Editing Keratoconus (section)

{{Short description|Medical condition involving the eye}}
{{distinguish|Ketyconus}}
{{cs1 config|name-list-style=vanc}}
{{Use dmy dates|date=December 2019}}
{{Infobox medical condition (new)
| name            = Keratoconus
| image           = Keratoconus-with-Munsons-sign-USA-1965.jpg
| caption         = The "cone shaped cornea" that is characteristic of Keratoconus
| field           = [[Ophthalmology]], [[optometry]]
| synonyms        = KC, KCN, conical cornea<ref name="rarediseasesorg">{{cite web|title=Keratoconus|url=https://rarediseases.org/rare-diseases/keratoconus/|website=NORD (National Organization for Rare Disorders)|url-status=live|archive-url=https://web.archive.org/web/20170219084455/https://rarediseases.org/rare-diseases/keratoconus/|archive-date=19 February 2017}}</ref>
| pronounce       = KEHR-uh- toh-KOH-nus<ref>{{cite web|title=Keratoconus|url=http://uthscsa.edu/eye/PDFs/Keratoconus.pdf|website=The University of Texas Health Science Center at San Antonio|url-status=live|archive-url=https://web.archive.org/web/20170908185619/http://uthscsa.edu/eye/PDFs/Keratoconus.pdf|archive-date=8 September 2017}}</ref>
| symptoms        = [[Blurry vision]], [[nearsightedness]], [[light sensitivity]]<ref name=NIH2016/>
| onset           = Early adulthood<ref name=NIH2016/>
| duration        =
| causes          = Unknown<ref name=NIH2016/>
| risks           =
| diagnosis       = [[Slit lamp]] exam<ref name=NIH2016/>
| differential    =
| prevention      =
| treatment       = [[Glasses]], [[contacts]], [[surgery]]<ref name=NIH2016/>
| medication      =
| frequency       = ~1 in 2,000 people<ref name=NIH2016/>
| deaths          =
}}
<!-- Definition and symptoms -->
'''Keratoconus''' ('''KC''') is a disorder of the [[Human eye|eye]] that results in progressive thinning and protrusion of the [[cornea]].<ref name=NIH2016/> The protrusion of the cornea may result in [[blurry vision]], [[double vision]], [[nearsightedness]], [[astigmatism|irregular astigmatism]],<ref name="CRFA">{{cite web |title=Cornea Research Foundation of America - Keratoconus |url=http://www.cornea.org/Learning-Center/Conditions-Research-Areas/Keratoconus.aspx#:~:text=Keratoconus%20(KCN)%20is%20a%20disease,impossible%20to%20correct%20with%20spectacles. |website=www.cornea.org}}</ref> and [[light sensitivity]] leading to poor [[Quality of life (healthcare)|quality-of-life]].<ref name=NIH2016/><ref>{{Cite journal|last1=Kandel|first1=Himal|last2=Pesudovs|first2=Konrad|last3=Watson|first3=Stephanie L.|date=March 2020|title=Measurement of Quality of Life in Keratoconus|journal=Cornea|language=en|volume=39|issue=3|pages=386–393|doi=10.1097/ICO.0000000000002170|pmid=31599780|s2cid=204029105|issn=0277-3740}}</ref><ref>{{Cite journal |last=Singh |first=Rohan Bir |last2=Koh |first2=Shizuka |last3=Sharma |first3=Namrata |last4=Woreta |first4=Fasika A. |last5=Hafezi |first5=Farhad |last6=Dua |first6=Harminder S. |last7=Jhanji |first7=Vishal |date=2024-10-24 |title=Keratoconus |url=https://www.nature.com/articles/s41572-024-00565-3 |journal=Nature Reviews Disease Primers |language=en |volume=10 |issue=1 |doi=10.1038/s41572-024-00565-3 |issn=2056-676X|url-access=subscription }}</ref> Usually both eyes are affected.<ref name=NIH2016>{{cite web|title=Facts About the Cornea and Corneal Disease|url=https://nei.nih.gov/health/cornealdisease|website=NEI|access-date=5 November 2016|date=May 2016|url-status=live|archive-url=https://web.archive.org/web/20161122040846/https://www.nei.nih.gov/health/cornealdisease/|archive-date=22 November 2016}}</ref> In more severe cases, a scarring or a [[Fleischer ring|circle]] may be seen within the cornea.<ref name=Mig2010/>

