Parent strategies for improving compliance with eyeglass wear in young children.

SIGNIFICANCE: Results of this study provide preliminary data on parent strategies for improving compliance with eyeglass treatment in young children, an age group for which previous data are limited. Parent responses provide important insights to support parents of young children who wear eyeglasses and provide preliminary data to guide additional research. PURPOSE: The goal of this exploratory study was to learn more about parents' strategies to improve compliance with eyeglass treatment of young children. METHODS: An online survey of parents of 1-year-old to less than 5-year-old children who wear eyeglasses was conducted. Parents indicated whether they used various strategies to encourage wear and were asked to provide advice for parents of young children recently prescribed eyeglasses. Use of various strategies by age was determined. Open-ended responses regarding advice for other parents were analyzed using qualitative content analysis. RESULTS: The final sample included 104 parents who were predominantly White (81%), non-Hispanic (76%), and college graduates (68%). During the 2 weeks prior to survey completion, 74% of parents reported their child wore their eyeglasses ≥8 hours/day. Use of strategies for improving eyeglass wear varied by child age. The most frequent recommendations that parents provided for other parents were to be consistent in encouraging wear, use social modeling, provide positive reinforcement when the eyeglasses are worn, and ensure that the eyeglasses fit well and were comfortable. CONCLUSIONS: Parents provided many useful insights into their experiences. However, results may not be broadly generalizable, because of the limited diversity and high rate of compliance in the study sample. Further research with more diverse populations and research on effectiveness of various strategies to increase compliance in this age group are recommended to support eyeglass treatment compliance in young children.

Objective Assessment of Spectacle Wear in Infants and Toddlers Using a Wearable Sensor.

Purpose: To assess the feasibility of using a thermal microsensor to monitor spectacle wear in infants and toddlers, to determine the inter-method reliability of two methods of estimating spectacle wear from sensor data, and to validate sensor estimates of wear. Methods: Fourteen children, 3 to <48 months of age, and one adult were provided pediatric spectacles containing their spectacle prescription. A thermal microsensor attached to the spectacle headband recorded date, time, and ambient temperature every 15 minutes for 14 days. Parents were asked for daily spectacle wear reports, and the adult recorded wear using a smartphone app. Sensor data were dichotomized (wear/non-wear) using two methods: temperature threshold (TT) and human judgment (HJ). Kappa statistics assessed inter-method reliability (child data) and accuracy (adult data). Results: Data from two child participants were excluded (one because of corrupted sensor data and the other because of no parent log data). Sensor data were collected more reliably than parent wear reports. The TT and HJ analysis of child data yielded similar reliability. Adult sensor data scored using the HJ method provided more valid estimates of wear than the TT method (κ = 0.94 vs. 0.78). Conclusions: We have demonstrated that it is feasible to deduce periods of spectacle wear using a thermal data logger and that the sensor is tolerated by children. Translational Relevance: Results indicate that it is feasible to use a thermal microsensor to measure spectacle wear for use in clinical monitoring or for research on spectacle treatment in children under 4 years of age.

The Intersection of Behavioral Economics and the General Medicine Literature.

Judgment and decision-making influence health-related behavior and clinical decision-making and, ultimately, health. It has been estimated that more than half of health disorders derive from behavioral consequences of unhealthy choices. We considered the question of how to better understand and improve decision-making in health and medicine through a narrative review of use and examples of concepts from Behavioral Economics, a field of study that combines insights from behavioral science and economic decision-making, in the 3 highest-impact general medicine journals.

Telemedicine distance and near visual acuity tests for adults and children.

We describe a set of distance and near, adult and child, visual acuity tests for home use. The five charts are packaged in a PDF document and are also available as JPEG images that can be printed on standard letter paper or displayed on a monitor or handheld device. Adult distance visual acuity is tested using a modified ETDRS Chart R; child distance vision is tested using a similarly formatted HOTV logMAR chart. Testing distance is 5 or 10 feet, appropriate for home use. Near visual acuity is displayed in the range of J16 to J1 using random words (for adults) or in HOTV matching format (for young children). An Amsler Grid and HOTV matching card are included. The charts include a calibration circle. For those without a printer, sending a JPEG image as an email attachment initiates onscreen testing with a single click. Devices with smaller screens require an assistant to scroll through the display. The test can performed without assistance from a printed page.

A preliminary study of astigmatism and early childhood development.

