Diabetes mellitus is a condition in which the body can’t use or store sugar properly, elevating blood sugar levels. Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease’s affect on the retina is the main threat to vision.
When blood sugar gets too high, it damages the blood vessels in the eye, leading to diabetic retinopathy. Diabetic retinopathy is the leading cause of blindness in young and middle-aged adults. The longer someone has diabetes, the greater their chance of developing diabetic retinopathy.
Two Types of Diabetic Retinopathy
• Non-proliferative diabetic retinopathy or NPDR
• Proliferative diabetic retinopathy or PDR
NPDR is an early stage of diabetic retinopathy and is the most common form of diabetic retinopathy. The small blood vessels in the retina are damaged due to high blood sugar, causing them to leak fluid or bleed. This causes the retinal tissues to swell and form deposits called exudates. People with early or mild NPDR may not have any visual symptoms; however it can cause severe blurring.
PDR has the greatest risk of vision loss and typically develops in patients with significant or advanced NPDR.
PDR occurs when the blood vessels in the retina become so damaged or blocked that the retina becomes starved for oxygen. This stimulates the growth of new blood vessels on the retina (neovascularization). These new blood vessels are fragile and leak blood or fluid into the vitreous. Hemorrhages into the vitreous may be seen as large dark floaters or “cobwebs” with hazy vision, or in dense bleeding, a severe decrease in vision. They may also cause scar tissue to develop, which can pull on the retina causing a retinal detachment. Abnormal blood vessel growth on the iris may cause the eye pressure to increase damaging the optic nerve, as in the case of neovascular glaucoma.
Signs and Symptoms
The affect on vision varies widely, depending on the stage of the disease;
• Blurred vision (this is often linked to blood sugar levels)
• Floaters and flashes
• Wavy or distorted vision
• Sudden loss of vision
Diabetic patients require annual dilated eye examinations by an optometrist or ophthalmologist so problems can be detected and treated as early as possible.
Other problems that may develop are:
Macular Edema – the macula is the area of the retina that provides sharp vision in front of you. If fluid leaks into this area vision will become blurry
Retinal detachment – abnormal vessel frowth may cause part of the retina to pull away from the bak of the eyeball.
Treatment for diabetic retinopathy depends on the stage of the disease. The abnormal growth of tiny blood vessels is one of the most common problems treated. A laser procedure called pan retinal photocoagulation or PRP is usually the treatment of choice for this problem. With PRP, the retina specialist uses laser to destroy oxygen-deprived retinal tissue outside of the patient’s central vision. While this creates blind spots in the peripheral vision, PRP prevents the continued growth of the fragile vessels and seals the leaking ones. The goal of the treatment is to arrest the progression of the disease.
Vitrectomy is another surgery commonly needed for diabetic patients who suffer a vitreous hemorrhage. This involves removing the vitreous (gel-like substance that fills the center of the eye) in order to clear the blood.
Patients with diabetes are at greater risk of developing retinal tears and detachment. Tears are often sealed with laser surgery. Retinal detachment requires surgical treatment to reattach the retina to the back of the eye.
Researchers have found that diabetic patients who are able to maintain appropriate blood sugar levels have fewer eye problems than those with poor control. Diet and exercise play important roles in the overall health of those with diabetes. Diabetics should monitor their blood sugar closely with their primary care doctor or endocrinologist and be aware of their blood sugar range, as well as their A1C, a long term blood sugar reading that their doctor measures regularly.
Diabetics can also greatly reduce the possibilities of eye complications by scheduling routine eye examinations with an eye doctor. Many problems can be treated with much greater success when caught early.