{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T18:09:21Z","timestamp":1789063761728,"version":"build-2803163510"},"reference-count":43,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","license":[{"start":{"date-parts":[[2024,10,1]],"date-time":"2024-10-01T00:00:00Z","timestamp":1727740800000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2024,10]]},"abstract":"<jats:sec>\n                    <jats:title>Purpose:<\/jats:title>\n                    <jats:p>To investigate the outcomes of asymmetric (AS) Keraring intracorneal ring segments (ICRS) implantation in patients with all types, types 2 (Duck) and 3 (Snowman) of keratoconus.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>The protocol for this systematic review was registered in the International Prospective Register of Systematic Reviews (CRD42023482841). From inception to December 2023, we systematically searched PubMed, Embase, Cochrane Library, and Web of Science. Due to heterogeneity, a random-effects model was used for all analyses. Publication bias was evaluated using the risk of bias in nonrandomized studies of interventions tool, and sensitivity analyses included leave-one-out and Baujat methods. Meta-regression explored the effects of age, sex, and follow-up time on heterogeneous outcomes. Software R version 4.3.2 was used for statistical analysis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>From 318 initial articles, 7 studies (3 prospective and 4 retrospective cohorts) met inclusion criteria, pooling 435 eyes from 365 patients across seven countries. Significant improvements were observed postoperatively for uncorrected distance visual acuity (mean differences [MD]: 0.49, confidence interval [CI]: 0.42\u20130.57), corrected distance visual acuity (CDVA) (MD: 0.18, CI: 0.07\u20130.29), topographic astigmatism (MD: 2.04 diopter [D], CI: 1.51\u20132.58 D), maximum keratometric (MD: 4.42 D, CI: 3.24\u20135.60 D), comatic aberration (MD: 0.56 \u00b5m, CI: 0.29\u20130.82 \u00b5m), refractive astigmatism (MD: \u22122.52 D, CI: \u22123.08 to \u22121.95 D), spherical equivalent (SE) (MD: \u22122.86 D, CI: \u22124.02 to \u22121.70 D), and mean keratometry (MD: 2.92 D, CI: 1.94\u20133.91 D). Subgroup analyses for keratoconus types 2 and 3 revealed consistent improvements across most parameters. Sensitivity analysis identified specific studies influencing heterogeneity without altering statistical significance. Meta-regression revealed associations for follow-up and male gender in SE, CDVA, and topographic astigmatism, while age showed no consistent effect.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>The implantation of AS Keraring ICRS was safe and effective, improving visual, topographic, and refractive parameters in patients with keratoconus of phenotype types 2, 3, and all types.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.4103\/joco.joco_151_24","type":"journal-article","created":{"date-parts":[[2025,9,18]],"date-time":"2025-09-18T22:02:39Z","timestamp":1758232959000},"page":"325-341","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":1,"title":["Asymmetric Intracorneal Ring Segments for the Management of Keratoconus: A Systematic Review and Meta-Analysis"],"prefix":"10.4103","volume":"36","author":[{"given":"Dillan Cunha","family":"Amaral","sequence":"first","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Facuty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Milton Ruiz","family":"Alves","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Faculty of Medicine, University of S\u00e3o Paulo, S\u00e3o Paulo, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jaime","family":"Guedes","sequence":"additional","affiliation":[{"name":"Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helv\u00e9cio Neves Feitosa","family":"Filho","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, University of Fortaleza, Fortaleza, CE, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eduardo Henrique Cassins","family":"Aguiar","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Facuty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dhiogo Cezar","family":"Correa","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Faculty of Medicine, University of S\u00e3o Paulo, S\u00e3o Paulo, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evandro Ribeiro","family":"Diniz","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Faculty of Medicine, University of S\u00e3o Paulo, S\u00e3o Paulo, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raiza","family":"Jacometti","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Faculty