PURPOSE: To evaluate parameters associated with astigmatism axis orientation. METHODS: A retrospective population-based study was conducted on 67,899 (53% males) Israeli Defense Force conscripts aged 16 to 22 years with >or=0.25 D of astigmatism, using prerecruitment examination and demographic data that included a validated general intelligence score. Refractive errors were classified by the cylinder axis with the least deviation from emmetropia (LDE), a scheme intended to avoid confounding spherical classification by cylinder power. Perinatal photoperiod was determined from birth date and astronomical tables. RESULTS: With-the-rule (WTR) axis was associated with higher LDE (P < 0.001), higher cylinder power (P < 0.001), Eastern or Western compared with Israeli origin (P < 0.001), higher body mass index (P < 0.001), lower intelligence scores (P < 0.001), and longer perinatal photoperiod (P < 0.001), using univariate analysis. Multivariate logistic regression confirmed the independent association of these parameters and identified being of the female sex as another WTR axis association. Subjects' cylinder axis also was associated with their siblings' cylinder axis (odds ratio [OR] = 1.58; 95% confidence interval [CI] = 1.31-1.90), using siblings' refractive data for the 3852 available subjects in the regression model. However, the associations of these parameters with WTR, against-the-rule, or oblique astigmatism were neither parallel as a whole nor parallel between any two sets of axis orientations. Further, the directions of the associations of these parameters with astigmatism axis and power did not consistently conform to their previously reported associations for spherical ametropias. CONCLUSIONS: The results suggest both that distinctive mechanisms may account for the different astigmatism axis orientations and that mechanisms influencing astigmatism development are likely to vary from those governing the spherical component of refraction.
PURPOSE: To evaluate parameters associated with astigmatism axis orientation. METHODS: A retrospective population-based study was conducted on 67,899 (53% males) Israeli Defense Force conscripts aged 16 to 22 years with >or=0.25 D of astigmatism, using prerecruitment examination and demographic data that included a validated general intelligence score. Refractive errors were classified by the cylinder axis with the least deviation from emmetropia (LDE), a scheme intended to avoid confounding spherical classification by cylinder power. Perinatal photoperiod was determined from birth date and astronomical tables. RESULTS: With-the-rule (WTR) axis was associated with higher LDE (P < 0.001), higher cylinder power (P < 0.001), Eastern or Western compared with Israeli origin (P < 0.001), higher body mass index (P < 0.001), lower intelligence scores (P < 0.001), and longer perinatal photoperiod (P < 0.001), using univariate analysis. Multivariate logistic regression confirmed the independent association of these parameters and identified being of the female sex as another WTR axis association. Subjects' cylinder axis also was associated with their siblings' cylinder axis (odds ratio [OR] = 1.58; 95% confidence interval [CI] = 1.31-1.90), using siblings' refractive data for the 3852 available subjects in the regression model. However, the associations of these parameters with WTR, against-the-rule, or oblique astigmatism were neither parallel as a whole nor parallel between any two sets of axis orientations. Further, the directions of the associations of these parameters with astigmatism axis and power did not consistently conform to their previously reported associations for spherical ametropias. CONCLUSIONS: The results suggest both that distinctive mechanisms may account for the different astigmatism axis orientations and that mechanisms influencing astigmatism development are likely to vary from those governing the spherical component of refraction.
Authors: Qing Li; Robert Wojciechowski; Claire L Simpson; Pirro G Hysi; Virginie J M Verhoeven; Mohammad Kamran Ikram; René Höhn; Veronique Vitart; Alex W Hewitt; Konrad Oexle; Kari-Matti Mäkelä; Stuart MacGregor; Mario Pirastu; Qiao Fan; Ching-Yu Cheng; Beaté St Pourcain; George McMahon; John P Kemp; Kate Northstone; Jugnoo S Rahi; Phillippa M Cumberland; Nicholas G Martin; Paul G Sanfilippo; Yi Lu; Ya Xing Wang; Caroline Hayward; Ozren Polašek; Harry Campbell; Goran Bencic; Alan F Wright; Juho Wedenoja; Tanja Zeller; Arne Schillert; Alireza Mirshahi; Karl Lackner; Shea Ping Yip; Maurice K H Yap; Janina S Ried; Christian Gieger; Federico Murgia; James F Wilson; Brian Fleck; Seyhan Yazar; Johannes R Vingerling; Albert Hofman; André Uitterlinden; Fernando Rivadeneira; Najaf Amin; Lennart Karssen; Ben A Oostra; Xin Zhou; Yik-Ying Teo; E Shyong Tai; Eranga Vithana; Veluchamy Barathi; Yingfeng Zheng; Rosalynn Grace Siantar; Kumari Neelam; Youchan Shin; Janice Lam; Ekaterina Yonova-Doing; Cristina Venturini; S Mohsen Hosseini; Hoi-Suen Wong; Terho Lehtimäki; Mika Kähönen; Olli Raitakari; Nicholas J Timpson; David M Evans; Chiea-Chuen Khor; Tin Aung; Terri L Young; Paul Mitchell; Barbara Klein; Cornelia M van Duijn; Thomas Meitinger; Jost B Jonas; Paul N Baird; David A Mackey; Tien Yin Wong; Seang-Mei Saw; Olavi Pärssinen; Dwight Stambolian; Christopher J Hammond; Caroline C W Klaver; Cathy Williams; Andrew D Paterson; Joan E Bailey-Wilson; Jeremy A Guggenheim Journal: Hum Genet Date: 2014-11-04 Impact factor: 4.132