{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,14]],"date-time":"2026-03-14T17:17:45Z","timestamp":1773508665636,"version":"3.50.1"},"reference-count":14,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,10,6]],"date-time":"2025-10-06T00:00:00Z","timestamp":1759708800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,10,6]],"date-time":"2025-10-06T00:00:00Z","timestamp":1759708800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Beijing medical award foundation","award":["YXJL-2021-0815-0547"],"award-info":[{"award-number":["YXJL-2021-0815-0547"]}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Ophthalmol"],"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>There are several clinical signs that may contribute to the diagnosis of keratoconus. Their appearance is associated with the evolution of keratoconus. In this case, the formation of a halo on the iris in a patient with stage IV keratoconus was reported. This halo sigh is a novel one and has not been reported earlier.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Case presentation<\/jats:title>\n            <jats:p>A 30-year-old woman presented to the ophthalmology clinic with one year history of vision deterioration to finger counting in her left eye. A diagnosis of keratoconus was made due to the inferior-central corneal steepening and thinning. When the slit-lamp light projects onto the cone, a halo forms on the iris and shifts its shape and location as the irradiation angle changes.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusion<\/jats:title>\n            <jats:p>A halo sign was observed on the iris of a patient with stage IV keratoconus (Amsler-Krumeich classification) when the slit-lamp beam was projected onto the corneal cone.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/s12886-025-04400-5","type":"journal-article","created":{"date-parts":[[2025,10,6]],"date-time":"2025-10-06T14:01:28Z","timestamp":1759759288000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Halo sign in keratoconus: a case report"],"prefix":"10.1186","volume":"25","author":[{"given":"Hui","family":"He","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lijun","family":"Qu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,10,6]]},"reference":[{"issue":"1","key":"4400_CR1","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1038\/s41421-022-00397-z","volume":"8","author":"S Dou","year":"2022","unstructured":"Dou S, Wang Q, Zhang B, Wei C, Wang H, Liu T, Duan H, Jiang H, Liu M, Qi X, et al. 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Informed written consent had been obtained from the patient. We confirm that this study was conducted in full compliance with the principles of the Declaration of Helsinki.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Informed written consent had been obtained from the patient.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"548"}}