of Medicine, University of S\u00e3o Paulo, S\u00e3o Paulo, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ricardo Noguera","family":"Louzada","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology and Otorhinolaryngology, Facuty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil"},{"name":"Department of Ophthalmology and Otorhinolaryngology, Faculty of Medicine, University of S\u00e3o Paulo, S\u00e3o Paulo, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2025,9,18]]},"reference":[{"key":"R1-20250918","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1016\/j.ophtha.2003.06.020","article-title":"Longitudinal study of the normal eyes in unilateral keratoconus patients","volume":"111","author":"Li","year":"2004","journal-title":"Ophthalmology"},{"key":"R2-20250918","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/0002-9394(86)90817-2","article-title":"A 48-year clinical and epidemiologic study of keratoconus","volume":"101","author":"Kennedy","year":"1986","journal-title":"Am J Ophthalmol"},{"key":"R3-20250918","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.clae.2010.04.006","article-title":"Keratoconus: A review","volume":"33","author":"Romero-Jim\u00e9nez","year":"2010","journal-title":"Cont Lens Anterior Eye"},{"key":"R4-20250918","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1002\/1096-8628(20000828)93:5<403::AID-AJMG11>3.0.CO;2-A","article-title":"Genetic epidemiological study of keratoconus: Evidence for major gene determination","volume":"93","author":"Wang","year":"2000","journal-title":"Am J Med Genet"},{"key":"R5-20250918","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1097\/ICO.0000000000002206","article-title":"Epidemiological association between systemic diseases and keratoconus in a Korean population: A 10-year nationwide cohort study","volume":"39","author":"Lee","year":"2020","journal-title":"Cornea"},{"key":"R6-20250918","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.ajo.2018.04.027","article-title":"Prevalence and incidence of keratoconus in South Korea: A nationwide population-based study","volume":"192","author":"Hwang","year":"2018","journal-title":"Am J Ophthalmol"},{"key":"R7-20250918","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.clae.2016.10.001","article-title":"Systematic review comparing penetrating keratoplasty and deep anterior lamellar keratoplasty for management of keratoconus","volume":"40","author":"Henein","year":"2017","journal-title":"Cont Lens Anterior Eye"},{"key":"R8-20250918","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1016\/S0886-3350(00)00430-2","article-title":"Penetrating keratoplasty for keratoconus: A long-term review of results and complications","volume":"26","author":"Olson","year":"2000","journal-title":"J Cataract Refract Surg"},{"key":"R9-20250918","doi-asserted-by":"crossref","first-page":"556","DOI":"10.3928\/1081-597X-19970901-12","article-title":"Corneal asphericity in eye bank eyes implanted with the intrastromal corneal ring","volume":"13","author":"Burris","year":"1997","journal-title":"J Refract Surg"},{"key":"R10-20250918","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1186\/s40662-016-0040-z","article-title":"The use of intracorneal ring segments in keratoconus","volume":"3","author":"Vega-Estrada","year":"2016","journal-title":"Eye Vis (Lond)"},{"key":"R11-20250918","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1167\/8.2.13","article-title":"How keratoconus influences optical performance of the eye","volume":"8","author":"Tan","year":"2008","journal-title":"J Vis"},{"key":"R12-20250918","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.jcrs.2016.11.044","article-title":"Sequential intrastromal corneal ring segment and monofocal intraocular lens implantation for keratoconus and cataract: Long-term follow-up","volume":"43","author":"Alfonso","year":"2017","journal-title":"J Cataract Refract Surg"},{"key":"R13-20250918","doi-asserted-by":"crossref","first-page":"4415","DOI":"10.2147\/OPTH.S283387","article-title":"Asymmetric thickness intracorneal ring segments for keratoconus","volume":"14","author":"Baptista","year":"2020","journal-title":"Clin Ophthalmol"},{"key":"R15-20250918","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1016\/j.jfo.2022.11.012","article-title":"Asymmetric intracorneal ring segments in the treatment of snowman phenotype keratoconus","volume":"46","author":"Coskunseven","year":"2023","journal-title":"J Fr Ophtalmol"},{"key":"R16-20250918","doi-asserted-by":"crossref","first-page":"552","DOI":"10.3928\/1081597X-20210526-01","article-title":"Comparative