Diabetes
Are You a Diabetic?
A leading cause of blindness, Diabetic Retinopathy is a condition, in which the delicate blood vessels of the retina become damaged by the effects of diabetes. Patients with type-1 or type-2 diabetes may develop diabetic retinopathy. Diabetic retinopathy is often asymptomatic during the early stages of the disease. Only through routine eye exams can these changes be detected. Risk factors for the development of diabetic retinopathy include, level of blood glucose control and duration of diabetic disease.
Signs and symptoms
Diabetes is generally categorized in two main stages when involving the eye.
NPDR ( non-proliferative diabetic retinopathy )
The small vessels throughout the retina may leak making the retina swell causing what’s known as macular edema. Macular Edema occurs when fluid is built up in the retina which can lead to distorted vision, washed out colors, and overall blurry vision. Without treatment, macular edema can even lead to permanent vision loss.
PDR ( proliferative diabetic retinopathy)
PDR is the more severe form of diabetic eye diseases.When the retina starts undergoing a process known as angiogenesis, the growth of new blood vessels that stem from existing vessels. Angiogenesis is a chemical signal in your body that promotes these new blood vessels to form known as vascular endothelial growth factor (VEGF). Treatments for this can be found below. In addition to openly bleeding into the eye from these weak new vessels they can also create scar tissue which can impair vision of potentially lead into a retinal detachment causing complete vision loss. PDR can also create new vessels in the drainage system of the eye and cause high eye pressure / glaucoma which may lead to blindness.
In the back of the eye the retina is responsible for sending images to the brain. To function, the retina receives nourishment from the blood that enters through the central artery and exits through the central vein. When any of the blood vessels are compromised the retina does not have enough oxygen to function and the cells that make up the retina begin to die. To compensate for the lack of oxygen the body tries to make up for it by creating new blood vessels but these vessels are weak and fragile and break relatively easily leading to free flowing blood into the eye.
Diabetic Retinopathy Tests
A common test that is performed is OCT - Optical Coherence Tomography this test allows the doctor to look closely at the retina and also looking at your retina from a side perspective to see its overall thickness to check for swelling, fat deposits, abnormal fluid, detachments, degeneration, and much more.
Another common test that is performed is Fundus Photos. This allows the doctor to obtain a clear view of the retina. Although the doctor can physically see into your eye without the use of a camera this allows the doctor to note any changes and discrepancies between the initial photo and the photos taken later in the future. Whether it be an annual diabetic exam or follow visits pertaining to managing your current diabetic eye disease.
Your doctor may also order a Fluorescein Angiography to see the overall blood flow function. This test involves a dye ( fluorescein ) is injected into a vein, into your hand / arm. Then with the same camera used to take Fundus Photos a filter is added in contrast with the dye and highlight areas that are abnormal. The dye runs through your blood vessels into the vessels into the eye and make show areas that are blocked, growing new vessels, leaks, or other abnormalities.
Prevention/Management
For diabetics or individuals labeled as borderline diabetic should consider their options to prevent any sort of vision loss.
Treatment
A common treatment for a diabetic retinopathy is intravitreal injections. A particular injection with the name of Avastin also known as bevacizumab, (anti-vascular endothelial growth factor) is used to stop the abnormal blood vessels from growing in the retina. This medication reduces some of the swelling of the macula, slowing vision loss, and clear some blood. Prior to the injection you will have plenty of anesthetics to numb the eye and to alleviate any discomfort. After the injection is administered in the eye you may feel slight pressure and see the medication floating around.Depending on the severity the patient may be required to have multiple injections in multiple different series of injections to bring back stability to the blood vessels of the retina.
Laser surgery is another option for diabetic patients who have abnormal blood vessels, swelling of the retina, or bleeding in the retina. The laser itself is done in the office and require whichever eye that needs laser to be dilated. A small numbing drop is applied and a hand-held lens is placed on your eye and the laser begins. Patients that have severe bleeding and or recurrences may need more than laser treatment.
For patients with advanced PDR/Retinal Detachment your ophthalmologist may recommend a surgery known as Vitrectomy. This outpatient procedure will be performed to remove any large amounts of blood that is in the eye as well as any scar tissue, additional laser might be used to make sure the areas that are leaking are sealed. A gas bubble, oil, or silicone may be used to hold down the retina in the case of a retinal detachment. If silicone is used another surgery will be needed to remove the silicone.