{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T16:13:58Z","timestamp":1790612038438,"version":"4.1.0"},"reference-count":45,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T00:00:00Z","timestamp":1779840000000},"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>Horizontal concomitant strabismus is a common pediatric ocular disorder influenced by underlying refractive error patterns, yet evidence from Iraq remains limited. This study characterized refractive profiles in esotropia and exotropia and identified refractive predictors of each subtype. In this retrospective multicenter clinic-based case-comparison study, medical records of 2,256 children aged 4\u201315 years evaluated at three tertiary pediatric ophthalmology centers in Iraq were reviewed; 1,012 met the criteria for horizontal concomitant strabismus (642 esotropia and 370 exotropia), while 1,244 non-strabismic children served as controls. All participants underwent standardized cycloplegic refraction, visual acuity assessment, and ocular alignment testing. Group differences were examined using Chi-square tests, and logistic regression was used to identify refractive predictors. Children with esotropia were younger (mean age 8.24\u2009\u00b1\u20092.89 years) and exhibited a marked hyperopic profile, with 78% having spherical equivalent hyperopia\u2009\u2265\u2009+2.00 D; clinically significant anisometropia (\u22652.50 D) was present in 33.8% of cases. Exotropia occurred at a slightly older age (8.75\u2009\u00b1\u20092.89 years) and was associated with higher proportions of myopia (53.5%) and astigmatism \u22651.00 D (55.7%). Across the full cohort, myopic refractive error (SE\u2009&lt;\u22120.50 D) was present in 310 children (13.7%), hyperopic refractive error (SE\u2009\u2265\u2009+2.00 D) in 1,002 (44.4%), astigmatism \u22651.00 D in 555 (24.6%), and anisometropia \u22650.50 D in 1,489 (66.0%). In multivariable analysis, moderate-to-high hyperopia strongly predicted esotropia, whereas myopia and clinically significant astigmatism independently predicted exotropia. These findings show contrasting refractive profiles in Iraqi children with esotropia and exotropia and support the clinical value of early cycloplegic refraction in children with suspected ocular misalignment.<\/jats:p>","DOI":"10.1371\/journal.pone.0349697","type":"journal-article","created":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T17:29:09Z","timestamp":1779902949000},"page":"e0349697","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Distribution of refractive errors and horizontal concomitant strabismus in Iraqi children"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4892-1346","authenticated-orcid":true,"given":"Hassan A.","family":"Aljaberi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saeed","family":"Rahmani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Humam H.","family":"Alrikabi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,5,27]]},"reference":[{"issue":"1","key":"pone.0349697.ref001","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1186\/s12886-024-03477-8","article-title":"Prevalence and characteristics of amblyopia, strabismus, and refractive errors among patients aged 3-16 years in Shanghai, China: a hospital-based population study","volume":"24","author":"J Wu","year":"2024","journal-title":"BMC Ophthalmol"},{"key":"pone.0349697.ref002","doi-asserted-by":"crossref","first-page":"803","DOI":"10.2147\/OPTH.S354835","article-title":"Evaluation of Functional Vision and Eye-Related Quality of Life in Children with Strabismus","volume":"16","author":"N Silva","year":"2022","journal-title":"Clin Ophthalmol"},{"key":"pone.0349697.ref003","doi-asserted-by":"crossref","first-page":"97","DOI":"10.21516\/2072-0076-2017-10-2-97-102","article-title":"Amblyopia and binocular vision","volume":"10","author":"NM Maglakelidze","year":"2017","journal-title":"Russ Ophthalmol J"},{"issue":"2","key":"pone.0349697.ref004","doi-asserted-by":"crossref","first-page":"332","DOI":"10.24953\/turkjped.2020.2372","article-title":"Etiology-based strabismus classification scheme for pediatricians","volume":"64","author":"MC Mocan","year":"2022","journal-title":"Turk