Prevalence of Heterophoria and Associations with Refractive Error, Heterotropia and Ethnicity in Australian School Children

Date

2010

Authors

Leone, Jody F
Cornell, Elaine
Morgan, Ian
Mitchell, Paul
Kifley, Annette
Wang, Jie Jin
Rose, Kathryn A

Journal Title

Journal ISSN

Volume Title

Publisher

BMJ Publishing Group

Abstract

Aims: To establish the prevalence of heterophoria and its association with refractive error and ethnicity in a population-based study of Australian schoolchildren. Methods: The Sydney Myopia Study is a stratified, random cluster (school-based) sample of 4093 students (examined: 2003e2005). Two samples aged 6 (n=1692) and 12 years (n=2289) without heterotropia were included. Prevalent heterophoria was assessed using cover un-cover and prism bar alternate cover testing at 33 cm and 6 m distance fixation. Cycloplegic autorefraction (1% cyclopentolate) was performed. Significant refractive error was defined as ≤-0.50SE and ≥+2.00SE. Results: Exophoria was highly prevalent at near fixation (age 6: 58.3%, age 12: 52.2%). Orthophoria predominated at distance fixation (age 6: 85.4%, age 12: 90.9%). Hyperopia was associated with esophoria at near (age 6: OR 1.7, 95% CI 1.1 to 2.8, age 12: OR 2.9, CI 1.1 to 2.8) and distance fixation (age 6: OR 9.7, CI 3.5 to 26, age 12: 9.6 OR, CI 4.2 to 22). Myopia was associated with exophoria at near (OR 2.1, CI 1.5 to 2.7) and distance fixation (OR 3.1, CI 2.1 to 4.4) for 12-year-old children only. Exophoria was more frequent in children of East Asian than European Caucasian origins, even after adjusting for refraction; at near (age 6: OR 1.4, CI 1.0 to 2.0, age 12: OR 1.4, CI 1.0 to 1.9) and distance (age 12: OR 1.7, CI 1.1 to 2.7). Conclusion: Contrary to other studies, exophoria, not orthophoria, was predominant for near. Exophoria was more prevalent in children of East Asian origin. Longitudinal studies are needed to establish if incident heterotropia is preceded by heterophoria.

Description

Keywords

Keywords: accommodation paralysis; article; child; disease association; ethnicity; exophoria; eye fixation; eye movement disorder; female; heterophoria; heterotropism; human; hypermetropia; major clinical study; male; myopia; prevalence; priority journal; refractio

Citation

Source

BJO Online (British Journal of Ophthalmology Online)

Type

Journal article

Book Title

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DOI

10.1136/bjo.2009.163709

Restricted until

2037-12-31