<!-- Cause and diagnosis -->
While the cause is unknown, it is believed to occur due to a combination of [[heredity|genetic]], environmental, and [[hormonal]] factors.<ref name=NIH2016/> Patients with a parent, sibling, or child who has keratoconus have 15 to 67 times higher risk in developing corneal ectasia compared to patients with no affected relatives.<ref name=":1">{{Cite journal|last1=Fecarotta|first1=Christopher|last2=Huang|first2=Wendy|date=2015-07-27|title=Pediatric genetic disease of the cornea|journal=Journal of Pediatric Genetics|language=en|volume=03|issue=4|pages=195–207|doi=10.3233/PGE-14102|issn=2146-4596|pmc=5021007|pmid=27625877}}</ref><ref name=":2">{{Cite journal|last1=Wang|first1=Y.|last2=Rabinowitz|first2=Y.S.|last3=Rotter|first3=J.I.|last4=Yang|first4=H.|date=2000|title=Genetic epidemiological study of keratoconus: Evidence for major gene determination|url=http://dx.doi.org/10.1002/1096-8628(20000828)93:5<403::aid-ajmg11>3.0.co;2-a|journal=[[American Journal of Medical Genetics]]|volume=93|issue=5|pages=403–409|doi=10.1002/1096-8628(20000828)93:5<403::aid-ajmg11>3.0.co;2-a|pmid=10951465|issn=0148-7299|url-access=subscription}}</ref> Proposed environmental factors include rubbing the eyes and [[atopy|allergies]].<ref name=Mig2010/> The underlying mechanism involves changes of the cornea to a [[Cone (geometry)|cone shape]].<ref name=NIH2016/> Diagnosis is most often by topography. Topography measures the curvature of the cornea and creates a colored "map" of the cornea. Keratoconus causes very distinctive changes in the appearance of these maps that allow doctors to make the diagnosis.

<!-- Treatment -->
Initially, the condition can typically be corrected with [[glasses]] or [[soft contact lenses]].<ref name=NIH2016/> As the disease progresses, special contact lenses (such as scleral contact lenses) may be required.<ref name=NIH2016/> In most people, the disease stabilizes after a few years without severe vision problems.<ref name=NIH2016/> In 2016, the FDA approved corneal collagen cross-linking to halt the progression of keratoconus.<ref name=":0" /> In some cases when the cornea becomes dangerously thin or when sufficient vision can no longer be achieved by contact lenses due to steepening of the cornea, scarring, or lens intolerance, corneal cross-linking is not an option, and a corneal transplant may be required.

<!-- Epidemiology and culture -->
Keratoconus affects about 1 in 2,000 people.<ref name=NIH2016/><ref name=Mig2010>{{cite journal|first1=Miguel|last1=Romero-Jiménez|first2=Jacinto|last2=Santodomingo-Rubido|first3=James S.|last3=Wolffsohn|title=Keratoconus: a review|journal=Contact Lens & Anterior Eye: The Journal of the British Contact Lens Association|date=1 August 2010|issn=1476-5411|pages=157–166; quiz 205|volume=33|issue=4|pmid=20537579|doi=10.1016/j.clae.2010.04.006}}</ref> However, some estimates suggest that the incidence may be as high as 1 in 400 individuals.<ref>{{Cite web|title=Keratoconus - NORD|url=https://rarediseases.org/rare-diseases/keratoconus/}}</ref> It occurs most commonly in late childhood to early adulthood.<ref name=NIH2016/> While it occurs in all populations, it may be more frequent in certain [[ethnic group]]s such as those of Asian descent.<ref name=Mig2010/> The word is from the [[Greek language|Greek]] ''kéras'' meaning cornea and the [[Latin language|Latin]] ''cōnus'' meaning cone.<ref>{{cite encyclopedia|url=http://dictionary.reference.com/browse/keratoconus|title=''Keratoconus'' Origin|dictionary=[[dictionary.com]]|access-date=2 November 2015|url-status=live|archive-url=https://web.archive.org/web/20160108112924/http://dictionary.reference.com/browse/keratoconus|archive-date=8 January 2016}}</ref>
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