Editing Diabetic retinopathy (section)

==Management==
There are four common treatments for diabetic retinopathy: [[anti-VEGF]] injections, [[steroid]] injections, panretinal [[laser photocoagulation]], and [[vitrectomy]].<ref>{{cite journal | vauthors = Martinez-Zapata MJ, Salvador I, Martí-Carvajal AJ, Pijoan JI, Cordero JA, Ponomarev D, Kernohan A, Solà I, Virgili G | title = Anti-vascular endothelial growth factor for proliferative diabetic retinopathy | journal = The Cochrane Database of Systematic Reviews | volume = 2023 | issue = 3 | pages = CD008721 | date = March 2023 | pmid = 36939655 | pmc = 10026605 | doi = 10.1002/14651858.CD008721.pub3 }}</ref> Current treatment regimens can prevent 90% of severe vision loss.{{sfn|Flaxel|Adelman|Bailey|Fawzi|2020|loc="Early detection of diabetic retinopathy"}}

Although these treatments are very successful (in slowing or stopping further vision loss), they do not cure diabetic retinopathy. Caution should be exercised in treatment with laser surgery since it causes a loss of retinal tissue. It is often more prudent to inject triamcinolone or anti-VEGF drugs. In some patients it results in a marked increase of vision, especially if there is an [[macular edema|edema of the macula]].<ref name=":0">{{cite journal | vauthors = Mitchell P, Wong TY | title = Management paradigms for diabetic macular edema | journal = American Journal of Ophthalmology | volume = 157 | issue = 3 | pages = 505–13.e1–8 | date = March 2014 | pmid = 24269850 | doi = 10.1016/j.ajo.2013.11.012 }}</ref>

In addition, standard treatment for diabetic retinopathy includes improving control of blood sugar, blood pressure, and blood cholesterol, all of which can reduce diabetic retinopathy progression.{{sfn|Lin|Hsih|Lin|Wen|2021|loc="Treatments"}}

===Mild or moderate NPDR===
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 | vauthors = Ngah NF, Muhamad NA, Abdul Aziz RA, Mohamed SO, Ahmad Tarmizi NA, Adnan A, Asnir ZZ, Hussein Z, Siew HF, Mohamed M, Lodz NA, Valayatham V | 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 | date = 2022-12-18 | pmid = 36536974 | pmc = 9729076 | doi = 10.18240/ijo.2022.12.16 }}</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>

===Diabetic macular edema===
Those at highest risk of vision loss – that is, with edema near the center of the macula – benefit most from eye injections of [[anti-VEGF]] therapies [[aflibercept]], [[bevacizumab]], or [[ranibizumab]].{{sfn|Flaxel|Adelman|Bailey|Fawzi|2020|loc="Anti-Vascular Endothelial Growth Factor Therapy"}} There is no widely accepted dosing schedule, though people typically receive more frequent injections during the first year of treatment, with less frequent injections in subsequent years sufficient to maintain remission.{{sfn|Lin|Hsih|Lin|Wen|2021|loc="Treatments"}} Those whose eyes don't improve with anti-VEGF therapy may instead receive laser photocoagulation, typically in the form of short laser pulses.{{sfn|Kuroiwa|Malerbi|Regatieri|2021|loc="Laser"}}
Those with macular edema but no vision loss do not benefit from treatment; the American Academy of Ophthalmology recommends deferring treatment until visual acuity falls to at least 20/30.{{sfn|Flaxel|Adelman|Bailey|Fawzi|2020|loc="Treatment Deferral"}} The diabetic macular edema manifestation is difficult to predict. Autoantibodies against [[hexokinase 1]] are commonly associated with diabetic macular edema manifestation. Nearly one-third of patients with diabetic macular edema were found to be positive for anti-hexokinase 1 autoantibodies. Importantly, these autoantibodies were rare in patients with diabetic retinopathy only or diabetes mellitus only. However, these autoantibodies fail to predict disease onset. They likely manifest secondary to the tissue-damaging stimulus at diabetic macular edema onset and cannot be used to predict diabetic macular edema before its onset.<ref name="Simcikova et al. 2024">{{cite journal | vauthors = Šimčíková D, Ivančinová J, Veith M, Dusová J, Matušková V, Němčanský J, Kunčický P, Chrapek O, Jirásková N, Gojda J, Heneberg P | title = Serum autoantibodies against hexokinase 1 manifest secondary to diabetic macular edema onset | journal = Diabetes Research and Clinical Practice | volume = 212 | issue = 1 | pages = 111721 | date = June 2024 | pmid = 38821414 | doi = 10.1016/j.diabres.2024.111721 }}</ref>

