7.6 Symptoms and Onset
All patients with diabetes are at risk for DME, and it can develop at any stage of diabetic retinopathy. Onset of DME is usually insidious and without pain. Early stages may be asymptomatic. The defining feature of DME is edema of the retina, and it manifests with blurring of central visual acuity. Fluid in the macular area tends to coalesce in the central avascular fovea, resulting in reduced vision. The more fluid accumulates in and under the retina, the worse the visual acuity becomes, and severity of vision loss can range from mild to profound.