{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T02:42:02Z","timestamp":1777603322802,"version":"3.51.4"},"reference-count":27,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T00:00:00Z","timestamp":1644278400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Aspherical- and multi-curve rigid gas-permeable hard contact lenses (HCLs) have a flattened curve in the peripheral zone and are mostly used for patients with keratoconus who cannot wear glasses, soft contact lenses, or spherical HCLs. In this retrospective study, a total of 95 eyes of 77 patients who used aspherical- or multi-curve HCLs (mean age: 40.0 \u00b1 11.0 years) were evaluated. This study examined the types of aspherical- and multi-curve HCLs, best-corrected visual acuity (BCVA) values before and after wearing HCLs, the association with the Amsler-Krumeich classification, duration of wear, corneal\/conjunctival disorder, and the frequency of changing HCLs. There were 78 eyes that used aspherical-curve HCLs and 17 that used multi-curve HCLs. BCVA significantly improved from 0.42 logMAR to 0.06 logMAR after wearing either form of HCL. The Amsler-Krumeich classification showed that aspherical-curve HCLs were commonly used for patients with stage 2 keratoconus, and multi-curve HCLs were commonly used for stage 4 patients. The BCVA values were worse when the disease stage was more severe (stages 3 and 4) regardless of HCL type. The mean base curve of the lenses was steeper in multi-curve HCLs than in aspherical-curve HCLs. The more severe the disease stage, the steeper the base curve in both aspherical- and multi-curve HCLs. The duration of wear significantly improved from 2.1 h to 10.2 h, and corneal\/conjunctival disorder similarly improved. The mean frequency of changing HCL types was 1.1 times. This study suggests that a flat peripheral curve design with aspherical- and multi-curve HCLs is useful for patients with keratoconus.<\/jats:p>","DOI":"10.1371\/journal.pone.0263506","type":"journal-article","created":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T18:29:27Z","timestamp":1644344967000},"page":"e0263506","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":4,"title":["Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus"],"prefix":"10.1371","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3561-4462","authenticated-orcid":true,"given":"Takashi","family":"Kumanomido","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazutaka","family":"Kamiya","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masahide","family":"Takahashi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tatsuhiko","family":"Tsujisawa","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hideki","family":"Hayakawa","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wakako","family":"Ando","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoshikazu","family":"Utsumi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nobuyuki","family":"Shoji","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2022,2,8]]},"reference":[{"key":"pone.0263506.ref001","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s10792-014-9971-3","article-title":"Tear film inflammatory mediators in patients with keratoconus","volume":"35","author":"R Sorkhabi","year":"2015","journal-title":"Int Ophthalmol"},{"key":"pone.0263506.ref002","doi-asserted-by":"crossref","first-page":"843","DOI":"10.1038\/eye.2015.63","article-title":"Keratoconus: an inflammatory disorder?","volume":"29","author":"V Galvis","year":"2015","journal-title":"Eye (Lond)."},{"key":"pone.0263506.ref003","doi-asserted-by":"crossref","first-page":"7803029","DOI":"10.1155\/2017\/7803029","article-title":"Molecular and Histopathological Changes Associated with Keratoconus","volume":"2017","author":"ML Khaled","year":"2017","journal-title":"BioMed Res Int"},{"key":"pone.0263506.ref004","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/S0039-6257(97)00119-7","volume":"42","author":"YS Rabinowitz","year":"1998","journal-title":"Keratoconus. 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