1. Hemoglobin A1c under 7% ADA
Diabetic Retinopathy (DR) is a collective term we use to categorize the specific damage that diabetes causes to the eye. These can range from minor bleeds that do not affect visual acuity to total vision loss due to various diabetic-related complications. DR is normally painless and initially, most patients are not aware of any problem with their eyes or vision. Elevated glycosylated hemoglobin (HbA1c) is a strong risk factor associated with the development and progression of Diabetic Retinopathy (DR). The Diabetes Control and Complications Trial, which included patients with insulin-dependent diabetes, and the United Kingdom Prospective Diabetes Study, which included patients with non-insulin-dependent diabetes, both showed that tight control of blood sugar can reduce the incidence of retinopathy (retinal bleeding). The studies found that for every 1 absolute percentage point decrease in HbA1c, the incidence of retinopathy onset and significant progression decreased by approximately 35%.
2. Diabetics with systemic hypertension have a greater risk of diabetic retinopathy
Studies show that hypertension (higher than normal blood pressure) is associated with higher rates of the onset and progression of diabetic retinopathy and macular edema (swelling in the macula causing visual disturbance) in both types 1 and 2 diabetes. Even a patient with a modest increase in systolic or diastolic BP may be at an increased risk.
In patients with type 2 diabetes, hyperlipidemia (blood has too much cholesterol and triglycerides) combined with hypertension is associated with worse stages of retinopathy and increased accumulation of intraretinal exudation (trash from plasma). Both the Early Treatment Diabetic Retinopathy Study (ETDRS) and the Wisconsin Epidemiologic Study of Diabetic Retinopathy showed a relationship between total cholesterol and low-density lipoproteins and the frequency of hard exudates found in the retina.
4. Sleep Apnea should be ruled out.
The recurrent nocturnal hypoxemia (lower than normal blood oxygen at night), hypercapnia (elevated arterial carbon dioxide), and hypertension associated with obstructive sleep apnea may aggravate Diabetic Retinopathy and be a driving factor for more diffuse macular edema. It is also an independent risk factor for several systemic conditions like arterial and pulmonary hypertension, nocturnal stroke, and myocardial infarction (heart attack). In diabetic patients, it is also a factor for kidney disease and eventual renal failure.
5. Anemia needs to be ruled out.
Diabetic kidney disease, along with anemia, is thought to exacerbate the ischemic (not getting proper blood and oxygen) aspect of DR. Diabetes damages the kidney’s ability to produce erythropoietin, which is a hormone that protects red blood cells from damage. This causes red blood cells to die more quickly, leading to anemia. The ETDRS evaluated the effect of anemia and found that low hematocrit (<40% in men and <34% in women) was an independent risk factor for high-risk proliferative retinopathy and severe vision loss. Hematocrit is the percentage of red blood cells by volume in your blood.
6. Proteinuria (Protein in your urine)
A high prevalence of patients with insulin-dependent diabetes have high amounts of protein in their urine, known as proteinuria. This condition signals imminent renal failure. In addition to this complication, the presence of microalbuminuria (greater than normal albumin, which is a protein, in urine) has a direct relationship with kidney function and is often the first sign that the kidneys are becoming injured by diabetes. For these patients, physicians should ensure they have tight blood sugar control and recommend that they decrease their dietary intake of protein to reduce proteinuria and slow the progression to renal failure.
7. Stop Smoking
Smoking increases proteinuria, blood vessel wall damage, and vasoconstriction (narrowing of the blood vessels). Nicotine is known to cause severe retinal vasoconstriction, and smoking can cause an increase in circulating activated leukocytes (white blood cells) along with platelet activation (building blocks for clots). Carboxyhemoglobin in the blood eventually displaces oxygen and further contributes to an ischemic and hypoxic environment in the retinal tissue. Patients who smoke tend to have elevated low-density lipoprotein (bad cholesterol) levels and decreased high-density lipoprotein (good cholesterol) levels.
8. Vasculitis-inflammation of the blood vessels.
Long-term, low-grade inflammation has been linked to the progression of DR, including increased vascular permeability, vascular occlusion, neovascularization (new leaky blood vessel growth), and retinal neurodegeneration. Aspirin use in diabetics is NOT associated with increased risk of hemorrhage, progression of retinopathy, or macular edema and may actually slow the progress of Diabetic Retinopathy. CONSULT WITH YOUR PRIMARY CARE PHYSICIAN BEFORE ADDING ASPIRIN TO YOUR TREATMENT PLAN.
9. Obesity (body mass index less than 30, better around 25)
Obese patients tend to have an increase in chemical factors (cytokines, glycerol, and other fatty acids-which are inflammatory) that lead to the increased insulin resistance and decreased insulin production causing an increase in blood glucose levels.
10. Vitamin D
Recent research suggests an association between patients with type 2 diabetes who also have a vitamin D deficiency and an increased risk of Diabetic Retinopathy. Animal studies have reported that vitamin D administration helped reduce endothelial cell inflammation and proliferation—a major cause of severe retinopathy. Further studies are required to better understand the causal relationship between vitamin D deficiency and DR in patients with type 2 diabetes.