PURPOSE: The purpose of this study was to measure near heterophoria in young children to determine the impact of early growth and development on the alignment of the eyes. METHODS: Fifty young children (≥2 and <7 years of age; range of spherical equivalent refractive error -1.25 diopters [D] to +3.75 D) and 13 adults participated. Their eye position and accommodation responses, in the absence of optical correction, were measured using simultaneous Purkinje image tracking and photorefraction technology (MCS PowerRefractor, PR). The resulting heterophorias, and both accommodative convergence/accommodation (AC/A) and convergence accommodation/convergence (CA/C) ratios were then computed as a function of age, refractive error, and an alternating cover test. RESULTS: The mean heterophoria after approximately 60 seconds of dissociation at a 33-cm viewing distance was 5.0 prism diopters (pd) of exophoria (SD ± 3.7) in the children (78% of children > 2 pd exophoric) and 5.6 pd of exophoria (SD ± 4.7) in adults (69% of adults > 2pd exophoric; a nonsignificant difference), with no effect of age between 2 and 6 years. In these children, heterophoria was not significantly correlated with AC/A (r = 0.25), CA/C (r = 0.12), or refractive error (r = 0.21). The mean difference between heterophoria measurements from the PR and the clinical cover test was -2.4 pd (SD = ±3.4), with an exophoric bias in the PR measurements. CONCLUSIONS: Despite developmental maturation of interpupillary distance, refractive error, and AC/A, in a typical sample of young children the predominant dissociated position is one of exophoria. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: The purpose of this study was to measure near heterophoria in young children to determine the impact of early growth and development on the alignment of the eyes. METHODS: Fifty young children (≥2 and <7 years of age; range of spherical equivalent refractive error -1.25 diopters [D] to +3.75 D) and 13 adults participated. Their eye position and accommodation responses, in the absence of optical correction, were measured using simultaneous Purkinje image tracking and photorefraction technology (MCS PowerRefractor, PR). The resulting heterophorias, and both accommodative convergence/accommodation (AC/A) and convergence accommodation/convergence (CA/C) ratios were then computed as a function of age, refractive error, and an alternating cover test. RESULTS: The mean heterophoria after approximately 60 seconds of dissociation at a 33-cm viewing distance was 5.0 prism diopters (pd) of exophoria (SD ± 3.7) in the children (78% of children > 2 pd exophoric) and 5.6 pd of exophoria (SD ± 4.7) in adults (69% of adults > 2pd exophoric; a nonsignificant difference), with no effect of age between 2 and 6 years. In these children, heterophoria was not significantly correlated with AC/A (r = 0.25), CA/C (r = 0.12), or refractive error (r = 0.21). The mean difference between heterophoria measurements from the PR and the clinical cover test was -2.4 pd (SD = ±3.4), with an exophoric bias in the PR measurements. CONCLUSIONS: Despite developmental maturation of interpupillary distance, refractive error, and AC/A, in a typical sample of young children the predominant dissociated position is one of exophoria. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
Entities:
Keywords:
accommodation; heterophoria; refractive error; vergence; young children
Authors: Sang J Han; Yi Guo; Bérangère Granger-Donetti; Vincent R Vicci; Tara L Alvarez Journal: Ophthalmic Physiol Opt Date: 2009-08-13 Impact factor: 3.117
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Authors: Elena Pinero-Pinto; Verónica Pérez-Cabezas; Concepción De-Hita-Cantalejo; Carmen Ruiz-Molinero; Estanislao Gutiérrez-Sánchez; José-Jesús Jiménez-Rejano; José-María Sánchez-González; María Carmen Sánchez-González Journal: Int J Environ Res Public Health Date: 2020-05-20 Impact factor: 3.390