J Pediatr"},{"issue":"03","key":"pone.0349697.ref005","doi-asserted-by":"crossref","DOI":"10.37939\/jnah.v2i03.74","article-title":"Convergence and Accommodation Insufficiency in School Going Children","volume":"2","author":"Y Ahmed","year":"2024","journal-title":"jnah"},{"issue":"3","key":"pone.0349697.ref006","article-title":"Association between childhood strabismus and refractive error in Chinese preschool children","volume":"10","author":"H Zhu","year":"2015","journal-title":"PLoS One"},{"issue":"6","key":"pone.0349697.ref007","article-title":"Association between refractive errors and horizontal strabismus: the Korea National Health and Nutrition Examination Survey","volume":"25","author":"SH Lee","year":"2021","journal-title":"J AAPOS"},{"key":"pone.0349697.ref008","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1016\/j.ajo.2023.11.022","article-title":"Prevalence and Incidence of Strabismus by Age Group in Japan: A Nationwide Population-Based Cohort Study","volume":"262","author":"M Miyata","year":"2024","journal-title":"Am J Ophthalmol"},{"key":"pone.0349697.ref009","doi-asserted-by":"crossref","first-page":"35177","DOI":"10.1038\/srep35177","article-title":"Refractive Errors and Concomitant Strabismus: A Systematic Review and Meta-analysis","volume":"6","author":"SM Tang","year":"2016","journal-title":"Sci Rep"},{"issue":"1","key":"pone.0349697.ref010","doi-asserted-by":"crossref","first-page":"1975","DOI":"10.1186\/s12889-021-12055-2","article-title":"Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019","volume":"21","author":"Z Yang","year":"2021","journal-title":"BMC Public Health"},{"issue":"1","key":"pone.0349697.ref011","doi-asserted-by":"crossref","first-page":"13820","DOI":"10.1038\/s41598-021-93131-w","article-title":"Prevalence of strabismus and its risk factors among school aged children: The Hong Kong Children Eye Study","volume":"11","author":"XJ Zhang","year":"2021","journal-title":"Sci Rep"},{"issue":"1","key":"pone.0349697.ref012","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1080\/09286580490907805","article-title":"The prevalence of strabismus and amblyopia in Japanese elementary school children","volume":"12","author":"T Matsuo","year":"2005","journal-title":"Ophthalmic Epidemiol"},{"key":"pone.0349697.ref013","doi-asserted-by":"crossref","first-page":"33","DOI":"10.33545\/26638266.2025.v7.i2a.246","article-title":"Refractive error in primary school aged children","volume":"7","author":"MAS Almasoud","year":"2025","journal-title":"Int J Med Ophthalmol"},{"issue":"1","key":"pone.0349697.ref014","doi-asserted-by":"crossref","first-page":"100534","DOI":"10.1016\/j.optom.2024.100534","article-title":"Prevalence of refractive errors among school students in Iraq - A systematic review and meta-analysis","volume":"18","author":"HA Aljaberi","year":"2025","journal-title":"J Optom"},{"key":"pone.0349697.ref015","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/08164622.2025.2589400","article-title":"Correlation between axial length and refractive error in emmetropic and myopic Iraqi adults","author":"HA Aljaberi","year":"2025","journal-title":"Clin Exp Optom"},{"key":"pone.0349697.ref016","doi-asserted-by":"crossref","DOI":"10.1186\/s12886-025-04162-0","article-title":"Correlation between refractive errors and ocular biometric parameters at Al-Mustaqbal University, Iraq","volume":"25","author":"HA Aljaberi","year":"2025","journal-title":"BMC Ophthalmol"},{"key":"pone.0349697.ref017","first-page":"43","article-title":"Prevalence of strabismus among patients attending Basrah Teaching Hospital, Basrah, Iraq","volume":"21","author":"MA Al Ashoor","year":"2025","journal-title":"Al-Anbar Med J"},{"issue":"5","key":"pone.0349697.ref018","doi-asserted-by":"crossref","first-page":"509","DOI":"10.5958\/0976-5506.2019.01055.6","article-title":"Association between Strabismus and refractive Errors among Preschool children in Fallujah, Iraq","volume":"10","author":"NH Abady","year":"2019","journal-title":"Ind Jour of Publ Health Rese & Develop"},{"issue":"1","key":"pone.0349697.ref019","doi-asserted-by":"crossref","DOI":"10.2174\/18743641-v17-e230214-2022-36","article-title":"Contact