macular edema

This is when fluid leaks into the center of the macula, the part of the eye that allows for central vision. Central vision is the sharp, straight-ahead vision needed to see fine detail. When fluid leaks into the macula, it causes swelling and blurs vision. Macular edema can happen at any stage of diabetic retinopathy, although it is more likely to happen as the disease worsens. About half of the people with proliferative retinopathy also have macular edema.