Diabetes causes a group of eye problems that impact different areas of the eye. Rapid changes in blood sugar levels can cause vision to fluctuate even if no eye disease is present. The eye complications are common; development of these complications may also be related to the blood sugar levels and/or the duration of the diabetes. Each of these complications can be serious and lead to significant loss of vision.
Diabetic Retinopathy: Non-Proliferative
The elevated levels of glucose in the blood damages small blood vessels, or capillaries, like those found in the retina. This damage is called diabetic retinopathy. The early phase of diabetic retinopathy, or non-proliferative retinopathy, is characterized by small hemorrhages in the retina and changes in the capillaries. The capillaries begin to leak, which causes areas of the retina to swell. Patients may not notice any changes in vision at this stage.
Macular Edema
If the capillaries that are leaking fluid into the retina are close to the macula, the patient may notice a decrease in visual acuity. According to the International Diabetes Foundation, macular edema is the most common cause of vision loss in patients with earlier stages of diabetic retinopathy. Macular edema can be treated by laser therapy with generally good results.
Diabetic Retinopathy: Proliferative
As capillaries are damaged, portions of the retina begin to become ischemic—these areas do not get enough blood. To compensate, the retina begins to make new blood vessels that are more delicate than the original blood vessels. These blood vessels can break and bleed into the vitreous, which is the jelly inside the eye; the retina may detach because of scar tissue from the new blood vessels. The patient would notice floaters and a decrease in vision. This condition is sight-threatening and usually requires extensive laser treatment and sometimes vitrectomy surgery.
Glaucoma
Patients with diabetes are 40 percent more likely to develop glaucoma, according to the American Diabetes Association. The risk increases with the duration of diabetes and with age. If glaucoma is not treated, it can lead to major vision loss. The treatment is similar to glaucoma therapy in people without diabetes—eyedrops or surgery.
Cataracts
The American Diabetes Association states that people with diabetes are 60 percent more likely to develop cataracts. Cataracts also develop at a younger age in people with diabetes. When a cataract is removed in a patient with diabetes, any retinopathy can get worse. The eye surgeon may make sure that the retinopathy is treated before any cataract surgery.