Lens as Drug Delivery System for Glaucoma Treatment: A Review","volume":"17","author":"HA Aljaberi","year":"2023","journal-title":"TOOPHTJ"},{"issue":"5","key":"pone.0349697.ref020","doi-asserted-by":"crossref","first-page":"102441","DOI":"10.1016\/j.clae.2025.102441","article-title":"Effect of soft contact lens wear on corneal endothelial cell characteristics","volume":"48","author":"HA Aljaberi","year":"2025","journal-title":"Cont Lens Anterior Eye"},{"key":"pone.0349697.ref021","article-title":"Prevalence and Associated Risk Factors of Visual Impairment among Children at Ibn Al-Haitham Eye Hospital in Baghdad,Iraq: A Cross-sectional Study","author":"BJ Shamran","year":"2025","journal-title":"JCDR"},{"issue":"7","key":"pone.0349697.ref022","doi-asserted-by":"crossref","first-page":"1130","DOI":"10.21037\/tp-24-70","article-title":"Characteristics of astigmatism in school-age children aged 5 to 13 years in northeast Sichuan: a cross-sectional school-based study","volume":"13","author":"Y Wang","year":"2024","journal-title":"Transl Pediatr"},{"key":"pone.0349697.ref023","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1001\/jamaophthalmol.2025.0205","article-title":"Prevalence and Severity of Astigmatism in Children After COVID-19","volume":"143","author":"KW Kam","year":"2025","journal-title":"JAMA Ophthalmol"},{"key":"pone.0349697.ref024","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.ajo.2024.06.021","article-title":"Inter-Ocular Fixation Instability of Amblyopia: Relationship to Visual Acuity, Strabismus, Nystagmus, Stereopsis, Vergence, and Age","volume":"267","author":"F Ghasia","year":"2024","journal-title":"Am J Ophthalmol"},{"issue":"9","key":"pone.0349697.ref025","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1136\/bjophthalmol-2020-316406","article-title":"What can anisometropia tell us about eye growth?","volume":"105","author":"I Flitcroft","year":"2021","journal-title":"Br J Ophthalmol"},{"key":"pone.0349697.ref026","first-page":"259","article-title":"Association of horizontal strabismus and refractive errors for children in Baghdad, Iraq","volume":"4","author":"AR Noori","year":"2024","journal-title":"Med Sci J Adv Res"},{"issue":"3","key":"pone.0349697.ref027","doi-asserted-by":"crossref","first-page":"177","DOI":"10.31185\/jwsm.402","article-title":"Prevalence of refractive errors and eye disorders among primary school children in Al-Kut City, Wasit Governorate, Iraq","volume":"7","author":"Hnoosh Hussien Adnan Hussien","year":"2014","journal-title":"JWSM"},{"key":"pone.0349697.ref028","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1016\/j.ophtha.2011.06.043","article-title":"Optical treatment of strabismic and combined strabismic-anisometropic amblyopia","volume":"119","author":"SA Cotter","year":"2012","journal-title":"Ophthalmology"},{"key":"pone.0349697.ref029","doi-asserted-by":"crossref","first-page":"3409","DOI":"10.2147\/OPTH.S546692","article-title":"Estimating the Prevalence and Severity of Isolated Small-Angle Strabismic Amblyopia","volume":"19","author":"RW Arnold","year":"2025","journal-title":"Clin Ophthalmol"},{"issue":"4","key":"pone.0349697.ref030","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1080\/09286580600719055","article-title":"The multi-ethnic pediatric eye disease study: design and methods","volume":"13","author":"R Varma","year":"2006","journal-title":"Ophthalmic Epidemiol"},{"key":"pone.0349697.ref031","first-page":"129","article-title":"Distribution Pattern of Refractive Errors in Strabismic Iranian Children","volume":"17","author":"H Kangari","year":"2023","journal-title":"J Mod Rehabil"},{"issue":"2","key":"pone.0349697.ref032","doi-asserted-by":"crossref","first-page":"352","DOI":"10.18240\/ijo.2022.02.24","article-title":"Amblyopia screening for first and second-grade children in Jordan","volume":"15","author":"KM Al-Salem","year":"2022","journal-title":"Int J Ophthalmol"},{"issue":"2","key":"pone.0349697.ref033","doi-asserted-by":"crossref","first-page":"341","DOI":"10.24953\/turkjped.2021.204","article-title":"Non-ocular risk factors in Turkish children with strabismus and amblyopia","volume":"64","author":"B \u00c7ak\u0131r","year":"2022","journal-title":"Turk