PURPOSE: To determine whether uncorrected astigmatism in toddlers is associated with poorer performance on the Bayley Scales of Infant and Toddler Development, 3rd edition (BSITD-III). METHODS: Subjects were 12- to 35-month-olds who failed an instrument-based vision screening at a well-child check. A cycloplegic eye examination was conducted. Full-term children with no known medical or developmental conditions were invited to participate in a BSITD-III assessment conducted by an examiner masked to the child's eye examination results. Independent samples t tests were used to compare Cognitive, Language (Receptive and Expressive), and Motor (Fine and Gross) scores for children with moderate/high astigmatism (>2.00 D) versus children with no/low refractive error (ie, children who had a false-positive vision screening). RESULTS: The sample included 13 children in each group. The groups did not differ on sex or mean age. Children with moderate/high astigmatism had significantly poorer mean scores on the Cognitive and Language scales and the Receptive Communication Language subscale compared to children with no/low refractive error. Children with moderate/high astigmatism had poorer mean scores on the Motor scale, Fine and Gross Motor subscales, and the Expressive Communication subscale, but these differences were not statistically significant. CONCLUSIONS: The results suggest that uncorrected astigmatism in toddlers may be associated with poorer performance on cognitive and language tasks. Further studies assessing the effects of uncorrected refractive error on developmental task performance and of spectacle correction of refractive error in toddlers on developmental outcomes are needed to support the development of evidence-based spectacle prescribing guidelines.

Spectacle Wear in Toddlers: Frequency of Wear and Impact of Treatment on the Child and Family.

PURPOSE: We assessed the frequency of spectacle wear and impact of spectacle treatment in toddlers. METHODS: Children 12 to <36 months old with significant refractive error were provided spectacles. After 12 (±6) weeks, parents reported the frequency of spectacle wear and completed the Amblyopia Treatment Index (ATI, modified for spectacle treatment). Factor analysis assessed usefulness of ATI for spectacle treatment. Spectacle wear and ATI results were compared across age (1- vs. 2-year-olds) and sex. RESULTS: Participants were 91 children (60% male; mean age, 22.98 [SD 6.24] months, 41 1- and 50 2-year-olds) prescribed spectacles for astigmatism (92%), hyperopia (9%), or myopia (1%). Reported frequency of wear was low (<2 hours/day) in 41%, moderate in 23% (2 to <6 hours/day), and high (≥6 hours/day) in 36% and did not differ across age or sex. ATI factor analysis identified three subscales: adverse effects, treatment compliance, and perceived benefit. One-year-olds had poorer scores on adverse effects (P = 0.026) and treatment compliance scales (P = 0.049). Low frequency of spectacle wear was associated with poorer scores on treatment compliance (P < 0.001) and perceived benefit scales (P = 0.004). CONCLUSIONS: Frequency of spectacle wear was not related to age or sex. Younger children may have more difficulty adjusting to treatment. Parents of children with low spectacle wear reported less perceived benefit of treatment. TRANSLATIONAL RELEVANCE: Data on factors associated with frequency of spectacle wear in toddlers is valuable for parents and clinicians and may lead to methods to improve compliance and reduce the negative impact of treatment.

Interrater and Test-Retest Reliability of the Beery Visual-Motor Integration in Schoolchildren.

PURPOSE: To assess interrater and test-retest reliability of the 6th Edition Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and test-retest reliability of the VMI Visual Perception Supplemental Test (VMIp) in school-age children. METHODS: Subjects were 163 Native American third- to eighth-grade students with no significant refractive error (astigmatism <1.00 D, myopia <0.75 D, hyperopia <2.50 D, anisometropia <1.50 D) or ocular abnormalities. The VMI and VMIp were administered twice, on separate days. All VMI tests were scored by two trained scorers, and a subset of 50 tests was also scored by an experienced scorer. Scorers strictly applied objective scoring criteria. Analyses included interrater and test-retest assessments of bias, 95% limits of agreement, and intraclass correlation analysis. RESULTS: Trained scorers had no significant scoring bias compared with the experienced scorer. One of the two trained scorers tended to provide higher scores than the other (mean difference in standardized scores = 1.54). Interrater correlations were strong (0.75 to 0.88). VMI and VMIp test-retest comparisons indicated no significant bias (subjects did not tend to score better on retest). Test-retest correlations were moderate (0.54 to 0.58). The 95% limits of agreement for the VMI were -24.14 to 24.67 (scorer 1) and -26.06 to 26.58 (scorer 2), and the 95% limits of agreement for the VMIp were -27.11 to 27.34. CONCLUSIONS: The 95% limit of agreement for test-retest differences will be useful for determining if the VMI and VMIp have sufficient sensitivity for detecting change with treatment in both clinical and research settings. Further research on test-retest reliability reporting 95% limits of agreement for children across different age ranges is recommended, particularly if the test is to be used to detect changes due to intervention or treatment.