study of asymmetric versus non-asymmetric intrastromal corneal ring segments for the management of keratoconus","volume":"37","author":"Barugel","year":"2021","journal-title":"J Refract Surg"},{"key":"R17-20250918","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1167\/tvst.11.3.19","article-title":"Optical evaluation of intracorneal ring segment surgery in keratoconus","volume":"11","author":"Alejandre","year":"2022","journal-title":"Transl Vis Sci Technol"},{"key":"R18-20250918","doi-asserted-by":"crossref","first-page":"n71","DOI":"10.1136\/bmj.n71","article-title":"The PRISMA 2020 statement: An updated guideline for reporting systematic reviews","volume":"372","author":"Page","year":"2021","journal-title":"BMJ"},{"key":"R19-20250918","doi-asserted-by":"crossref","first-page":"i4919","DOI":"10.1136\/bmj.i4919","article-title":"ROBINS-I: A tool for assessing risk of bias in non-randomised studies of interventions","volume":"355","author":"Sterne","year":"2016","journal-title":"BMJ"},{"key":"R20-20250918","article-title":"Cochrane Handbook for Systematic Reviews of Interventions version 6.5 (updated August 2024)","author":"Higgins","year":"2024","journal-title":"Cochrane"},{"key":"R21-20250918","doi-asserted-by":"crossref","first-page":"e0051","DOI":"10.37039\/1982.8551.20240051","article-title":"Visual, topographic, and refractive outcomes of the implantation of asymmetric segments of the intrastromal corneal ring in keratoconus","volume":"83","author":"Diniz","year":"2024","journal-title":"Rev Bras Oftalmol"},{"key":"R22-20250918","doi-asserted-by":"crossref","first-page":"2939","DOI":"10.4103\/ijo.IJO_2770_21","article-title":"Clinical, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment implantations in duck-type keratoconus","volume":"70","author":"Coskunseven","year":"2022","journal-title":"Indian J Ophthalmol"},{"key":"R23-20250918","doi-asserted-by":"crossref","first-page":"2835","DOI":"10.1007\/s10792-020-01467-5","article-title":"Visual, refractive and topographic outcomes of progressive thickness intrastromal corneal ring segments for keratoconic eyes","volume":"40","author":"Co\u015fkunseven","year":"2020","journal-title":"Int Ophthalmol"},{"key":"R24-20250918","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1097\/ICO.0000000000001945","article-title":"Long-term follow-up of intrastromal corneal ring segment implantation in pediatric keratoconus","volume":"38","author":"Alfonso","year":"2019","journal-title":"Cornea"},{"key":"R25-20250918","doi-asserted-by":"crossref","first-page":"69","DOI":"10.3928\/1081-597X-20010101-09","article-title":"Surgical treatment of keratoconus at the turn of the 20th century","volume":"17","author":"Sekundo","year":"2001","journal-title":"J Refract Surg"},{"key":"R26-20250918","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1111\/j.1442-9071.2010.02197.x","article-title":"Intracorneal ring segments in ectatic corneal disease \u2013 A review","volume":"38","author":"Pi\u00f1ero","year":"2010","journal-title":"Clin Exp Ophthalmol"},{"key":"R27-20250918","doi-asserted-by":"crossref","first-page":"451","DOI":"10.4103\/0301-4738.116065","article-title":"Intrastromal corneal ring segments for management of keratoconus","volume":"61","author":"Ganesh","year":"2013","journal-title":"Indian J Ophthalmol"},{"key":"R28-20250918","doi-asserted-by":"crossref","first-page":"645","DOI":"10.3928\/1081-597X-20031101-06","article-title":"Ferrara intrastromal corneal ring segments for severe keratoconus","volume":"19","author":"Miranda","year":"2003","journal-title":"J Refract Surg"},{"key":"R29-20250918","doi-asserted-by":"crossref","first-page":"812","DOI":"10.1016\/j.jcrs.2003.12.005","article-title":"Ferrara intracorneal ring segments for keratoconus","volume":"30","author":"Kwitko","year":"2004","journal-title":"J Cataract Refract Surg"},{"key":"R30-20250918","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1097\/IIO.0b013e3182774453","article-title":"INTACS for keratoconus and ectasia after LASIK","volume":"53","author":"Rabinowitz","year":"2013","journal-title":"Int Ophthalmol Clin"},{"key":"R31-20250918","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1007\/s12177-008-9007-1","article-title":"Prediction of cis-regulatory elements controlling genes differentially expressed by retinal and choroidal vascular endothelial cells","volume":"1","author":"Choi","year":"2008","journal-title":"J Ocul Biol Dis Infor"},{"key":"R32-20250918","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1016\/S0886-3350(00)00451-X","article-title":"Correcting