Editing Glaucoma (section)

==Risk factors==
Glaucoma can affect anyone. Some people have a higher risk or susceptibility to develop glaucoma due to certain [[Risk factor (epidemiology)|risk factor]]s, including increasing age, high intraocular pressure, a family history of glaucoma, and use of steroid medications.<ref name="NIH2016Fact" /> 

=== Ocular hypertension ===
[[Ocular hypertension]] (increased pressure within the eye) is an important risk factor for glaucoma, but only about 10-70% of people - depending on ethnic group - with primary open-angle glaucoma actually have elevated ocular pressure.<ref name="pmid26886116">{{cite journal| author=Kim KE, Park KH| title=Update on the Prevalence, Etiology, Diagnosis, and Monitoring of Normal-Tension Glaucoma. | journal=Asia Pac J Ophthalmol (Phila) | year= 2016 | volume= 5 | issue= 1 | pages= 23–31 | pmid=26886116 | doi=10.1097/APO.0000000000000177 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26886116  }}, (review) (open access).</ref> Ocular hypertension&mdash;an intraocular pressure above the traditional threshold of {{cvt|21|mmHg|hPa}} or even above {{cvt|24|mmHg|hPa}}&mdash;is not necessarily a pathological condition, but it increases the risk of developing glaucoma. 

A study with 1636 persons aged 40-80 who had an intraocular pressure above 24{{nbsp}}mmHg in at least one eye, but no indications of eye damages, showed that after five years, 9.5% of the untreated participants and 4.4% of the treated participants had developed glaucomatous symptoms, meaning that only about one in 10 untreated people with elevated intraocular pressure will develop glaucomatous symptoms over that period of time.<ref name="pmid29501371" /> Given these results, the clinical decision to treat everyone with elevated intraocular pressure with glaucoma therapy as a preventative measure is a matter of debate.<ref name="pmid29501371" /> As of 2018, most ophthalmologists favored treatment of those with additional risk factors.<ref name="pmid29501371">{{cite journal| author=Gordon MO, Kass MA| title=What We Have Learned From the Ocular Hypertension Treatment Study. | journal=Am J Ophthalmol | year= 2018 | volume= 189 | issue=  | pages= xxiv-xxvii | pmid=29501371 | doi=10.1016/j.ajo.2018.02.016 | pmc=5915899 }} </ref>

For eye pressures, a value of {{cvt|21|mmHg|hPa|disp=flip}} above [[atmospheric pressure]] {{cvt|760|mmHg|hPa|disp=flip}} is often used, with higher pressures leading to a greater risk.<ref name="Man2015" /><ref>{{cite book |url=https://books.google.com/books?id=vbWWuX1dgjYC&pg=PA180 |title=Glaucoma |vauthors=Rhee DJ |date=2012 |publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins |isbn=978-1-60913-337-5 |edition=2nd |location=Philadelphia |page=180 |oclc=744299538}}</ref> However, some may have high eye pressure for years and never develop damage.<ref name="Man2015" /> Conversely, optic nerve damage may occur with normal pressure, known as normal-tension glaucoma.<ref>{{cite journal |vauthors=Mi XS, Yuan TF, So KF |date=16 September 2014 |title=The current research status of normal tension glaucoma |journal=Clinical Interventions in Aging |volume=9 |pages=1563–1571 |doi=10.2147/CIA.S67263 |pmc=4172068 |pmid=25258525 |doi-access=free}}</ref> In case of above-normal intraocular pressure, the mechanism of open-angle glaucoma is believed to be the impeded exit of aqueous humor through the trabecular meshwork, while in closed-angle glaucoma, the [[iris (anatomy)|iris]] blocks the trabecular meshwork.<ref name="Man2015" /> Diagnosis is achieved by performing an [[eye examination]].<ref name="NIH2016Fact" /> Often, the optic nerve shows an abnormal amount of [[optic cup (anatomical)|cupping]].<ref name="Man2015" />

