper control of diabetes and with yearly eye examinations.

Diabetes causes a problem with the blood vessels in the body. The blood vessels begin to leak fluid, blood and protein. In the eye, this leakage is seen in the retina as retinal bleeding and swelling. This blood and swelling interferes with the normal function of the eye, resulting in decreased vision. If this condition is not corrected, visual loss can be permanent. This type of retinopathy is called background, or non-proliferative, retinopathy.

Eventually, the abnormal blood vessels in the eye begin to grow. These abnormally growing blood vessels are very fragile, and especially prone to bleeding. These abnormal blood vessels may cause a large sudden hemorrhage, called a vitreous hemorrhage that can result in rapid complete loss of vision. Usually, this visual loss is not permanent, but vision may not return to normal after this hemorrhage. This type of retinopathy is called proliferative retinopathy.

The best treatment for diabetic retinopathy is prevention. All diabetics should check their own blood sugar daily and record the results in a journal. This should be shown to your primary medical doctor at each follow-up visit so that tight control of blood sugar can be achieved. This means that all fasting blood sugar measurements should fall within a very narrow range. If your blood sugar tends to fluctuate a lot, your doctor must adjust your medications and your diet to optimize control of your diabetes. This is the best way to prevent blindness from diabetes.

Diabetes can also cause premature development of cataracts. A cataract is a clouding of the lens of the eye, which can cause blurred vision, glare and difficulty focusing. The abnormal vessels in proliferative retinopathy are not limited to the retina of the eye. Sometimes, these abnormal blood vessels grow on the iris of the eye and cover the drainage angle. This blockage of the drainage angle results in accumulation of aqueous humor fluid in the eye, increased pressure in the eye, and, ultimately, in a type of glaucoma called neovascular glaucoma.

If prevention of diabetic retinopathy has failed, your ophthalmologist can use a laser to cauterize the abnormal blood vessels to stop the leakage of fluid and blood. However, these problems will continue to recur as long as the diabetes is not medically controlled.

Macular degeneration:

Macular degeneration is often related to aging and is thus often referred to as age-related macular degeneration. It is often abbreviated as AMD or ARMD. Most patients with AMD begin to notice problems sometime after age 50. AMD is the most common cause of legal blindness among people over age 60 in the Western world. The disease occurs in “dry” or “wet” forms. The cause of AMD is still unknown; however, researchers are exploring several theories as to how the disease develops.

AMD is a challenging disease for both patient and doctor because there are very few treatment options and no proven preventative therapy. Laser photocoagulation is the one treatment proven to be effective in clinical trials, but only a minority of patients with AMD are good candidates for treatment.

Photodynamic Therapy:

Visudyne was the first drug therapy approved for treatment of the wet form of macular degeneration. In this treatment procedure, the doctor injects Visudyne into your arm, then activates the drug as it passes through the retinal blood vessels by shining a low-energy laser beam into your eye. Visudyne is activated by the laser light, which produces a chemical reaction that destroys abnormal blood vessels. The procedure is virtually painless, according to Novartis, which makes the drug.

Any disease associated with rapidly growing tissue, including the formation of abnormal blood vessels, can potentially be treated with this technology. In addition to applications in cancer, photodynamic therapy has shown promise as a breakthrough treatment in ophthalmic, autoimmune and cardiovascular diseases.

Photodynamic therapy consists of a two-step process beginning with administration of the drug, or “photosensitizer,” by intravenous injection. While circulating in the bloodstream, the drug attaches to molecules called lipoproteins. Because cells undergoing rapid proliferation (cell division and growth) require a greater amount of lipoproteins than non-dividing cells, the drug is delivered more quickly and in higher concentrations to these types of cells.

Once the concentration of the drug reaches appropriate levels in target cells, it is activated with a pre-calculated dose of light at a particular wavelength much less damaging than the current thermal or hot laser treatment. Because the light is shone directly at the targeted tissue and the drug accumulates in these cells, it reduces damage to normal surrounding tissue, allowing for the treatment to be administered again as needed.

Because photodynamic therapy is a minimally invasive procedure that can be performed on an out-patient basis, it appears to be a cost-effective alternative to other treatments. The type of light source used varies depending on the indication being treated. In ophthalmology, diode laser light is shone through the slit lamp of a microscope into the patient’s eye.