Diabetic Retinopathy

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Urgent Action

• Rapidly assess (by comprehensive eye examination with ophthalmoscopy) any patient with painless, sudden vision loss or blurry vision, which may indicate retinal/vitreous hemorrhage, retinal tear, or traction retinal detachment

• Urgent laser photocoagulation or cryopexy is indicated for treatment of proliferative diabetic retinopathy to prevent development of complications such as vitreous hemorrhage

Key Points

• Diabetic retinopathy is a vision-threatening complication of diabetes that occurs within 20 years of diagnosis in the majority of patients ¹

• Patients may present with sudden, painless vision loss; floaters; and blurry or hazy vision

• Optimal diagnosis is made through suggestive history, dilated fundus examination, and digital retinal photography

• Fluorescein angiography is useful to rule out other conditions with similar features, determine the extent of retinopathy, and guide therapy

• Primary treatment is aimed at delaying progression or onset of retinopathy by optimizing management of diabetes and comorbidities such as hypertension or hyperlipidemia. Photocoagulation and intravitreal VEGF inhibitors are reserved for some higher-risk or severe cases, especially when macular edema is present and clinically significant; vitrectomy is used only when other therapies fail or when vitreous hemorrhage or traction on macula warrant

• Complications include macular edema, vitreous hemorrhage, and retinal detachment

Pitfalls

• Underlying nonocular cancers (eg, lymphoma, multiple myeloma) or viral infection (eg, hepatitis C, cytomegalovirus) may also masquerade with findings similar to those of diabetic retinopathy and should be ruled out

• Diabetic retinopathy may coexist with ocular ischemic syndrome, so if there is unilateral or marked asymmetry of retinopathy in a patient with diabetes, evaluate for possible carotid artery occlusive disease ²

Clinical Clarification

• Diabetic retinopathy is a microvascular complication of type 1 or type 2 diabetes mellitus characterized by damage to the retinal blood vessels, resulting in progressive loss of vision caused by: 3

• Microaneurysms

• Blot hemorrhages

• Exudative, ischemic, and proliferative changes

• Macular edema

Classification

• Nonproliferative retinopathy ⁴

• Mild

• Presence of more than 1 microaneurysm

• Moderate

• Presence of more than 1 microaneurysm, hemorrhages, and hard protein exudates

• Severe

• Presence of any of the following:

• Diffuse intraretinal hemorrhage and microaneurysms in all 4 quadrants

• Venous beading in more than 2 quadrants

• Intraretinal microvascular abnormalities in more than 1 quadrant

Proliferative retinopathy 5
Characterized by neovascularization of the disk, retina, or iris
Associated with vitreous hemorrhages, gliosis, traction retinal detachment, and macular edema
Early proliferative retinopathy
Neovascularization of the optic disk in less than one-third of disk area
Neovascularization of the optic disk without preretinal or vitreous hemorrhage
Neovascularization elsewhere in less than one-half of disk area and/or without preretinal or vitreous hemorrhage
High-risk proliferative retinopathy
Neovascularization of the optic disk in one-quarter to one-third of disk area, or
Neovascularization of the optic disk and preretinal or vitreous hemorrhage, or
Neovascularization in the retina outside of the disk in at least one-half of disk area and preretinal or vitreous hemorrhage
Severe proliferative retinopathy
Preretinal or vitreous hemorrhage that obscures posterior fundus or central macular detachment
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