Rasch analysis of the Student Refractive Error and Eyeglass Questionnaire.

PURPOSE: To evaluate and refine a newly developed instrument, the Student Refractive Error and Eyeglasses Questionnaire (SREEQ), designed to measure the impact of uncorrected and corrected refractive error on vision-related quality of life (VRQoL) in school-aged children. METHODS: A 38-statement instrument consisting of two parts was developed: part A relates to perceptions regarding uncorrected vision and part B relates to perceptions regarding corrected vision and includes other statements regarding VRQoL with spectacle correction. The SREEQ was administered to 200 Native American 6th- through 12th-grade students known to have previously worn and who currently require eyeglasses. Rasch analysis was conducted to evaluate the functioning of the SREEQ. Statements on parts A and B were analyzed to examine the dimensionality and constructs of the questionnaire, how well the items functioned, and the appropriateness of the response scale used. RESULTS: Rasch analysis suggested two items be eliminated and the measurement scale for matching items be reduced from a four-point response scale to a three-point response scale. With these modifications, categorical data were converted to interval-level data to conduct an item and person analysis. A shortened version of the SREEQ was constructed with these modifications, the SREEQ-R, which included the statements that were able to capture changes in VRQoL associated with spectacle wear for those with significant refractive error in our study population. CONCLUSIONS: Although part B of the SREEQ appears to have a less-than-optimal reliability to assess the impact of spectacle correction on VRQoL in our student population, it is able to detect statistically significant differences from pretest to posttest on both the group and individual levels to show that the instrument can assess the impact that glasses have on VRQoL. Further modifications to the questionnaire, such as those included in the SREEQ-R, could enhance its functionality.

Developmental changes in anterior corneal astigmatism in Tohono O'odham Native American infants and children.

UNLABELLED: ABSTRACT Purpose: To describe change in corneal astigmatism in infants and children of a Native American tribe with a high prevalence of astigmatism. METHODS: Longitudinal measurements of corneal astigmatism were obtained in 960 Tohono O'odham children aged 6 months to <8 years. Change in corneal astigmatism (magnitude (clinical notation), J0, J45) across age in children with high astigmatism (≥2 diopter (D) corneal astigmatism) or low/no astigmatism (<2 D corneal astigmatism) at their baseline measurement was assessed. RESULTS: Regression analyses indicated that early in development (6 months to <3 years), astigmatism magnitude decreased in the high astigmatism group (0.37 D/year) and remained stable in the low/no astigmatism group. In later development (3 to <8 years), astigmatism decreased in the high (0.11 D/year) and low/no astigmatism groups (0.03 D/year). In 52 children who had data at all three of the youngest ages (6 months to <1 year, 1 to <2 years, 2 to <3 years) astigmatism decreased after infancy in those with high astigmatism (p = 0.021), and then remained stable from age 1-2 years, whereas astigmatism was stable from infancy through age 1 year and increased from age 1-2 years in the low/no astigmatism group (p = 0.026). J0 results were similar, but results on J45 yielded no significant effects. CONCLUSIONS: The greatest change occurred in highly astigmatic infants and toddlers (0.37 D/year). By age 3 years, change was minimal and not clinically significant. Changes observed were due primarily to change in the J0 component of astigmatism.

Spectacle wear in children given spectacles through a school-based program.