Visual Motor and Perceptual Task Performance in Astigmatic Students.

Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D) or bilateral astigmatism group (right and left eye ≥ 1.00 D) based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI) and Visual Perception (VMIp). Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88). Mean VMI score in corrected astigmats did not differ from the control group (p = 0.829). Uncorrected astigmats had lower VMI scores than the control group (p = 0.038) and corrected astigmats (p = 0.007). Mean VMIp scores for uncorrected (p = 0.209) and corrected astigmats (p = 0.124) did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p = 0.003). Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

Convergence Insufficiency, Accommodative Insufficiency, Visual Symptoms, and Astigmatism in Tohono O'odham Students.

Purpose. To determine rate of convergence insufficiency (CI) and accommodative insufficiency (AI) and assess the relation between CI, AI, visual symptoms, and astigmatism in school-age children. Methods. 3rd-8th-grade students completed the Convergence Insufficiency Symptom Survey (CISS) and binocular vision testing with correction if prescribed. Students were categorized by astigmatism magnitude (no/low: <1.00 D, moderate: 1.00 D to <3.00 D, and high: ≥3.00 D), presence/absence of clinical signs of CI and AI, and presence of symptoms. Analyses determine rate of clinical CI and AI and symptomatic CI and AI and assessed the relation between CI, AI, visual symptoms, and astigmatism. Results. In the sample of 484 students (11.67 ± 1.81 years of age), rate of symptomatic CI was 6.2% and symptomatic AI 18.2%. AI was more common in students with CI than without CI. Students with AI only (p = 0.02) and with CI and AI (p = 0.001) had higher symptom scores than students with neither CI nor AI. Moderate and high astigmats were not at increased risk for CI or AI. Conclusions. With-the-rule astigmats are not at increased risk for CI or AI. High comorbidity rates of CI and AI and higher symptoms scores with AI suggest that research is needed to determine symptomatology specific to CI.

Assessment of Grating Acuity in Infants and Toddlers Using an Electronic Acuity Card: The Dobson Card.

PURPOSE: To determine if testing binocular visual acuity in infants and toddlers using the Acuity Card Procedure (ACP) with electronic grating stimuli yields clinically useful data. METHODS: Participants were infants and toddlers ages 5 to 36.7 months referred by pediatricians due to failed automated vision screening. The ACP was used to test binocular grating acuity. Stimuli were presented on the Dobson Card. The Dobson Card consists of a handheld matte-black plexiglass frame with two flush-mounted tablet computers and is similar in size and form to commercially available printed grating acuity testing stimuli (Teller Acuity Cards II [TACII]; Stereo Optical, Inc., Chicago, IL). On each trial, one tablet displayed a square-wave grating and the other displayed a luminance-matched uniform gray patch. Stimuli were roughly equivalent to the stimuli available in the printed TACII stimuli. After acuity testing, each child received a cycloplegic eye examination. Based on cycloplegic retinoscopy, patients were categorized as having high or low refractive error per American Association for Pediatric Ophthalmology and Strabismus vision screening referral criteria. Mean acuities for high and low refractive error groups were compared using analysis of covariance, controlling for age. RESULTS: Mean visual acuity was significantly poorer in children with high refractive error than in those with low refractive error (P = .015). CONCLUSIONS: Electronic stimuli presented using the ACP can yield clinically useful measurements of grating acuity in infants and toddlers. Further research is needed to determine the optimal conditions and procedures for obtaining accurate and clinically useful automated measurements of visual acuity in infants and toddlers.

Reading Fluency in School-Aged Children with Bilateral Astigmatism.

