{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T17:53:03Z","timestamp":1789235583855,"version":"build-2803163510"},"reference-count":30,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2020,11,16]],"date-time":"2020-11-16T00:00:00Z","timestamp":1605484800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Acta Ophthalmologica"],"published-print":{"date-parts":[[2021,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To estimate the national prevalence and incidence of keratoconus in Norway.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In this epidemiologic study, data were obtained from the Norwegian Patient Registry, which provides information from all publicly funded specialist care in Norway. Prevalence of keratoconus was estimated from the total number of patients registered with this diagnosis and incidence from the annual frequency of first\u2010time registrations of patients up to 40\u00a0years of age in the period 2010\u20132018. Data on age and gender of the keratoconus patients were also gathered.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 9832 keratoconus patients were registered. The estimated prevalence in the general population was 192.1 per 100\u00a0000 (95% confidence interval (CI): 188.3\u2013195.9), and the estimated annual incidence was 19.8 per 100\u00a0000 (95% CI: 18.1\u201321.5). There was a predominance of males (73%), and mean age for all patients was 37.5\u00a0years at first registration in this period.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study reports the frequency of keratoconus from a national patient register during a time period with available modern diagnostic tools. The estimated prevalence and incidence were higher than most previous estimates and show that keratoconus is not a rare condition. As screening was not part of the study, the true prevalence in the general population may be even higher.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/aos.14668","type":"journal-article","created":{"date-parts":[[2020,11,16]],"date-time":"2020-11-16T05:56:18Z","timestamp":1605506178000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["Prevalence and incidence of keratoconus in Norway: a nationwide register study"],"prefix":"10.1111","volume":"99","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3390-9811","authenticated-orcid":false,"given":"Olav","family":"Kristianslund","sequence":"first","affiliation":[{"name":"Department of Ophthalmology Oslo University Hospital Nydalen Norway"},{"name":"Institute of Clinical Medicine University of Oslo Oslo Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne Marie","family":"Hagem","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology Oslo University Hospital Nydalen Norway"},{"name":"Institute of Clinical Medicine University of Oslo Oslo Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andreas","family":"Thorsrud","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology Oslo University Hospital Nydalen Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liv","family":"Drolsum","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology Oslo University Hospital Nydalen Norway"},{"name":"Institute of Clinical Medicine University of Oslo Oslo Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2020,11,16]]},"reference":[{"key":"e_1_2_5_2_1","doi-asserted-by":"publisher","DOI":"10.1155\/2018\/5983530"},{"key":"e_1_2_5_3_1","doi-asserted-by":"publisher","DOI":"10.1136\/bjo.2005.074955"},{"key":"e_1_2_5_4_1","doi-asserted-by":"publisher","DOI":"10.1111\/aos.14082"},{"key":"e_1_2_5_5_1","doi-asserted-by":"publisher","DOI":"10.1097\/ICO.0b013e3182068adc"},{"key":"e_1_2_5_6_1","doi-asserted-by":"publisher","DOI":"10.1038\/sj.eye.6701677"},{"key":"e_1_2_5_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10792-018-0965-4"},{"key":"e_1_2_5_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajo.2005.03.078"},{"key":"e_1_2_5_9_1","doi-asserted-by":"publisher","DOI":"10.1038\/sj.eye.6700652"},{"key":"e_1_2_5_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/aos.13095"},{"key":"e_1_2_5_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ophtha.2017.04.011"},{"key":"e_1_2_5_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajo.2016.12.015"},{"key":"e_1_2_5_13_1","doi-asserted-by":"publisher","DOI":"10.1155\/2015\/795738"},{"key":"e_1_2_5_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcrs.2010.07.030"},{"key":"e_1_2_5_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ophtha.2017.03.052"},{"key":"e_1_2_5_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajo.2018.04.027"},{"key":"e_1_2_5_17_1","first-page":"1","article-title":"Clinical and epidemiological features of keratoconus genetic and external factors in the pathogenesis of the disease","volume":"178","author":"Ihalainen A","year":"1986","journal-title":"Acta Ophthalmol Suppl"},{"key":"e_1_2_5_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajo.2009.06.024"},{"key":"e_1_2_5_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9394(86)90817-2"},{"key":"e_1_2_5_20_1","doi-asserted-by":"publisher","DOI":"10.1016\/0039-6257(84)90094-8"},{"key":"e_1_2_5_21_1","doi-asserted-by":"publisher","DOI":"10.1097\/ICO.0000000000002206"},{"key":"e_1_2_5_22_1","doi-asserted-by":"publisher","DOI":"10.3109\/09286586.2011.560747"},{"key":"e_1_2_5_23_1","doi-asserted-by":"publisher","DOI":"10.1111\/aos.13296"},{"key":"e_1_2_5_24_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0420.2007.00981.x"},{"key":"e_1_2_5_25_1","doi-asserted-by":"publisher","DOI":"10.1097\/ICO.0000000000002054"},{"key":"e_1_2_5_26_1","doi-asserted-by":"publisher","DOI":"10.1038\/eye.2000.154"},{"key":"e_1_2_5_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0161-6420(02)01121-1"},{"key":"e_1_2_5_28_1","doi-asserted-by":"publisher","DOI":"10.1097\/ICO.0000000000000460"},{"key":"e_1_2_5_29_1","unstructured":"Statistics Norway(2019). 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