keratoconus with intracorneal rings","volume":"26","author":"Colin","year":"2000","journal-title":"J Cataract Refract Surg"},{"key":"R33-20250918","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1097\/00055735-199808000-00003","article-title":"Intrastromal corneal ring technology: Results and indications","volume":"9","author":"Burris","year":"1998","journal-title":"Curr Opin Ophthalmol"},{"key":"R34-20250918","doi-asserted-by":"crossref","first-page":"1421","DOI":"10.1097\/ICO.0000000000000978","article-title":"Intrastromal corneal ring segment implantation in 409 paracentral keratoconic eyes","volume":"35","author":"Fern\u00e1ndez-Vega","year":"2016","journal-title":"Cornea"},{"key":"R35-20250918","first-page":"146","article-title":"The theory of corneal curvature change with the intrastromal corneal ring","volume":"15","author":"Fleming","year":"1989","journal-title":"CLAO J"},{"key":"R36-20250918","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1097\/ICO.0000000000002160","article-title":"Clinical outcomes of an asymmetric model of intrastromal corneal ring segments for the correction of keratoconus","volume":"39","author":"Prisant","year":"2020","journal-title":"Cornea"},{"key":"R37-20250918","doi-asserted-by":"crossref","first-page":"108","DOI":"10.5005\/jp-journals-10025-1062","article-title":"Accuracy of topometric indices for distinguishing between keratoconic and normal corneas","volume":"2","author":"Salom\u00e3o","year":"2013","journal-title":"Int J Keratoconus Ectatic Corneal Dis"},{"key":"R38-20250918","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1097\/01.ico.0000167883.63266.60","article-title":"Modified intracorneal ring segment implantations (INTACS) for the management of moderate to advanced keratoconus: Efficacy and complications","volume":"25","author":"Kanellopoulos","year":"2006","journal-title":"Cornea"},{"key":"R39-20250918","doi-asserted-by":"crossref","first-page":"1886","DOI":"10.1016\/j.jcrs.2007.06.055","article-title":"Intracorneal ring segment implantation for the management of keratoconus: Safety and efficacy","volume":"33","author":"Zare","year":"2007","journal-title":"J Cataract Refract Surg"},{"key":"R40-20250918","doi-asserted-by":"crossref","first-page":"392","DOI":"10.3928\/1081597X-20120509-01","article-title":"Refractive and topographic stability of intacs in eyes with progressive keratoconus: Five-year follow-up","volume":"28","author":"Bedi","year":"2012","journal-title":"J Refract Surg"},{"key":"R41-20250918","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1016\/j.jcrs.2006.01.064","article-title":"European clinical evaluation: Use of intacs for the treatment of keratoconus","volume":"32","author":"Colin","year":"2006","journal-title":"J Cataract Refract Surg"},{"key":"R42-20250918","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1097\/j.jcrs.0000000000000525","article-title":"Clinical evaluation of the effectiveness of asymmetric intracorneal ring with variable thickness and width for the management of keratoconus","volume":"47","author":"Cui\u00f1a","year":"2021","journal-title":"J Cataract Refract Surg"},{"key":"R43-20250918","doi-asserted-by":"crossref","first-page":"693","DOI":"10.3928\/1081597X-20210712-04","article-title":"Clinical outcomes of femtosecond laser-assisted implantation of asymmetric ICRS in keratoconus with no coincidence of topographic and comatic axes","volume":"37","author":"Kammoun","year":"2021","journal-title":"J Refract Surg"},{"key":"R44-20250918","doi-asserted-by":"crossref","first-page":"e0257222","DOI":"10.1371\/journal.pone.0257222","article-title":"Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: A 2D finite-element model","volume":"16","author":"Garc\u00eda","year":"2021","journal-title":"PLoS One"}],"container-title":["Journal of Current Ophthalmology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ovid.com\/10.4103\/joco.joco_151_24","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T13:44:15Z","timestamp":1787838255000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ovid.com\/10.4103\/joco.joco_151_24"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10]]},"references-count":43,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2024]]}},"URL":"https:\/\/doi.org\/10.4103\/joco.joco_151_24","relation":{},"ISSN":["2452-2325"],"issn-type":[{"value":"2452-2325","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10]]},"assertion":[{"value":"2024-07-26","name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-11-26","name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}}]}}