Enantiomorphism and rule similarity in the astigmatism axes of fellow eyes: A population-based study

Hashemi, H. and Asharlous, A. and Yekta, A. and Ostadimoghaddam, H. and Mohebi, M. and Aghamirsalim, M. and Khabazkhoob, M. (2019) Enantiomorphism and rule similarity in the astigmatism axes of fellow eyes: A population-based study. Journal of Optometry, 12 (1). pp. 44-54.

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Purpose: To evaluate the relationship patterns between astigmatism axes of fellow eyes (rule similarity and symmetry) and to determine the prevalence of each pattern in the studied population. Methods: This population-based study was conducted in 2015 in Iran. All participants had tests for visual acuity, objective refraction, subjective refraction (if cooperative), and assessment of eye health at the slit-lamp. Axis symmetry was based on two different patterns: direct (equal axes) and mirror (mirror image symmetry) or enantiomorphism. Bilateral astigmatism was classified as isorule if fellow eyes had the same orientation (e.g. both eyes were with-the-rule) and as anisorule if otherwise. Results: Of the total cases of bilateral astigmatism, 80 were isorule, and in the studied population, the prevalence of isorule and anisorule astigmatism was 14.89 and 3.53, respectively. The prevalence of isorule increased with age (p < 0.001). The prevalence of both isorule and anisorule increased at higher degrees of spherical ametropia (p < 0.001). Median inter-ocular axis difference was 10° in mirror symmetry and 20° in direct symmetry with no significant difference between two genders (p > 0.288). Both symmetry patterns reduced with age (p < 0.001). Among cases of bilateral astigmatism, 15.5 and 19.8 had exact direct and mirror symmetry, respectively. Conclusion: Bilateral astigmatism is mainly isorule in the population and anisorule astigmatism is rare. The enantiomorphism is the most common pattern in the population of bilateral astigmatism. © 2018 Spanish General Council of Optometry

Item Type: Article
Additional Information: Cited By :1 Export Date: 16 February 2020 Correspondence Address: Khabazkhoob, M.; Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical SciencesIran; email: Khabazkhoob@yahoo.com
Uncontrolled Keywords: Anisorule Astigmatism Direct symmetry Isorule Mirror symmetry adolescent adult aged child cross-sectional study female human Iran male middle aged preschool child prevalence refraction error visual acuity young adult Child, Preschool Cross-Sectional Studies Humans Refractive Errors
Subjects: WW Ophthalmology
Divisions: Mashhad University of Medical Sciences
Depositing User: mr lib1 lib1
Date Deposited: 21 Jun 2020 06:32
Last Modified: 21 Jun 2020 06:32
URI: http://eprints.mums.ac.ir/id/eprint/18386

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