Diabetic retinopathy: Difference between revisions

Diabetic retinopathy is the result of damage to the small blood vessels and neurons of the retina. The earliest changes leading to diabetic retinopathy include narrowing of the retinal arteries associated with [[Ischemia|reduced retinal blood flow]]; dysfunction of the neurons of the inner retina, followed in later stages by changes in the function of the outer retina, associated with subtle changes in visual function; dysfunction of the [[blood-retinal barrier]], which protects the retina from many substances in the blood (including toxins and [[immune cells]]), leading to the leaking of blood constituents into the retinal [[neuropile]].<ref name="XuCurtisStitt">{{cite journal| vauthors = Xu H, Curtis T, Stitt A |title=Pathophysiology and Pathogenesis of Diabetic Retinopathy [internet] |journal= Diapedia|date=13 August 2013 |volume=7104343513 |issue=14 |doi=10.14496/dia.7104343513.14|doi-broken-date=2024-0209-0518 |url=http://www.diapedia.org/acute-and-chronic-complications-of-diabetes/7104343513/pathophysiology-of-diabetic-retinopathy|access-date=26 August 2016}}</ref> Later, the basement membrane of the retinal blood vessels thickens, [[capillaries]] degenerate and lose cells, particularly [[pericytes]] and vascular [[smooth muscle cells]]. This leads to loss of blood flow and progressive [[ischemia]], and microscopic [[aneurysm]]s which appear as balloon-like structures jutting out from the capillary walls, which recruit inflammatory cells; and advanced dysfunction and degeneration of the [[neurons]] and [[glia]]l cells of the retina.<ref name="XuCurtisStitt"/><ref>{{Cite journal|title=Understanding diabetic retinopathy | vauthors = Pardianto G |journal=Mimbar Ilmiah Oftalmologi Indonesia |year=2005 |volume=2 |pages=65–6}}</ref> The condition typically develops about 10–15 years after receiving the diagnosis of diabetes mellitus.

For those with mild to moderate non-proliferative diabetic retinopathy, the American Academy of Ophthalmology recommends only more frequent retinal exams—every six to twelve months—as these people are at an increased risk of developing proliferative retinopathy or macular edema.{{sfn|Flaxel|Adelman|Bailey|Fawzi|2020|loc="Mild to moderate NPDR without macular edema"}} Injection of [[anti-VEGF]] drugs or steroids can reduce diabetic retinopathy progression in around half of eyes treated; however, whether this results in improved vision long term is not yet known.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Treatment of nonproliferative diabetic retinopathy”}} The lipid-lowering drug [[fenofibrate]] also reduces progression of disease in people with mild to moderate disease.<ref>{{Cite journal |last1=Ngah |first1=Nor Fariza |last2=Muhamad |first2=Nor Asiah |last3=Abdul Aziz |first3=Roslin Azni |last4=Mohamed |first4=Shelina Oli |last5=Ahmad Tarmizi |first5=Nor Azita |last6=Adnan |first6=Azian |last7=Asnir |first7=Zalifah Zakiah |last8=Hussein |first8=Zanariah |last9=Siew |first9=Hui Foo |last10=Mohamed |first10=Masni |last11=Lodz |first11=Noor Aliza |last12=Valayatham |first12=Vijayamala |date=2022-12-18 |title=Fenofibrate for the prevention of progression of non-proliferative diabetic retinopathy: review, consensus recommendations and guidance for clinical practice |journal=International Journal of Ophthalmology |volume=15 |issue=12 |pages=2001–2008 |doi=10.18240/ijo.2022.12.16 |issn=2222-3959 |pmc=9729076 |pmid=36536974}}</ref><ref>{{Cite web |title=Trial: Fenofibrate Slows Diabetic Retinopathy Progression |url=https://www.medscape.com/viewarticle/trial-fenofibrate-slows-diabetic-retinopathy"-progression-2024a1000bm8 |access-date=2024-07-29 |website=Medscape |language=en}}</ref>