===Family history and genetics===
Positive family history is a risk factor for glaucoma. The relative risk of having primary open-angle glaucoma is increased about two- to four-fold for people who have a sibling with glaucoma.<ref name=yanoff>{{cite book| vauthors = Yanoff M, Duker JS |title=Ophthalmology|year=2009|publisher=Mosby Elsevier|isbn=978-0-323-04332-8|page=1096|edition=3rd}}</ref> Glaucoma, particularly primary open-angle glaucoma, is associated with [[mutation]]s in several [[gene]]s, including ''[[MYOC]], ASB10, [[WDR36]], [[Neurotrophin-4|NTF4]]'', ''[[TANK-binding kinase 1|TBK1]]'',<ref name="OMIM137760">{{OMIM|137760|Glaucoma, Primary Open Angle; POAG}}</ref> and ''[[RPGRIP1]].''<ref>{{cite journal | vauthors = Fernández-Martínez L, Letteboer S, Mardin CY, Weisschuh N, Gramer E, Weber BH, Rautenstrauss B, Ferreira PA, Kruse FE, Reis A, Roepman R, Pasutto F | display-authors = 6 | title = Evidence for RPGRIP1 gene as risk factor for primary open angle glaucoma | journal = European Journal of Human Genetics | volume = 19 | issue = 4 | pages = 445–451 | date = April 2011 | pmid = 21224891 | pmc = 3060327 | doi = 10.1038/ejhg.2010.217 }}</ref> Many of these genes are involved in critical cellular processes that are implicated in the development and progression of glaucoma, including regulation of intraocular pressure, retinal ganglion cell health, and optic nerve function.<ref name="pmid28505344">{{cite journal| author=Wiggs JL, Pasquale LR| title=Genetics of glaucoma. | journal=Hum Mol Genet | year= 2017 | volume= 26 | issue= R1 | pages= R21–R27 | pmid=28505344 | doi=10.1093/hmg/ddx184 | pmc=6074793 }} </ref> Normal-tension glaucoma, which comprises 30-90% of primary open-angle glaucoma (depending on ethnic group),<ref name="pmid26886116">{{cite journal| author=Kim KE, Park KH| title=Update on the Prevalence, Etiology, Diagnosis, and Monitoring of Normal-Tension Glaucoma. | journal=Asia Pac J Ophthalmol (Phila) | year= 2016 | volume= 5 | issue= 1 | pages= 23–31 | pmid=26886116 | doi=10.1097/APO.0000000000000177 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26886116  }}, (review) (open access).</ref> is also associated with genetic mutations (including ''[[OPA1]]'' and ''[[Optineurin|OPTN]]'' genes).<ref>{{OMIM|606657|Glaucoma, Normal Tension, Susceptibility to}}</ref>

Additionally, some rare genetic conditions increase the risk of glaucoma, such as [[Axenfeld–Rieger syndrome|Axenfeld-Rieger syndrome]] and [[primary congenital glaucoma]], which is  associated with mutations in ''[[CYP1B1]]'' or ''[[LTBP2]].''<ref name=":5">{{Cite journal |last1=Badawi |first1=Abdulrahman H. |last2=Al-Muhaylib |first2=Ahmed A. |last3=Al Owaifeer |first3=Adi Mohammed |last4=Al-Essa |first4=Rakan S. |last5=Al-Shahwan |first5=Sami A. |date=2019-10-01 |title=Primary congenital glaucoma: An updated review |journal=Saudi Journal of Ophthalmology |volume=33 |issue=4 |pages=382–388 |doi=10.1016/j.sjopt.2019.10.002 |pmid=31920449 |pmc=6950954 |issn=1319-4534}}</ref> They are inherited in an autosomal recessive fashion.<ref name=":5" /> Axenfeld-Rieger syndrome is inherited in an autosomal dominant fashion and is associated with ''[[PITX2]]'' or [[Forkhead box C1|''FOXC1'']].<ref>{{Citation |last1=Zamora |first1=Edgar A. |title=Axenfeld-Rieger Syndrome |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK538504/ |work=StatPearls |access-date=2023-09-22 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30860739 |last2=Salini |first2=Baby}}</ref>

===Ethnicity===
The total prevalence of glaucoma is about the same in North America and Asia, but the prevalence of angle-closure glaucoma is four times higher in Asia than in North America.<ref name="pmid24974815"/>

In the United States, glaucoma is more common in African Americans, Latinos, and Asian-Americans.<ref name="Stein 2021" />

===Other===
[[File:Arterial blood flow reversal in neovascular glaucoma.gif |thumb|600px| [[Laser Doppler imaging]] reveals arterial blood flow reversal in neovascular glaucoma. The color change of the Doppler image in the central retinal artery during the cardiac cycle indicates arterial flow reversal.<ref name=Puyo2020Reversal>{{cite arXiv | vauthors = Puyo L, Paques M, Atlan M | title = Retinal blood flow reversal in out-of-plane vessels imaged with laser Doppler holography | date = 2020 | class = physics.med-ph | eprint = 2008.09813}}</ref>]]
Other factors can cause glaucoma, known as "secondary glaucoma", including prolonged use of [[anabolic steroid|steroid]]s (steroid-induced glaucoma); conditions that severely restrict blood flow to the eye, such as severe [[diabetic retinopathy]] and [[central retinal vein occlusion]] (neovascular glaucoma); [[Blast-related ocular trauma|ocular trauma]] (angle-recession glaucoma); [[plateau iris]]; and inflammation of the middle layer of the pigmented vascular eye structure ([[uveitis]]), known as [[uveitic glaucoma]].