PURPOSE: To compare oral reading fluency (ORF) in students with no/low astigmatism and moderate/high astigmatism and to assess the impact of spectacle correction on ORF in moderate and high astigmats. METHODS: Subjects were third- to eighth-grade students from a highly astigmatic population. Refractive error was determined through subjectively refined cycloplegic autorefraction. Data from students with ocular abnormalities, anisometropia, symptomatic binocular vision disorders, or refractive error that did not meet study criteria (no/low [cylinder < 1.00 both eyes, no significant myopia/hyperopia], moderate [cylinder ≥ 1.00 D both eyes, mean ≥ 1.00 D and < 3.00 D], or high astigmatism group [cylinder ≥ 1.00 D both eyes, mean ≥ 3.00 D]) were excluded. Oral reading fluency was tested with a modified version of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) Next test of ORF. No/low astigmats were tested without spectacles; astigmats were tested with and without spectacles. Mean ORF was compared in no/low astigmats and astigmats (with and without correction). Improvement in ORF with spectacles was compared between moderate and high astigmats. RESULTS: The sample included 130 no/low, 67 moderate, and 76 high astigmats. ORF was lower in uncorrected astigmats than in no/low astigmats (p = 0.011). ORF did not significantly differ in no/low astigmats and corrected astigmats (p = 0.10). ORF significantly improved with spectacle correction in high astigmats (p = 0.001; mean improvement, 6.55 words per minute) but not in moderate astigmats (p = 0.193; mean improvement, 1.87 words per minute). Effects of spectacle wear were observed in students who read smaller text stimuli (older grades). CONCLUSIONS: ORF is significantly reduced in students with bilateral astigmatism (≥1.00D) when uncorrected but not when best-corrected compared with their nonastigmatic peers. Improvement in ORF with spectacle correction is seen in high astigmats but not in moderate astigmats. These data support the recommendation for full-time spectacle wear in astigmatic students, particularly those with high astigmatism.

Accuracy of the Spot and Plusoptix photoscreeners for detection of astigmatism.

PURPOSE: To evaluate the accuracy of the Spot (V2.0.16) and Plusoptix S12 (ROC4, V6.1.4.0) photoscreeners in detecting astigmatism meeting AAPOS referral criteria in students from a population with high prevalence of astigmatism. METHODS: Students attending grades 3-8 on the Tohono O'odham reservation were examined. Screening was attempted with both the Spot and Plusoptix photoscreeners. Results were compared to cycloplegic refraction. Screening attempts providing no estimate of refractive error were considered fail/refer. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detection of refractive errors were determined using AAPOS referral criteria and receiver operating characteristic area under the curve (ROC AUC) analysis was conducted for measures of astigmatism. Agreement between screening and cycloplegic refraction measurements of astigmatism, spherical equivalent, and anisometropia were assessed using t tests and correlation analyses. RESULTS: A total of 209 students were included. Of the total, 116 (55%) met examination-positive criteria based on cycloplegic refraction, with 105 of those (90%) meeting the criterion for astigmatism. Measurements success rates were 97% for Spot and 54% for Plusoptix. Comparing the Spot and the Plusoptix, sensitivity was 96% versus 100%, specificity was 87% versus 61%, PPV was 90% versus 76%, and NPV was 94% versus 100% for detection of refractive error. Both screeners overestimated astigmatism by 1/3 D to 2/3 D. AUC for astigmatism was 0.97 for Spot and 0.83 for Plusoptix. CONCLUSIONS: In this highly astigmatic population, the Spot and the Plusoptix had similar sensitivity, but the Spot had better specificity and measurement success rates. Compared with results from study samples with lower rates of astigmatism, our results highlight the need to assess the ability of screening instruments to detect individual types of refractive errors.

Higher-order aberrations and best-corrected visual acuity in Native American children with a high prevalence of astigmatism.

PURPOSE: To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. METHODS: Subjects were 218 Tohono O'odham Native American children 5-9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,-3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. RESULTS: The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 µm was significantly greater than population norms (0.100 ± 0.044 µm). All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. CONCLUSIONS: Tohono O'odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant.

Longitudinal change and stability of refractive, keratometric, and internal astigmatism in childhood.

PURPOSE: To assess longitudinal change in refractive, keratometric, and internal astigmatism in a sample of students from a population with a high prevalence of with-the-rule (WTR) astigmatism and to determine the optical origins of changes in refractive astigmatism. METHODS: A retrospective analysis of longitudinal measurements of right eye refractive and keratometric astigmatism in Tohono O'odham Native American children was conducted. Changes in refractive and keratometric astigmatism per year were compared in a younger cohort (n = 1594, 3 to <11 years old) and an older cohort (n = 648, 11 to <19 years old). Data were analyzed in clinical notation (Cyl) and vector notation (J0, J45). RESULTS: On average, refractive astigmatism (means: 1.19 diopters [D] Cyl, +0.54 J0, +0.03 J45) resulted primarily from WTR corneal astigmatism (means: +0.85 J0, -0.02 J45) and against-the-rule (ATR) internal astigmatism (means: -0.31 J0, +0.05 J45). Mean longitudinal changes in astigmatism were statistically significant (younger cohort -0.02 D/y Cyl; older cohort +0.06 D/y Cyl). In the younger cohort, astigmatism decreased with age in low and moderate astigmats (<3.00 D) and increased with age in high astigmats (≥3.00 D). In the older cohort, astigmatism increased with age across all levels of astigmatism. Longitudinal changes in keratometric and internal astigmatism were negatively correlated in both cohorts. CONCLUSIONS: Cross-sectional data suggest the presence of a constant ATR contribution from internal astigmatism (0.60 D Cyl) that is close to the 0.50 D ATR constant reported by Javal and others. Highly astigmatic 3- to <11-year-old children and children older than age 11 years show a small (not clinically significant) increase in astigmatism with age. A negative correlation between changes in keratometric astigmatism and internal astigmatism suggests an active compensation that may contribute to the stability of astigmatism in Tohono O'odham children.

