Risk factors for astigmatism in preschool children: the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.

OBJECTIVE: To evaluate risk factors for astigmatism in a population-based sample of preschool children. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Population-based samples of 9970 children ages 6 to 72 months from Los Angeles County, California, and Baltimore, Maryland. METHODS: A cross-sectional study of children participating in the Multiethnic Pediatric Eye Disease Study and the Baltimore Eye Disease Study was completed. Data were obtained by clinical examination or by in-person interview. Odds ratios and 95% confidence intervals (CI) were calculated to evaluate potential associations between clinical, behavioral, or demographic factors and astigmatism. MAIN OUTCOME MEASURES: Odds ratios (ORs) for various risk factors associated with astigmatism. RESULTS: Participants with myopia (≤-1.0 diopters) were 4.6 times as likely to have astigmatism (95% CI, 3.56-5.96) than those without refractive error, whereas participants with hyperopia (≥+2.00 diopters) were 1.6 times as likely (95% CI, 1.39-1.94). Children 6 to <12 months of age were approximately 3 times as likely to have astigmatism than children 5 to 6 years of age (95% CI, 2.28-3.73). Both Hispanic (OR, 2.38) and African-American (OR, 1.47) children were as likely to have astigmatism than non-Hispanic white children. Furthermore, children whose mothers smoked during pregnancy were 1.46 times (95% CI, 1.14-1.87) as likely to have astigmatism than children whose mothers did not smoke. CONCLUSIONS: In addition to infancy, Hispanic and African-American race/ethnicity and correctable/modifiable risk factors such as myopia, hyperopia, and maternal smoking during pregnancy are associated with a higher risk of having astigmatism. Although the prevalence of smoking during pregnancy is typically low, this association may suggest etiologic pathways for future investigation. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Risk factors for decreased visual acuity in preschool children: the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.

OBJECTIVE: To investigate risk factors associated with unilateral or bilateral decreased visual acuity (VA) in preschool children. DESIGN: Population-based, cross-sectional prevalence study. PARTICIPANTS: Population-based samples of 6504 children ages 30 to 72 months from California and Maryland. METHODS: Participants were preschool African-American, Hispanic, and non-Hispanic white children from Los Angeles, California, and Baltimore, Maryland. Data were obtained by a parental interview and a detailed ocular examination. Logistic regression models were used to evaluate the independent associations between demographic, behavioral, and clinical risk factors with unilateral and bilateral decreased VA. MAIN OUTCOME MEASURES: Odds ratios (ORs) for various risk factors associated with interocular difference (IOD) in VA of ≥2 lines with ≤20/32 in the worse eye, or bilateral decreased VA <20/40 or <20/50 if <48 months of age. RESULTS: In multivariate logistic regression analysis, 2-line IOD with a VA of ≤20/32 was independently associated with Hispanic ethnicity (OR, 2.05), esotropia (OR, 8.98), spherical equivalent (SE) anisometropia (ORs ranging between 1.5 and 39.7 for SE anisometropia ranging between 0.50 to <1.00 diopters [D] and ≥2.00 D), and aniso-astigmatism in J0 or J45 (ORs ranging between 1.4 and ≥5.3 for J0 or J45 differences ranging between 0.25 to <0.50 D and ≥1.00 D). Bilateral decreased VA was independently associated with lack of health insurance (OR, 2.9), lower primary caregiver education (OR, 1.7), astigmatism (OR, 2.3 and 17.6 for astigmatism 1.00 to <2.00 D and ≥2.00 D), and SE hyperopia ≥4.00 D (OR, 10.8). CONCLUSIONS: Anisometropia and esotropia are risk factors for IOD in VA. Astigmatism and high hyperopia are risk factors for bilateral decreased VA. Guidelines for the screening and management of decreased VA in preschool children should be considered in light of these risk associations. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Risk factors for hyperopia and myopia in preschool children the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.

PURPOSE: To describe the risk factors associated with hyperopia and myopia among children 6 to 72 months of age. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Population-based samples of 9970 children 6 to 72 months of age from Los Angeles County, California, and Baltimore, Maryland. METHODS: Participants were preschool African-American, Hispanic, and non-Hispanic white children (n = 9770) from Los Angeles, California, and Baltimore, Maryland. Parental questionnaires and a comprehensive eye examination were administered. Demographic, behavioral, and clinical risk factors associated with hyperopia (≥2.00 diopters [D]) and myopia (≤-1.00 D) were determined. MAIN OUTCOME MEASURES: Odds ratios (ORs) for risk factors associated with myopia and hyperopia. RESULTS: Compared with non-Hispanic whites, African-American (OR, 6.0) and Hispanic (OR, 3.2) children were more likely to be myopic. Children 6 to 35 months of age were more likely to be myopic compared with those 60 to 72 months of age (OR, ≥1.7). Compared with African-American children, non-Hispanic white (OR, 1.63) and Hispanic (OR, 1.49) children were more likely to be hyperopic. Children whose parents had health insurance (OR, 1.5) and those with a history of maternal smoking during pregnancy (OR, 1.4) were more likely to have hyperopia. Astigmatism of 1.5 D or more at any axis was associated with myopia (OR, 4.37) and hyperopia (OR, 1.43). CONCLUSIONS: Children in specific racial or ethnic groups and age groups are at higher risk of having myopia and hyperopia. Cessation of maternal smoking during pregnancy may reduce the risk of hyperopia in these children. Given that both myopia and hyperopia are risk factors for the development of amblyopia and strabismus, these risk factors should be considered when developing guidelines for screening and intervention in preschool children. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Prostaglandin H synthase 2 variant (Val511Ala) in African Americans may reduce the risk for colorectal neoplasia.

Prostaglandin H synthase 2 (also known as cyclooxygenase-2) is thought to play a role in the prevention of colon cancer by aspirin, an inhibitor of the enzyme. We used DNA heteroduplex analysis to screen the prostaglandin H synthase 2 gene, to search for naturally occurring enzyme variants that may simulate the effects of aspirin. We found among African-Americans a single-nucleotide polymorphism that changes valine to alanine at residue 511 (V511A; GTT>GCT; g.5939T>C; allele frequency 0.045). The polymorphism was also seen among Asian-Indians (allele frequency, 0.03) but not among Chinese, Filipinos, Hispanics, Japanese, Koreans, Samoans, and Caucasians. The amino acid change is predicted to open a 53 cubic angstrom cavity near the active site of the enzyme, but no change in V(max), K(m), or thermal stability was observed for the variant enzyme in COS-1 cell transfection assays. Case-control analysis of African-Americans from two different study populations showed a 0.56 odds ratio for colorectal adenomas among polymorphism carriers (95% confidence interval, 0.25-1.27; 161 cases and 219 controls). A similar analysis of African-Americans nested in the Multiethnic Cohort Study showed a 0.67 odds ratio for colorectal cancer (95% confidence interval, 0.28-1.56; 138 cases and 258 controls). Consistency of the results across all three of the studies is potentially compatible with a protective effect of the polymorphism, mimicking aspirin.