title: Refractive Errors and Concomitant Strabismus: A Systematic Review and Meta-analysis.
abstract: This systematic review and meta-analysis is to evaluate the risk of development of concomitant strabismus due to refractive errors. Eligible studies published from 1946 to April 1, 2016 were identified from MEDLINE and EMBASE that evaluated any kinds of refractive errors (myopia, hyperopia, astigmatism and anisometropia) as an independent factor for concomitant exotropia and concomitant esotropia. Totally 5065 published records were retrieved for screening, 157 of them eligible for detailed evaluation. Finally 7 population-based studies involving 23,541 study subjects met our criteria for meta-analysis. The combined OR showed that myopia was a risk factor for exotropia (OR: 5.23, P = 0.0001). We found hyperopia had a dose-related effect for esotropia (OR for a spherical equivalent [SE] of 2-3 diopters [D]: 10.16, P = 0.01; OR for an SE of 3-4D: 17.83, P < 0.0001; OR for an SE of 4-5D: 41.01, P < 0.0001; OR for an SE of ≥5D: 162.68, P < 0.0001). Sensitivity analysis indicated our results were robust. Results of this study confirmed myopia as a risk for concomitant exotropia and identified a dose-related effect for hyperopia as a risk of concomitant esotropia.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Shu Min
authors.initials: SM
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Rachel Y T
authors.initials: RY
authors.lastname: Chan
authors.affiliation: Joint Shantou International Eye Center, Shantou University and The Chinese University of Hong Kong, Shantou, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Bin Lin
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Shi Song
authors.initials: SS
authors.lastname: Rong
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Henry H W
authors.initials: HH
authors.lastname: Lau
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Winnie W Y
authors.initials: WW
authors.lastname: Lau
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Wilson W K
authors.initials: WW
authors.lastname: Yip
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.|Joint Shantou International Eye Center, Shantou University and The Chinese University of Hong Kong, Shantou, China.
authors.forename: Li Jia
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Tung Wah Eastern Hospital, Hong Kong.
authors.forename: Simon T C
authors.initials: ST
authors.lastname: Ko
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.|Joint Shantou International Eye Center, Shantou University and The Chinese University of Hong Kong, Shantou, China.
authors.forename: Jason C S
authors.initials: JC
authors.lastname: Yam
mesh_terms: D015858:Anisometropia / Q000150:complications; D001251:Astigmatism / Q000150:complications; D002648:Child; D003430:Cross-Sectional Studies; D004948:Esotropia / Q000209:etiology; D005099:Exotropia / Q000209:etiology; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000150:complications; D008297:Male; D009216:Myopia / Q000150:complications; D016017:Odds Ratio; D012030:Refractive Errors / Q000150:complications*; D012307:Risk Factors; D013285:Strabismus / Q000209:etiology*