{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T23:49:01Z","timestamp":1787788141862,"version":"build-2784847793"},"reference-count":36,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T00:00:00Z","timestamp":1747872000000},"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>Keratoconus is a progressive eye disease characterised by thinning and bulging of the cornea, leading to distorted vision. Acute corneal hydrops, a rare and severe complication of keratoconus, occurs when fluid accumulates in the cornea due to a sudden break in its innermost layer, often causing pain, significant visual impairment, and sometimes requiring corneal transplantation. To better understand the risk of disease progression in the contralateral (unaffected) eye, we conducted a retrospective study at two major tertiary hospitals in Auckland, New Zealand. The study included 45 eyes from 45 patients presenting with acute corneal hydrops. Inclusion and exclusion criteria were rigorously applied to ensure that only patients eligible for corneal collagen crosslinking (CXL) at baseline were included, enhancing the clinical relevance of the findings. Patients were followed for a mean duration of 4.73 years. The results showed that 67% of contralateral eyes exhibited progression in at least one tomographic parameter, with 53.3% demonstrating progression in both anterior curvature and corneal thickness parameters. Higher baseline anterior curvature values and male sex were significantly associated with an increased risk of progression (p\u2009=\u20090.022 and p\u2009=\u20090.046, respectively). Nearly half of the eyes with progression had a thinnest corneal thickness of \u2265400\u03bcm, making them eligible for CXL at initial presentation. However, 36% of these eligible eyes dropped below this threshold over the follow-up period, underscoring the importance of timely intervention to preserve treatment options. These findings highlight the importance of regular monitoring of the contralateral eye following acute corneal hydrops, particularly in male patients or those with advanced baseline disease. Immediate CXL may be considered in select cases to prevent disease progression. This study also emphasises the need for early intervention strategies and targeted healthcare services for populations at higher risk, including M\u0101ori and Pacific Peoples in Aotearoa-New Zealand, who experience disproportionately high burdens of keratoconus and health inequities.<\/jats:p>","DOI":"10.1371\/journal.pone.0324750","type":"journal-article","created":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T17:38:39Z","timestamp":1747935519000},"page":"e0324750","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Progression of keratoconus in the contralateral eye following acute corneal hydrops: A retrospective study"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4469-8677","authenticated-orcid":true,"given":"James Steven","family":"Lewis","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charles N.J.","family":"McGhee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jay","family":"Meyer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,5,22]]},"reference":[{"issue":"4","key":"pone.0324750.ref001","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/S0039-6257(97)00119-7","article-title":"Keratoconus","volume":"42","author":"YS Rabinowitz","year":"1998","journal-title":"Surv Ophthalmol"},{"issue":"6","key":"pone.0324750.ref002","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1136\/bjophthalmol-2016-308682","article-title":"The natural history of corneal topographic progression of keratoconus after age 30\u2005years in non-contact lens wearers","volume":"101","author":"A Gokul","year":"2017","journal-title":"Br J Ophthalmol"},{"issue":"4","key":"pone.0324750.ref003","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1016\/S0161-6420(90)32569-1","article-title":"Clinical management of keratoconus. A multicenter analysis","volume":"97","author":"JH Lass","year":"1990","journal-title":"Ophthalmology"},{"issue":"2","key":"pone.0324750.ref004","doi-asserted-by":"crossref","first-page":"927","DOI":"10.1167\/iovs.11-8118","article-title":"Progression of keratoconus by longitudinal assessment with corneal topography","volume":"53","author":"JA Choi","year":"2012","journal-title":"Invest Ophthalmol Vis Sci"},{"issue":"3","key":"pone.0324750.ref005","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1097\/01.ico.0000178728.57435.df","article-title":"Longitudinal changes in corneal curvature in keratoconus","volume":"25","author":"TT McMahon","year":"2006","journal-title":"Cornea"},{"issue":"3","key":"pone.0324750.ref006","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2021.0814","article-title":"Prevalence