Editing Diabetic retinopathy (section)

==Diagnosis and classification==
Diabetic retinopathy is typically diagnosed by [[retinal exam]] observations using [[ophthalmoscopy]].{{sfn|Lim|2019|loc="Diagnosis and ancillary testing"}} The [[American Academy of Ophthalmology]] divides diabetic retinopathy into five categories of progressive severity. The first category, "no apparent retinopathy", describes those with a healthy retinal exam.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}} The next three categories: mild, moderate, and severe nonproliferative diabetic retinopathy (NPDR) describe increasing levels of damage to the retina. People with mild NPDR have [[microaneurysm]]s in the retina, but no other damage. Those with severe NPDR have 20+ [[retinal hemorrhage]]s in each quadrant of the retina, a distinctive pattern of damage on the veins of the retina called "venous beading" in at least two retinal quadrants, and obvious [[intraretinal microvascular abnormalities]] anywhere on the retina. Moderate NPDR is defined as more severe than mild NPDR, but not yet meeting the criteria for severe NPDR.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}} The fifth stage, proliferative diabetic retinopathy, is for those with new blood vessels forming throughout the retina ("retinal [[neovascularization]]"), or blood leaking into the [[vitreous humor]] ("[[vitreous hemorrhage]]") or between the [[vitreous membrane]] and retina ("[[preretinal hemorrhage]]").{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}}

The same guidelines separately divide macular edema into two categories: "macular edema apparently absent" and "macular edema apparently present". The latter is further subdivided into "mild"—retinal thickening or lipid deposits far from the macula's center; "moderate"— thickening or deposits near the center; and "severe"—thickening or deposits on the macula center.{{sfn|Brownlee|Aiello|Sun|Cooper|2020|loc="Clinical features of diabetic retinopathy"}} [[Optical coherence tomography]] is frequently used to assess macular edema.{{sfn|Lim|2019|loc="Diagnosis and ancillary testing"}}

[[Fluorescein angiography]] is used by retina specialists to further assess diabetic retinopathy severity and to determine sites of macular damage.{{sfn|Lim|2019|loc="Diagnosis and ancillary testing"}}{{sfn|Aiello|Silva|Cavallerano|Klein|2016|loc="Detection"}}

===Screening===
Due to the lack of symptoms, most people with diabetic retinopathy are unaware that they have the condition until they visit an eye doctor.{{sfn|Lim|2019|loc="Epidemiology"}} Both the [[American Diabetes Association]] (ADA) and the [[International Council of Ophthalmology]]  (ICO) recommend regular eye exams for those with diabetes to screen for diabetic retinopathy (except those with [[gestational diabetes]]).{{sfn|Vujosevic|Aldington|Silva|Hernández|2020|loc="Screening for diabetic retinopathy: who, when, and how"}} The ADA recommends a comprehensive eye examination at the time of type 2 diabetes diagnosis, and within five years of the onset of type 1 diabetes. For women with diabetes who become pregnant, the ADA recommends an eye examination before pregnancy, in each trimester, and for a year post partum.{{sfn|Vujosevic|Aldington|Silva|Hernández|2020|loc="Screening for diabetic retinopathy: who, when, and how"}} The ICO recommends eye examinations for those with diabetes include a [[visual acuity]] examination and a [[Eye examination#Retinal examination|retinal examination]] via [[ophthalmoscopy]] or [[retinal photography]].{{sfn|Vujosevic|Aldington|Silva|Hernández|2020|loc="Screening for diabetic retinopathy: who, when, and how"}}

Iceland, Ireland, and the United Kingdom are the only countries with full national diabetic retinopathy screening programs, while substantial regional screening programs have been implemented in parts of mainland Europe, parts of Asia, and Botswana.{{sfn|Vujosevic|Aldington|Silva|Hernández|2020|loc="Development of nationwide screening programs"}} In the UK, screening for diabetic retinopathy is part of the standard of care for people with diabetes.<ref>{{cite web|title=Diabetic eye screening – NHS Choices|url=http://www.nhs.uk/Conditions/diabetic-eye-screening/Pages/Introduction.aspx|publisher=NHS Choices|date=12 July 2016}}</ref> After one normal screening in people with diabetes, further screening is recommended every year.<ref>{{Cite web | url=https://www.nhs.uk/conditions/diabetic-eye-screening/#when-diabetic-eye-screening-is-offered | title=Diabetic eye screening| date=2017-10-18}}</ref> [[Teleophthalmology]] has been employed in these programs.<ref>{{cite journal | vauthors = Gupta A, Cavallerano J, Sun JK, Silva PS | title = Evidence for Telemedicine for Diabetic Retinal Disease | journal = Seminars in Ophthalmology | volume = 32 | issue = 1 | pages = 22–28 | date = 17 October 2016 | pmid = 27748634 | doi = 10.1080/08820538.2016.1228403 | s2cid = 1335693 }}</ref>