© 2017 Wichtg Publishing EJO ISSN 1120-6721 Eur J Ophthalmol 2017; 00 (00): 000-000 ORIGINAL RESEARCH ARTICLE diferent prevalence rates according to the country and the criteria used in diagnosis (2). Since amblyopia is the efect of a pathologic process, recent studies propose to include in its diagnosis not only acuity-based criteria, but also the concomi- tant presence of causal factors, called amblyogenic risk fac- tors (ARF) (3, 4). Functonal eye anomalies, such as refractve error, strabismus, and media opacity, are established ARF (5). Amblyopia is regarded as an important public health problem as it is the main cause of vision loss in children and one of the leading causes of visual impairment in adults (6, 7). The prompt detecton and treatment of amblyopia could pre- vent or cure this consequence (8, 9). Therefore, this pediatric ophthalmologic screening topic, in order to detect decrease in visual acuity and/or ARF, has gained widespread aten- ton in recent decades. Also, it seems that screening high-risk DOI: 10.5301/ejo.5001036 New pediatric risk factors for amblyopia: strabismic versus refractve Sandra Guimaraes 1-3 , Maria Vieira 4 , Tatana Queirós 1 , Andreia Soares 1 , Patrício Costa 2,3,5 , Eduardo Silva 6-8 1 Department of Ophthalmology, Hospital de Braga, Braga - Portugal 2 Life and Health Sciences Research Insttute (ICVS), School of Medicine, University of Minho, Braga - Portugal 3 ICVS/3Bs, PT Government Associate Laboratory, Braga/Guimarães - Portugal 4 School of Medicine, University of Minho, Braga - Portugal 5 Clinical Academic Center-Braga, Braga - Portugal 6 Department of Ophthalmology, Centro Cirurgico de Coimbra, Coimbra - Portugal 7 IBILI, Faculty of Medicine, University of Coimbra, Coimbra - Portugal 8 Department of Ophthalmology, CHLN, Lisbon - Portugal Sandra Guimaraes and Maria Vieira contributed equally to this work. Introducton Amblyopia is a neurodevelopmental vision disorder caused by sensory defcits during early life (1). It is a common ophthalmologic disorder in pediatric age, with considerably AbSTRACT Purpose: To assess the role of risk factors for amblyopia, such as family history and neonatal background, for the predicton of either strabismic amblyopia or refractve amblyopia. Methods: In this retrospectve case-control model, the study populaton included all children born at the Hospi- tal de Braga during 1997-2012 (3 to 18 years old) with ophthalmologic consultaton in 2014. Data collecton was performed from the clinical database and through telephone questonnaire surveys. Results: A total of 298 (50%) controls and 298 (50%) cases (120 [40.3%] strabismic amblyopia and 178 [59.7%] refractve amblyopia) were analyzed. A signifcantly lower birthweight was detected in patents with strabismic amblyopia (mean 2,961 g [95% confdence interval (CI) 2,827-3,096]) compared to controls (mean 3,198 g [95% CI 3,125-3,271]) (p = 0.002). Five-minute Apgar was signifcantly lower in patents with strabismic amblyopia (mean 9.57 [95% CI 9.37-9.77]) than in controls (mean 9.83 [95% CI 9.77-9.90]) (p = 0.004) or patents with refractve amblyopia (mean 9.79 [95% CI 9.69-9.89]) (p = 0.031). Family history of either amblyopia or strabismus was as- sociated with amblyopia (χ 2 [2, n = 562] = 12.66; p = 0.002; Cramer V = 0.150; χ 2 [2, n = 561] = 11.0; p = 0.004; Cra- mer V = 0.140), but was signifcantly more associated with strabismic amblyopia (p = 0.0023 and p = 0.0032) than with refractve amblyopia (p = 0.48 and p = 0.015, respectvely). Multnomial logistc regression model explained 50.8% of the variance in amblyopia development. Low 5-minute Apgar had a relevant odds rato (OR) for either strabismic amblyopia (OR 3.44; p = 0.066) or refractve amblyopia (OR 3.30; p = 0.077). Conclusions: This division in amblyopia subtypes gives a new perspectve of the risk factors for amblyopia, with family history and some obstetrician/neonatal outcomes appearing to be more relevant in strabismic am- blyopia. Educatng health care providers to recognize these risk factors can result in an early ophthalmologic referral. Keywords: Amblyogenic risk factors, Family history, Neonatal background Accepted: August 23, 2017 Published online: September 11, 2017 Corresponding author: Sandra Guimaraes Department of Ophthalmology Hospital de Braga, Braga, Portugal sandraguimaraes.eye@gmail.com