Diabetes is the leading cause of visual impairment in the United States among patients below the age of 50. Many of the patients who suffer a loss in vision first present for eye examination when, unknown to the patient, the eye disease is already advanced. A few others lose vision despite meticulous eye care. With proper and timely treatment the likelihood of losing vision as a result of diabetic eye disease is much less than in the past.
Diabetes is the leading cause of visual impairment in the United States among patients below the age of 50.
Diabetes is primarily a disease of tiny blood vessels, called capillaries, the thin vessels that connect veins and arteries and act in the circulatory system as the loading docks for nutrients, oxygen, carbon dioxide, and waste products. The damage to the capillaries is cumulative and, as we currently understand it, dependent upon the total time and amount that the blood sugar is above normal. In insulin-dependent diabetes where the onset is often very abrupt, this accumulation of the effects of abnormal blood sugar usually does not show up as any sort of visual problem until at least five years after the initial diagnosis.
In the adult-onset non-insulin-dependent type of diabetes, eye disease can show up considerably earlier for the simple reason that diabetes may have been smoldering at a very low level for a number of years prior to the time that the diagnosis is actually made.
Diabetic Visual Changes That are Not Retinopathy
Besides the accumulation of damage to small blood vessels as a result of high blood sugars, the level of blood sugar can more directly affect vision. Fortunately, these direct effects are not permanent. When the blood sugar is over about 200 for several hours or several days, the blood sugar causes the lens in the eye to swell and produces transient nearsightedness. This effect goes away once the blood sugar is corrected to a normal level. It is this effect that causes many adult-onset diabetics to experience severe visual blurring during the month or so immediately after diagnosis when blood sugar is being gradually brought into the normal range.
On the other end of the spectrum, some diabetics experience peculiar visual symptoms as the first hint of hypoglycemia, the circumstance when the blood sugar is so low that the brain and eyes are not being properly fed.
Vitreous bleeding causes your vision to suddenly change due to blood that blocks light from reaching the retina. A vitreous hemorrhage can result from a ruptured aneurysm in the eye, trauma to the eye, a retinal tear, a retinal detachment, a new leaky blood vessel (neovascularization caused by Diabetic Retinopathy, Retinal Artery or Vein Occlusion, Macular Degeneration, Carotid Artery Stenosis, etc.) or another underlying disease such as hypertension or sickle cell anemia.
Diabetes, high blood pressure, macular degeneration, sickle cell disease, history of previous retinal tear/detachment, family history of retinal tears/detachments, recent trauma. If you have diabetes, you are particularly susceptible because diabetes triggers the growth of abnormal blood vessels in the eye that are weak and which bleed easily. All diabetics should receive an eye exam once a year, or as directed by an ophthalmologist. Vitreous hemorrhage occurs more often in people over 50, but can occur at any age.
Symptoms of vitreous hemorrhage include sudden onset of:
- Blurry vision
- Light flashes
- Floaters (spots and cobwebs that trail across the field of vision)
- Reddish tint to vision
Minor hemorrhages often clot and heal over time, although it may take months for the floaters to disappear. Severe vitreous bleeding can be treated with a vitrectomy surgery +/- laser. A vitrectomy is a procedure that removes the vitreous gel and the blood from inside the eye, and replaces it with a special saline solution. Visual recovery depends on the underlying cause.