Diabetic Retinopathy (Exam #5)

Diagnostic test results

1. Dilated eye exam looking for presence or absence of a cataract, abnormal blood vessels, swelling, blood or fatty deposits in the retina, growth of new blood vessels and scar tissue, bleeding in the vitreous, retinal detachment, abnormalities in the optic nerve. 2. Fluorescein angiography- An eye test that uses a special dye and camera to look at blood flow in the retina and choroid, the two layers in the back of the eye. 3. Optical coherence tomography- is a non-invasive imaging test that uses light waves to take cross- section pictures of your retina, the light sensitive tissue lining the back of the eye.

S/S

1. Mild blurriness 2. Distant vision 3. Flashes and floaters 4. Sudden loss of vision, If left untreated it can cause severe vision loss and/or blindness.

Etiology

1. NPDR: small blood vessels within the retina are damaged, fluid and blood are leaked, causes retina to swell and leads to blurred vision. 2. PDR: new and fragile blood vessels grow abnormally from the retina into the vitreous, bleeding, scarring, contraction of vitreous.

Intravitreal injections of anti-VEGF agents

Are used to reduce active neovascularization and vitreous hemorrhage.

Overview of treatment

Eye surgeons cannot reverse the damage caused by diabetic retinopathy but if caught in time modern treatment methods can slow its progression and prevent further vision loss. It is critical for patients with DM to have eye exams regularly even if they have not yet noticed symptoms. If someone with DM notices any changes in their vision they should contact their doctor immediately. 1. Careful control of blood glucose levels may slow the onset and progression, control BP, Lipid control, A1C control. 2. Intensive management of hypertension and hyperlipidemia (high lipid levels...high LDL) 3. Photocoagulation using an argon laser provides the major direct treatment modality for diabetic retinopathy. Laser photocoagulation applied directly to leaking micro aneurysms and grid photocoagulation with a checkerboard pattern of laser burns applied to diffuse areas of leakage and thickening. 4. Intravitreal injections of anti-VEGF agents 5. Vitrectomy

Diabetic Retinopathy

Is a complication of diabetes that affects the eyes. It is caused by damage to the blood vessels of the light sensitive tissue at the back of the eye (retina). Blood flow to retina is inadequate. It is part of the triopathy and it is intimal thickening and it is spots bleeding. Diabetes is the leading cause of acquired blindness in the U.S. Retinopathy of DM is associated with retinal aneurysms and Hemorrhage. 2 types: Background or Nonproliferative retinopathy (NPDR) & Proliferative Diabetic Retinopathy (PDR)

Background or Nonproliferative retinopathy (NPDR)

It involves the engorgment of the retinal veins, thickening of the capillary endothelial basement membrane, and development of capillary micro aneurysms. Small intraretinal hemorrhages may develop and micro infarcts may cause cotton-wool spots and leakage of exudates. A sensation of glare (b/c of scattering of light) is a common complaint. The most common cause of decreased vision in persons with background retinopathy is macular edema. The edema is caused primarily by the breakdown of the blood-retina barrier at the level of the capillary endothelium, allowing leakage of fluid and plasma constituents into the surrounding retina.

Proliferative Diabetic Retinopathy (PDR)

It is characterized by the formation of new, fragile blood vessels (neovascularization) at the optic disk and elsewhere in the retina. These vessels grow in front of the retina along the posterior surface of the vitreous or into the vitreous. They threaten vision in two ways: 1. b/c they are abnormal, they often bleed easily, leaking blood into the vitreous cavity and decreasing visual acuity. 2. The blood vessels attach firmly to the retinal surface and posterior surface of the vitreous, such that normal movement of the vitreous may exert a pull on the retina, causing retinal detachment and progressive blindness. It is the most common sight- threatening lesion is T1DM. Early PDR is likely to be asymptomatic, it must be identified early before bleeding occurs and obscures the view of the fundus or leads to fibrous and retinal detachment.

Vitrectomy

May be used for removing vitreous hemorrhage and severing vitreoretinal membranes that develop.

High risk groups

People with diabetes 1. Poor glycemic control 2. Abnormal lipids are a risk= high LDL, low HDL, and high total cholesterol 3. The length of time a person has DM 4. Chronic hyperglycemia, hypertension, hypercholestremia ( high cholesterol) & smoking 5. T1DM (insulin dependent)- do not develop retinopathy for at least 3-5 years after the onset of disease 6. T2DM (non-insulin dependent)- may have retinopathy at the time of diagnosis (may be a presenting symptom),