of keratoconus in persons with down syndrome in a national registry in Norway","volume":"4","author":"O Kristianslund","year":"2021","journal-title":"JAMA Netw Open"},{"issue":"18","key":"pone.0324750.ref007","doi-asserted-by":"crossref","first-page":"10796","DOI":"10.3390\/ijms231810796","article-title":"The underlying relationship between keratoconus and down syndrome","volume":"23","author":"T Akoto","year":"2022","journal-title":"Int J Mol Sci"},{"issue":"3","key":"pone.0324750.ref008","doi-asserted-by":"crossref","DOI":"10.1016\/j.jaapos.2020.02.004","article-title":"Keratoconus and corneal morphology in patients with down syndrome at a pediatric hospital","volume":"24","author":"LM Imbornoni","year":"2020","journal-title":"J AAPOS"},{"key":"pone.0324750.ref009","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.ajo.2016.12.003","article-title":"Repeatability and agreement of Orbscan II, pentacam HR, and Galilei Tomography Systems in corneas with keratoconus","volume":"175","author":"JJ Meyer","year":"2017","journal-title":"Am J Ophthalmol"},{"issue":"5","key":"pone.0324750.ref010","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1111\/opo.12131","article-title":"When to use the Bonferroni correction","volume":"34","author":"RA Armstrong","year":"2014","journal-title":"Ophthalmic Physiol Opt"},{"key":"pone.0324750.ref011","first-page":"96","article-title":"Classic keratocene and crude keratocene; Unitary arguments","volume":"111","author":"M Amsler","year":"1946","journal-title":"Ophthalmologica"},{"issue":"5","key":"pone.0324750.ref012","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1097\/APO.0000000000000557","article-title":"Corneal crosslinking: present and future","volume":"11","author":"L Angelo","year":"2022","journal-title":"Asia Pac J Ophthalmol (Phila)"},{"issue":"11","key":"pone.0324750.ref013","doi-asserted-by":"crossref","first-page":"1416","DOI":"10.1097\/ICO.0000000000000935","article-title":"Effects of atopic syndrome on keratoconus","volume":"35","author":"M Shajari","year":"2016","journal-title":"Cornea"},{"issue":"8","key":"pone.0324750.ref014","doi-asserted-by":"crossref","first-page":"2057","DOI":"10.1007\/s00417-021-05081-8","article-title":"Eye rubbing in the aetiology of keratoconus: a systematic review and meta-analysis","volume":"259","author":"S Sahebjada","year":"2021","journal-title":"Graefes Arch Clin Exp Ophthalmol"},{"issue":"6","key":"pone.0324750.ref015","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1097\/APO.0000000000000334","article-title":"The enigma of environmental factors in keratoconus","volume":"9","author":"AZ Crawford","year":"2020","journal-title":"Asia Pac J Ophthalmol (Phila)"},{"issue":"2","key":"pone.0324750.ref016","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1136\/bjophthalmol-2020-316481","article-title":"Progression of keratoconus in children and adolescents","volume":"107","author":"JJ Meyer","year":"2023","journal-title":"Br J Ophthalmol"},{"issue":"6","key":"pone.0324750.ref017","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1016\/j.jaapos.2016.08.006","article-title":"Tomographic indices as possible risk factors for progression in pediatric keratoconus","volume":"20","author":"A Hamilton","year":"2016","journal-title":"J AAPOS"},{"issue":"4","key":"pone.0324750.ref018","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1016\/j.ajo.2005.05.029","article-title":"Risk factors for progression to penetrating keratoplasty in patients with keratoconus","volume":"140","author":"SW Reeves","year":"2005","journal-title":"Am J Ophthalmol"},{"issue":"5","key":"pone.0324750.ref019","doi-asserted-by":"crossref","first-page":"921","DOI":"10.1016\/j.ajo.2014.01.017","article-title":"Acute corneal hydrops in keratoconus - new perspectives","volume":"157","author":"JC Fan Gaskin","year":"2014","journal-title":"Am J Ophthalmol"},{"issue":"2","key":"pone.0324750.ref020","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1111\/cxo.12048","article-title":"The Auckland keratoconus study: identifying predictors of acute corneal hydrops in keratoconus","volume":"96","author":"JC Fan Gaskin","year":"2013","journal-title":"Clin Exp Optom"},{"issue":"1","key":"pone.0324750.ref021","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1097\/ICO.0000000000002672","article-title":"The aotearoa research into keratoconus study: geographic distribution, demographics, and clinical characteristics of keratoconus in New Zealand","volume":"41","author":"A Gokul","year":"2022","journal-title":"Cornea"},{"issue":"11","key":"pone.0324750.ref022","doi-asserted-by":"crossref","first-page":"753","DOI":"10.3928\/1081597X-20121011-01","article-title":"Progression of keratoconus and efficacy of pediatric [corrected] corneal collagen cross-linking in children and adolescents","volume":"28","author":"N Chatzis","year":"2012","journal-title":"J Refract Surg"},{"issue":"9","key":"pone.0324750.ref023","first-page":"1409","article-title":"Unilateral keratoconus. Incidence and quantitative topographic analysis","volume":"104","author":"DR Holland","year":"1997","journal-title":"Ophthalmology"},{"issue":"5","key":"pone.0324750.ref024","doi-asserted-by":"crossref","first-page":"620","DOI":"10.1016\/S0002-9394(02)02220-1","article-title":"Riboflavin\/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus","volume":"135","author":"G Wollensak","year":"2003","journal-title":"Am J Ophthalmol"},{"issue":"5","key":"pone.0324750.ref025","article-title":"Efficacy of corneal collagen cross-linking for treatment of keratoconus: a meta-analysis of randomized controlled trials","volume":"10","author":"J Li","year":"2015","journal-title":"PLoS One"},{"key":"pone.0324750.ref026","doi-asserted-by":"crossref","first-page":"8145651","DOI":"10.1155\/2017\/8145651","article-title":"Corneal collagen cross-linking for keratoconus: systematic review","volume":"2017","author":"H Kobashi","year":"2017","journal-title":"Biomed Res Int"},{"issue":"1","key":"pone.0324750.ref027","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.jcrs.2014.09.033","article-title":"Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results","volume":"41","author":"F Raiskup","year":"2015","journal-title":"J Cataract Refract Surg"},{"issue":"10","key":"pone.0324750.ref028","doi-asserted-by":"crossref","first-page":"1256","DOI":"10.1097\/ICO.0000000000002376","article-title":"Prospective clinical study of keratoconus progression in patients awaiting corneal cross-linking","volume":"39","author":"YW Goh","year":"2020","journal-title":"Cornea"},{"key":"pone.0324750.ref029","article-title":"Contemporary treatment paradigms in keratoconus","volume":"34","author":"CNJ McGhee","year":"2015","journal-title":"Cornea"},{"issue":"11","key":"pone.0324750.ref030","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1038\/eye.2015.151","article-title":"Cost effectiveness of collagen crosslinking for progressive keratoconus in the UK NHS","volume":"29","author":"HA Salmon","year":"2015","journal-title":"Eye (Lond)"},{"issue":"10","key":"pone.0324750.ref031","doi-asserted-by":"crossref","first-page":"1485","DOI":"10.1016\/j.ophtha.2017.04.011","article-title":"Cost-effectiveness analysis of corneal collagen crosslinking for progressive keratoconus","volume":"124","author":"DA Godefrooij","year":"2017","journal-title":"Ophthalmology"},{"issue":"8","key":"pone.0324750.ref032","doi-asserted-by":"crossref","first-page":"1108","DOI":"10.1016\/j.ophtha.2017.03.019","article-title":"Corneal collagen cross-linking in the management of keratoconus in Canada: a cost-effectiveness analysis","volume":"124","author":"VC Leung","year":"2017","journal-title":"Ophthalmology"},{"issue":"1","key":"pone.0324750.ref033","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1080\/13696998.2020.1851556","article-title":"Corneal cross-linking versus conventional management for keratoconus: a lifetime economic model","volume":"24","author":"RL Lindstrom","year":"2021","journal-title":"J Med Econ"},{"issue":"7","key":"pone.0324750.ref034","doi-asserted-by":"crossref","first-page":"1808","DOI":"10.1038\/s41433-021-01444-x","article-title":"What are the costs, capacity, and clinical implications of \u201cwaiting for documented progression\u201d in young West of Scotland patients prior to collagen cross linking?","volume":"35","author":"A Simpson","year":"2021","journal-title":"Eye (Lond)"},{"key":"pone.0324750.ref035","doi-asserted-by":"crossref","first-page":"115315","DOI":"10.1016\/j.socscimed.2022.115315","article-title":"Universal healthcare for all? M\u0101ori health inequalities in Aotearoa New Zealand, 1975-2000","volume":"319","author":"H Brown","year":"2023","journal-title":"Soc Sci Med"},{"issue":"32","key":"pone.0324750.ref036","first-page":"2","article-title":"Closing the gaps: An update on indicators of inequality for Maori and pacific people.","author":"L Marriott","year":"2021","journal-title":"Journal of New Zealand Studies"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0324750","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T17:38:48Z","timestamp":1747935528000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0324750"}},"subtitle":[],"editor":[{"given":"Andrzej","family":"Grzybowski","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,5,22]]},"references-count":36,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2025,5,22]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0324750","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,22]]}}}