Original Article: http://www.mayoclinic.com/health/medical/IM02507
In the early stages of diabetic retinopathy, the walls of the blood vessels in your retina weaken. Tiny bulges protrude from the vessel walls, sometimes leaking or oozing fluid and blood into the retina. Nerve fibers in the retina may swell, producing white spots in the retina. As diabetic retinopathy progresses, new blood vessels may grow and threaten your vision.