Proleferative<unk>  Emptied retinal venules due to arterial branch occlusion in<unk>  (fluorescein angiography)<unk>  often has no early warning signs. Even macular edema, which can cause rapid central vision loss, may not have any warning signs for some time. In general, however, a person with macular edema is likely to have blurred vision, making it hard to do things like read or<unk> ive. In some cases, the vision will get better or worse during the day. The first stage, called non-proliferative<unk>  (NPDR), has no symptoms. Patients may not notice the signs and have 20/20 vision. The only way to detect NPDR is by fundus examination by direct or indirect ophthalmoscope by a trained ophthalmologist or optometrist, fundus photography can be used for objective documentation of the fundus findings, in which microaneurysms (microscopic blood-filled bulges in the artery walls) can be seen. If there is reduced vision, fluorescein angiography can show narrowing or blocked retinal blood vessels clearly (lack of blood flow or retinal ischemia). Macular edema, in which blood vessels leak their contents into the macular region, can occur at any stage of NPDR. Its symptoms are blurred vision and darkened or distorted images that are not the same in both eyes. Ten percent (10%) of<unk>  patients will have vision loss related to macular edema. Optical Coherence Tomography can show areas of retinal thickening due to fluid accumulation from macular edema. In the second stage, abnormal new blood vessels (neovascularisation) form at the back of the eye as part of proliferative<unk>  (PDR); these can burst and bleed (vitreous hemorrhage) and blur the vision, because these new blood vessels are fragile. The first time this bleeding occurs, it may not be very severe. In most cases, it will leave just a few specks of blood, or spots floating in a person's visual field which may last for months. These spots are often followed within a few days or weeks by a much greater leakage of blood, which blurs the vision. In extreme cases, a person may only be able to tell light from dark in that eye. It may take the blood anywhere from a few days to months or even years to clear from the inside of the eye, and in some cases the blood will not clear. These types of large hemorrhages tend to happen more than once. On funduscopic exam, a doctor will see cotton wool spots, flame hemorrhages, and dot-blot hemorrhages.
Diabetic retinopathy
Autoimmune retinopathy
Hypertensive retinopathy
Radiation retinopathy
Photic retinopathy
Retinal vasculitis
Autoimmune optic neuropathy
Sickle cell retinopathy