Editing Diabetic retinopathy (section)

==Signs and symptoms==
[[File:Fundus_Proliferative_retinopathy_EDA01.JPG|thumb|Proliferative diabetic retinopathy]]
[[File:Retinal branch occlusion ratkaj.jpg|thumb|Emptied retinal venules due to arterial branch occlusion in diabetic retinopathy (fluorescein angiography)]]

Nearly all people with diabetes develop some degree of retina damage ("retinopathy") over several decades with the disease. For many, that damage can only be detected by a [[retinal exam]], and has no noticeable effect on vision.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}} Over time, progressive retinal damage may appear on a retinal exam, first with small bulges in retinal blood vessels called [[microaneurysm]]s. Then larger abnormalities in retinal vessels: [[cotton wool spots]], [[hemorrhage]]s, lipid deposits called "hard exudates", [[intraretinal microvascular abnormalities]], and abnormal-looking retinal veins.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}} Eventually, many progress to a stage where new blood vessels grow throughout the retina. These new blood vessels often break and bleed. Minor bleeding can cause dark [[Floater|floating spots]] obstructing vision; major bleeding can completely block vision.<ref name=CDC/>

Around half of people with diabetic retinopathy develop swelling of the [[macula]], called [[macular edema]], which can begin at any time.<ref name=CDC>{{cite web|url=https://www.cdc.gov/diabetes/managing/diabetes-vision-loss.html |access-date=20 October 2022 |title=Vision Loss |publisher=Centers for Disease Control and Prevention |date=7 May 2021}}</ref> If the swelling occurs near the [[Fovea centralis|center of the macula]], it can cause vision disruptions ranging from mildly blurred vision to severe loss of the center of an affected person's visual field.<ref name=":6">{{cite web|url=https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/macular-edema |access-date=28 October 2022 |title=Macular Edema |publisher=National Eye Institute |date=5 August 2022}}</ref> Left untreated, around 30% of those with such swelling experience vision disruption over the next 3–5 years.{{sfn|Aiello|Silva|Cavallerano|Klein|2016|loc="Diabetic macular edema, ischemia, and traction"}} Macular edema is the most common cause of vision loss in people with diabetic retinopathy.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}}

The repeated processes of blood vessel growth, swelling, and scarring can eventually cause [[retinal detachment]], which manifests as the sudden appearance of dark floating spots, flashes of light, or blurred vision.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Pathophysiology of diabetic retinopathy"}}<ref>{{cite web|url=https://www.diabetes.co.uk/diabetes-complications/retinal-detachment.html |access-date=28 October 2022 |title=Retinal Detachment |publisher=Diabetes.co.uk |date=10 June 2022}}</ref>