J Pediatr"},{"issue":"5","key":"pone.0349697.ref034","doi-asserted-by":"crossref","DOI":"10.1016\/j.jaapos.2023.07.005","article-title":"Refractive change in pediatric patients with intermittent exotropia","volume":"27","author":"O Oruz","year":"2023","journal-title":"J AAPOS"},{"key":"pone.0349697.ref035","first-page":"3","article-title":"The prevalence of amblyopia and strabismus among schoolchildren in Northeastern Iran, 2011","volume":"24","author":"AA Yekta","year":"2012","journal-title":"Iran J Ophthalmol"},{"issue":"1","key":"pone.0349697.ref036","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.joco.2017.08.009","article-title":"Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis","volume":"30","author":"H Hashemi","year":"2017","journal-title":"J Curr Ophthalmol"},{"key":"pone.0349697.ref037","article-title":"Refractive Profile and Angle of Deviation in Patients with Congenital Esotropia and Congenital Exotropia","volume":"20","author":"M Khorrami-Nejad","year":"2025","journal-title":"J Ophthalmic Vis Res"},{"issue":"3","key":"pone.0349697.ref038","doi-asserted-by":"crossref","first-page":"158","DOI":"10.4103\/2230-8229.163031","article-title":"A clinic-based study of refractive errors, strabismus, and amblyopia in pediatric age-group","volume":"22","author":"ER Al-Tamimi","year":"2015","journal-title":"J Family Community Med"},{"issue":"1","key":"pone.0349697.ref039","doi-asserted-by":"crossref","first-page":"30","DOI":"10.4103\/1319-4534.301297","article-title":"The prevalence of refractive errors among Saudi adults in Riyadh, Saudi Arabia","volume":"34","author":"T Almudhaiyan","year":"2020","journal-title":"Saudi J Ophthalmol"},{"key":"pone.0349697.ref040","doi-asserted-by":"crossref","first-page":"86","DOI":"10.4103\/0974-9233.148355","article-title":"Prevalence of amblyopia in primary school children in Qassim province, Kingdom of Saudi Arabia","volume":"22","author":"YH Aldebasi","year":"2015","journal-title":"Middle East Afr J Ophthalmol"},{"issue":"6","key":"pone.0349697.ref041","doi-asserted-by":"crossref","first-page":"180","DOI":"10.54352\/dozv.SOGH7784","article-title":"Einfluss des Astigmatismus auf die Stereopsis","volume":"5","author":"T H\u00fcbner","year":"2025","journal-title":"Optom Contact Lenses"},{"key":"pone.0349697.ref042","doi-asserted-by":"crossref","first-page":"1457297","DOI":"10.3389\/fnins.2024.1457297","article-title":"Meridional anisotropy in contrast sensitivity and visual evoked potential in adults with high myopic astigmatism","volume":"18","author":"SSA Wu","year":"2025","journal-title":"Front Neurosci"},{"issue":"44","key":"pone.0349697.ref043","doi-asserted-by":"crossref","DOI":"10.1097\/MD.0000000000040205","article-title":"Study on the impact of refractive anisometropia on strabismus, stereopsis, and amblyopia in children","volume":"103","author":"S Qiao","year":"2024","journal-title":"Medicine (Baltimore)"},{"issue":"1","key":"pone.0349697.ref044","doi-asserted-by":"crossref","first-page":"17473","DOI":"10.1038\/s41598-025-01309-3","article-title":"Correlation between binocular vision function and visual fatigue in school-age children with myopic anisometropia","volume":"15","author":"Y Cao","year":"2025","journal-title":"Sci Rep"},{"issue":"1","key":"pone.0349697.ref045","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1080\/09273972.2025.2551059","article-title":"Evidence for hypermetropia, astigmatism, and anisometropia associated with, and early glasses preventing, the development of amblyopia and accommodative esotropia","volume":"34","author":"JS Steltman","year":"2026","journal-title":"Strabismus"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0349697","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T17:29:17Z","timestamp":1779902957000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0349697"}},"subtitle":[],"editor":[{"given":"Liat","family":"Gantz","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,5,27]]},"references-count":45,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,5,27]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0349697","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,27]]}}}