PURPOSE: To investigate factors associated with spectacle wear in a group of primarily Native-American children provided spectacles free of charge through a school-based vision program. METHODS: Spectacle wear was studied in 247 participants provided two pairs of spectacles the previous year. Univariate and multivariate logistic regression models assessed whether gender, race, parental education levels, family income, uncorrected distance visual acuity, refractive error, or the children's attitudes and beliefs about their vision and spectacles were associated with spectacle wear. RESULTS: Two thirds of the participants (165/247) were not wearing their spectacles at their annual examination. The most common reasons given for non-wear were lost (44.9%) or broken (35.3%) spectacles. A 1 diopter increase in myopic spherical equivalent was associated with more than a twofold increase in the odds of wearing spectacles [odds ratio (OR) = 2.5, 95% confidence interval (CI) = 1.7 to 3.7]. Among non-myopic participants, increasing amounts of astigmatism in the better- and worse-seeing eye were associated with an increased likelihood of spectacle wear (p ≤ 0.02). In multivariate analysis, only poorer uncorrected acuity in the better-seeing eye (p < 0.001) and shorter acceptance time (p = 0.007) were found to be significantly associated with spectacle wear. For each line of poorer uncorrected acuity in the better-seeing eye, the likelihood that the participant was wearing spectacles increased by 60% (adjusted odds ratio = 1.6; 95% CI = 1.4 to 1.8). Not surprisingly, participants who reported never getting used to their spectacles were less likely to be wearing spectacles than those who reported getting used to wearing glasses in a few days (adjusted OR = 5.7, 95% CI = 1.9 to 17.5). CONCLUSIONS: Despite being provided with two pairs of spectacles, loss and breakage were the most commonly reported reasons for not wearing spectacles. The best predictive factor for determining whether participants were wearing spectacles was their uncorrected acuity.

Accuracy and validity of IK4 handheld video keratometer measurements in children.

The infant keratometer (IK4) is a custom handheld instrument that was designed specifically to allow measurement of corneal astigmatism in infants as young as 6 months of age. In this study, accuracy of IK4 measurements with the use of standard toric surfaces was within 0.25 D. Validity measurements obtained in 860 children aged 3-7 years demonstrated slightly greater astigmatism measurements in the IK4 than in the Retinomax K+. Measurement success was 98% when the IK4 was used. The IK4 may prove to be clinically useful for screening children as young as 3 years of age at high risk for corneal astigmatism.

Prevalence of corneal astigmatism in Tohono O'odham Native American children 6 months to 8 years of age.

PURPOSE: To describe the prevalence of corneal astigmatism in infants and young children who are members of a Native American tribe with a high prevalence of refractive astigmatism. METHODS: The prevalence of corneal astigmatism was assessed by obtaining infant keratometer (IK4) measurements from 1235 Tohono O'odham children, aged 6 months to 8 years. RESULTS: The prevalence of corneal astigmatism >2.00 D was lower in the 1- to <2-year-old age group when compared with all other age groups, except the 6- to <7-year-old group. The magnitude of mean corneal astigmatism was significantly lower in the 1- to <2-year age group than in the 5- to <6-, 6- to <7-, and 7- to <8-year age groups. Corneal astigmatism was with-the-rule (WTR) in 91.4% of astigmatic children (≥1.00 D). CONCLUSIONS: The prevalence and mean amount of corneal astigmatism were higher than reported in non-Native American populations. Mean astigmatism increased from 1.43 D in 1-year-olds to nearly 2.00 D by school age.

Prevalence of astigmatism in Native American infants and children.

PURPOSE: To describe the prevalence of high astigmatism in infants and young children who are members of a Native American tribe with a high prevalence of astigmatism. METHODS: SureSight autorefraction measurements were obtained for 1461 Tohono O'odham children aged 6 months to 8 years. RESULTS: The prevalence of astigmatism >2.00 diopters was 30% in Tohono O'odham children during infancy (6 months to <1 year of age) and was 23 to 29% at ages 2 to 7 years. However, prevalence dipped to 14% in children 1 to <2 years of age. At all ages, axis of astigmatism was with-the-rule (plus cylinder axis 90 degrees +/- 30 degrees ) in at least 94% of cases. CONCLUSIONS: As in non-Native American populations, Tohono O'odham infants show a high prevalence of astigmatism, which decreases in the second year of life. However, the prevalence of high astigmatism in Tohono O'odham children increases by age 2 to <3 years to a level near that seen in infancy and remains at that level until at least age 8 years. Longitudinal data are needed to determine whether the increase in high astigmatism after infancy occurs in infants who had astigmatism as infants or is due to the development of high astigmatism in children who did not show astigmatism during infancy.

Prevalence of strabismus among preschool, kindergarten, and first-grade Tohono O'odham children.

