A 52-year-old man comes to the clinic for follow-up. He has no complaints except for occasional back pain. His past medical history includes type 2 diabetes mellitus, hyperlipidemia, and chronic low back pain. He was hospitalized for pyelonephritis one year ago. He does not smoke and he consumes alcohol on weekends. He denies any illegal drug use. His current medications are metformin, glyburide, and simvastatin. His blood pressure is 125/76 mmHg and his heart rate is 89/min. His BMI is 34 kg/m2. There are no carotid bruits. Peripheral pulses are full on both sides. Laboratory values are the following:
Hemoglobin 14.2 mg/dl Creatinine 0.8 mg/dl HbA1c 8.5% LDL cholesterol 112 mg/dl Urine protein trace
Ophthalmologic evaluation 3 months ago showed mild non-proliferative retinopathy. Which of the following is the best next step in preventing further retinal damage in this patient?
- A. Increase the dose of simvastatin [7%1 .,
- B. Initiate insulin therapy [63% 1
- C. Refer for panretinal photocoagulation [1 0%1
- D. Start an angiotensin converting enzyme inhib [1 3%1
- E. Start aspirin [6% 1
Explanation: User ld:
Routine ophthalmologic evaluation is crucial for patients with diabetes since the changes of diabetic retinopathy are usually asymptomatic until they become severe and irreversible. Nonproliferative retinopathy appears as cotton-wool spots, intraretinal hemorrhages, microvascular changes, and hard exudates without the presence of neovascularity. Fortunately this patient currently has only mild nonproliferative retinopathy, but he is still at risk for progressing to macular edema and proliferative retinopathy since his HbA 1c is above the typical goal of 6.5%. Strict glycemic control is the key to preventing progression of diabetic retinopathy. Since this patient has been unable to meet his HbA 1c goal on a two-drug regimen of metformin and glyburide, changing to insulin should be considered at this time. Note that there is a phenomenon of transient worsening of diabetic retinopathy when aggressive insulin therapy is first instituted so close ophthalmologic monitoring is warranted.
(Choice A) Stalin medications have been proven to prevent heart disease, but the benefits of stalin medications as they pertain to preventing diabetic retinopathy are unclear.
(Choice C) Panretinal photocoagulation is only used in the treatment of severe proliferative diabetic retinopathy.
(Choice D) Control of hypertension does help to delay the progression of diabetic retinopathy. However, this patient is not hypertensive and there is no evidence that ACE inhibitors prevent progression of diabetic retinopathy in normotensive patients.
(Choice E) Studies have failed to show a benefit of aspirin for preventing diabetic retinopathy.
Educational objective: Diabetic patients should receive frequent ophthalmologic evaluations for diabetic retinopathy since the problem is usually asymptomatic until the damage is severe. Aggressive glucose control is the best treatment in patients who have mild disease with nonproliferative changes, whereas panretinal photocoagulation is reserved for patients with severe proliferative retinopathy.