===Laser photocoagulation===
[[File:Fundus photo showing scatter laser surgery for diabetic retinopathy EDA09.JPG|thumb|Image of [[Fundus (eye)|fundus]] showing scatter [[Laser coagulation|laser surgery]] for diabetic retinopathy]]

[[Laser photocoagulation]] can be used in two scenarios for the treatment of diabetic retinopathy. Firstly, to treat macular edema<ref>{{cite journal | vauthors = Jorge EC, Jorge EN, Botelho M, Farat JG, Virgili G, El Dib R | title = Monotherapy laser photocoagulation for diabetic macular oedema | journal = The Cochrane Database of Systematic Reviews | volume = 2018 | issue = 10 | pages = CD010859 | date = October 2018 | pmid = 30320466 | pmc = 6516994 | doi = 10.1002/14651858.CD010859.pub2 | collaboration = Cochrane Eyes and Vision Group }}</ref> and secondly, for treating whole retina (panretinal photocoagulation) for controlling neovascularization. It is widely used for early stages of proliferative retinopathy. There are different types of lasers and there is evidence available on their benefits to treat proliferative diabetic retinopathy.<ref>{{cite journal | vauthors = Moutray T, Evans JR, Lois N, Armstrong DJ, Peto T, Azuara-Blanco A | title = Different lasers and techniques for proliferative diabetic retinopathy | journal = The Cochrane Database of Systematic Reviews | volume = 2018 | issue = 3 | pages = CD012314 | date = March 2018 | pmid = 29543992 | pmc = 6494342 | doi = 10.1002/14651858.cd012314.pub2 }}</ref>

====Panretinal laser photocoagulation====
For those with proliferative or severe non-proliferative diabetic retinopathy, vision loss can be prevented by treatment with panretinal laser photocoagulation.{{sfn|Lin|Hsih|Lin|Wen|2021|loc="Treatments"}}

The goal is to create 1,600–2,000 burns in the retina with the hope of reducing the retina's oxygen demand, and hence the possibility of [[ischemia]]. It is done in multiple sittings.

In treating advanced diabetic retinopathy, the burns are used to destroy the abnormal new blood vessels that form in the retina. This has been shown to reduce the risk of severe vision loss for eyes at risk by 50%.<ref name=kertes2007>{{Cite book|veditors=Kertes PJ, Johnson TM |title=Evidence Based Eye Care |year=2007 |isbn=978-0-7817-6964-8 |publisher=Lippincott Williams & Wilkins |location=Philadelphia, PA}}{{Page needed|date=September 2010}}</ref>

Before using the laser, the ophthalmologist dilates the pupil and applies [[anaesthetic]] drops to numb the eye. In some cases, the doctor also may numb the area behind the eye to reduce discomfort. The patient sits facing the laser machine while the doctor holds a special lens on the eye. The physician can use a single spot laser, a pattern scan laser for two dimensional patterns such as squares, rings and arcs, or a navigated laser which works by tracking retinal eye movements in real time.<ref>{{cite journal | vauthors = Amoroso F, Pedinielli A, Astroz P, Semoun O, Capuano V, Miere A, Souied EH | title = Comparison of pain experience and time required for pre-planned navigated peripheral laser versus conventional multispot laser in the treatment of diabetic retinopathy | journal = Acta Diabetologica | volume = 57 | issue = 5 | pages = 535–541 | date = May 2020 | pmid = 31749047 | doi = 10.1007/s00592-019-01455-x | s2cid = 208172191 }}</ref><ref>{{cite journal | vauthors = Chhablani J, Mathai A, Rani P, Gupta V, Arevalo JF, Kozak I | title = Comparison of conventional pattern and novel navigated panretinal photocoagulation in proliferative diabetic retinopathy | journal = Investigative Ophthalmology & Visual Science | volume = 55 | issue = 6 | pages = 3432–3438 | date = May 2014 | pmid = 24787564 | doi = 10.1167/iovs.14-13936 | doi-access =  }}</ref> During the procedure, the patient will see flashes of light. These flashes often create an uncomfortable stinging sensation for the patient. After the laser treatment, patients should be advised not to drive for a few hours while the pupils are still dilated. Vision will most likely remain blurry for the rest of the day. Though there should not be much pain in the eye itself, an [[ice-cream headache]] like pain may last for hours afterwards.

Patients will lose some of their peripheral vision after this surgery although it may be barely noticeable by the patient. The procedure does however save the center of the patient's sight. Laser surgery may also slightly reduce colour and night vision.

A person with proliferative retinopathy will always be at risk for new bleeding, as well as [[glaucoma]], a complication from the new blood vessels. This means that multiple treatments may be required to protect vision.