BACKGROUND: Although the prevalence of strabismus is 2% to 5% in European-based and African-American populations, little is known about the prevalence of strabismus in Native-American populations. We report the prevalence of strabismus in children who are members of a Native-American tribe with a high prevalence of astigmatism. METHODS: Subjects were 594 children enrolled in Head Start and 315 children enrolled in kindergarten or first grade (K/1) in schools on the Tohono O'odham Reservation. Distance and near cover tests were performed on each child by an ophthalmologist or optometrist, and cycloplegic refraction was obtained. RESULTS: Strabismus was detected in 9 Head Start children (1.5%) and 3 K/1 children (1.0%). Ratio of esotropia to exotropia was 1:3 in Head Start and 1:2 in K/1. Anisometropia >or=1.00 diopter (D) spherical equivalent was present in 2 children with strabismus, and anisometropia >or=1.00 D cylinder was present in 4 with strabismus. CONCLUSION: The prevalence of strabismus in Tohono O'odham children is at the low end of the prevalence range reported in studies of European-based and African-American populations.

Accuracy of the Welch Allyn SureSight for measurement of magnitude of astigmatism in 3- to 7-year-old children.

PURPOSE: To evaluate the accuracy of the Welch Allyn SureSight in noncycloplegic measurements of astigmatism as compared to cycloplegic Retinomax K+ autorefractor measurements of astigmatism in children from a Native American population with a high prevalence of high astigmatism. METHODS: Data are reported for 825 3- to 7-year-old children with no ocular abnormalities. Each child had a Retinomax K+ cycloplegic measurement of right eye astigmatism with a confidence rating > or =8 and 3 attempts to obtain a SureSight measurement on the right eye. RESULTS: SureSight measurement success rates did not differ significantly across age or measurement confidence rating (<6 vs > or =6). Ninety-six percent of children had at least 1 measurement (any confidence), and 89% had at least 1 measurement with confidence at the manufacturer's recommended value (> or =6). Overall, the SureSight tended to overestimate astigmatism. If the SureSight measurement had any dioptric value (0.00 D to 3.00 D), astigmatism of 2.00 D or less was likely to be present. If the SureSight showed astigmatism beyond the instrument's dioptric range (>3.00 D), Retinomax K+ measurements indicated that >2.00 D of astigmatism was present in 136 of 157 (86.6%). In cooperative children for whom the SureSight would not give a reading, 32 of 34 (94%) had >3.00 D of astigmatism. CONCLUSIONS: The SureSight does not provide an accurate, quantitative measure of amount of astigmatism. However, it does allow accurate categorization of amount of astigmatism as < or =2.00 D, >2.00 D, or >3.00 D, and it has high measurement success rate in young children.

Children's Ocular Components and Age, Gender, and Ethnicity.

PURPOSE: This cross-sectional report includes ocular component data as a function of age, gender, and ethnicity from the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. METHODS: The ocular components of 4881 school-aged children were examined using cycloplegic autorefraction (refractive error), keratometry (corneal curvature), ultrasonography (axial dimensions), and videophakometry (lens curvature). RESULTS: The average age (+/-SD) was 8.8 +/- 2.3 years, and 2457 were girls (50.3%). Sixteen percent were African-American, 14.8% were Asian, 22.9% were Hispanic, 11.6% were Native American, and 34.9% were White. More myopic/less hyperopic refractive error was associated with greater age, especially in Asians, less in Whites and African Americans. Corneal power varied slightly with age, with girls showing a greater mean corneal power. Native-American children had greater corneal toricity with a markedly flatter horizontal corneal power. Anterior chambers were longer with age, and boys had deeper anterior chambers. Native-American children had the shallowest anterior chambers and Whites the deepest. Girls had higher Gullstrand and calculated lens powers than boys. Boys had longer vitreous chambers and axial lengths, and both were longer with age. Native Americans had the longest vitreous chambers and Whites the shortest. CONCLUSIONS: Most ocular components showed little clinically meaningful variation by ethnicity. The shallower anterior chambers and deeper vitreous chambers of Native-American children appeared to be offset by flatter corneas. The relatively deeper anterior chambers and shallower vitreous chambers of White children appeared to be offset by steeper corneas. Asian children had more myopic spherical equivalent refractive errors, but for a given refractive error the ocular parameters of Asian children were moderate in value compared with those of other ethnic groups. Asian children may develop longer, myopic eyes more often than other ethnic groups, but the eyes of Asian emmetropes do not appear to be innately longer.