===Medications===
====Intravitreal triamcinolone acetonide====
[[Triamcinolone]] is a long acting steroid preparation. Treating people with DME with intravitreal injections of triamcinolone may lead to a some degree of improvement in visual acuity when compared to eyes treated with placebo injections.<ref name=":3">{{cite journal | vauthors = Rittiphairoj T, Mir TA, Li T, Virgili G | title = Intravitreal steroids for macular edema in diabetes | journal = The Cochrane Database of Systematic Reviews | volume = 2020 | issue = 11 | pages = CD005656 | date = November 2020 | pmid = 33206392 | pmc = 8095060 | doi = 10.1002/14651858.CD005656.pub3 }}</ref> When injected in the vitreous cavity, the steroid decreases the macular edema (thickening of the retina at the macula) caused due to diabetic maculopathy, and that may result in an increase in visual acuity. The effect of triamcinolone is not permanent and may last up to three months, which necessitates repeated injections for maintaining the beneficial effect. Best results of intravitreal Triamcinolone have been found in eyes that have already undergone [[cataract]] surgery. Complications of intravitreal injection of triamcinolone may include cataract, steroid-induced glaucoma, and endophthalmitis.<ref name=":3" />

====Intravitreal anti-VEGF====

[[Aflibercept]] may have advantages in improving visual outcomes over bevacizumab and [[ranibizumab]], after one year, longer term advantages are unclear <ref>{{cite journal | vauthors = Virgili G, Curran K, Lucenteforte E, Peto T, Parravano M | title = Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis | journal = The Cochrane Database of Systematic Reviews | volume = 2023 | issue = 6 | pages = CD007419 | date = June 2023 | pmid = 38275741 | pmc = 10294542 | doi = 10.1002/14651858.CD007419.pub7 | collaboration = Cochrane Eyes and Vision Group }}</ref> In cases with vitreous hemorrhage, however, anti-VEGF injections proved to be less effective in restoring visual acuity than vitrectomy combined with panretinal laser-photocoagulation.<ref>{{cite journal | vauthors = Antoszyk AN, Glassman AR, Beaulieu WT, Jampol LM, Jhaveri CD, Punjabi OS, Salehi-Had H, Wells JA, Maguire MG, Stockdale CR, Martin DF, Sun JK | title = Effect of Intravitreous Aflibercept vs Vitrectomy With Panretinal Photocoagulation on Visual Acuity in Patients With Vitreous Hemorrhage From Proliferative Diabetic Retinopathy: A Randomized Clinical Trial | journal = JAMA | volume = 324 | issue = 23 | pages = 2383–2395 | date = December 2020 | pmid = 33320223 | pmc = 7739132 | doi = 10.1001/jama.2020.23027 }}</ref>

==== Other ====
[[Fenofibrate]], a drug that is also used to reduce cholesterol levels, has been studied for its role in helping to improve the negative effects caused by diabetes and reducing the occurrence of retinal inflammation.<ref name=":7" /> There is some evidence that overall, in people with type II diabetes, fenofibrate may not make a clinically significant difference in progression of DME.<ref name=":7" /> For people who have type II diabetes and have overt retinopathy, there is evidence that fenofibrate may be more effective at reducing the progression of retinal damage.<ref name=":7" />

===Surgery===
Instead of laser surgery, some people require a [[vitrectomy]] to restore vision. A vitrectomy is performed when there is a lot of blood in the [[vitreous humour|vitreous]]. It involves removing the cloudy vitreous and replacing it with a saline solution.

Studies show that people who have a vitrectomy soon after a large hemorrhage are more likely to protect their vision than someone who waits to have the operation. Early vitrectomy is especially effective in people with insulin-dependent diabetes, who may be at greater risk of blindness from a hemorrhage into the eye.

Vitrectomy may be done under general or [[local anesthesia]]. The doctor makes a tiny incision in the [[sclera]], or white of the eye. Next, a small instrument is placed into the eye to remove the vitreous and insert the saline solution into the eye.

Patients may be able to return home soon after the vitrectomy, or may be asked to stay in the [[hospital]] overnight. After the operation, the eye will be [[red]] and sensitive, and patients usually need to wear an eyepatch for a few days or weeks to protect the eye. Medicated eye drops are also prescribed to protect against [[infection]]. There is evidence which suggests anti-[[VEGF]] drugs given either prior to or during vitrectomy may reduce the risk of posterior vitreous cavity haemorrhage .<ref>{{cite journal | vauthors = Dervenis P, Dervenis N, Smith JM, Steel DH | title = Anti-vascular endothelial growth factors in combination with vitrectomy for complications of proliferative diabetic retinopathy | journal = The Cochrane Database of Systematic Reviews | volume = 2023 | issue = 5 | pages = CD008214 | date = May 2023 | pmid = 37260074 | pmc = 10230853 | doi = 10.1002/14651858.CD008214.pub4 }}</ref> Vitrectomy is frequently combined with other modalities of treatment.