Accommodation in astigmatic children during visual task performance.

PURPOSE: To determine the accuracy and stability of accommodation in uncorrected children during visual task performance. METHODS: Subjects were second- to seventh-grade children from a highly astigmatic population. Measurements of noncycloplegic right eye spherical equivalent (Mnc) were obtained while uncorrected subjects performed three visual tasks at near (40 cm) and distance (2 m). Tasks included reading sentences with stimulus letter size near acuity threshold and an age-appropriate letter size (high task demands) and viewing a video (low task demand). Repeated measures ANOVA assessed the influence of astigmatism, task demand, and accommodative demand on accuracy (mean Mnc) and variability (mean SD of Mnc) of accommodation. RESULTS: For near and distance analyses, respectively, sample size was 321 and 247, mean age was 10.37 (SD 1.77) and 10.30 (SD 1.74) years, mean cycloplegic M was 0.48 (SD 1.10) and 0.79 diopters (D) (SD 1.00), and mean astigmatism was 0.99 (SD 1.15) and 0.75 D (SD 0.96). Poor accommodative accuracy was associated with high astigmatism, low task demand (video viewing), and high accommodative demand. The negative effect of accommodative demand on accuracy increased with increasing astigmatism, with the poorest accommodative accuracy observed in high astigmats (≥3.00 D) with high accommodative demand/high hyperopia (1.53 D and 2.05 D of underaccommodation for near and distant stimuli, respectively). Accommodative variability was greatest in high astigmats and was uniformly high across task condition. No/low and moderate astigmats showed higher variability for the video task than the reading tasks. CONCLUSIONS: Accuracy of accommodation is reduced in uncorrected children with high astigmatism and high accommodative demand/high hyperopia, but improves with increased visual task demand (reading). High astigmats showed the greatest variability in accommodation.

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.

Astigmatism and myopia in Tohono O'odham Native American children.

PURPOSE: To describe change in spherical equivalent (M) in a longitudinal sample of Tohono O'odham students ages 3 to 18 years and to test the hypothesis that astigmatism creates complex cues to emmetropization, resulting in increased change in M in the direction of increasing myopia and increased occurrence of myopia. METHODS: Subjects were 777 Tohono O'odham Native American children on whom cycloplegic right eye autorefraction was measured on at least two study encounters between ages 3 and 18 years (first encounter prior to age 5.5 years, final encounter ≥3 years later). Regression lines were fit to individual subjects' longitudinal M data to estimate rate of change in M (regression slope, D/yr). Regression was also used to predict if a subject would be myopic (≤-0.75 D M) by age 18 years. Analysis of covariance was used to assess the relation between M slope and magnitude of baseline M and astigmatism. Chi-square analyses were used to assess the relation between predicted myopia onset and magnitude of baseline M and astigmatism. RESULTS: Mean M slope was significantly more negative for hyperopes (M ≥ +2.00) than for myopes (M ≤ -0.75) or for subjects neither hyperopic nor myopic (NHM, M > -0.75 and < +2.00), but there was no significant difference between the myopic and NHM groups. Chi-square analysis indicated that final myopia status varied across level of baseline astigmatism. Subjects with high astigmatism were more likely to be predicted to have significant myopia by age 18 years. CONCLUSIONS: The association between greater shift in M towards myopia with age in subjects who were hyperopic at baseline is consistent with continued emmetropization in the school years. Results regarding predicted myopia development imply that degradation of image quality due to refractive astigmatism creates complex cues to emmetropization, resulting in increased occurrence of myopia.

Utility of an open field Shack-Hartmann aberrometer for measurement of refractive error in infants and young children.

PURPOSE: To assess the utility of an open-field Shack-Hartmann aberrometer for measurement of refractive error without cycloplegia in infants and young children. METHOD: Data included 2698 subject encounters with Native American infants and children aged 6 months to <8 years. We attempted right eye measurements without cycloplegia using the pediatric wavefront evaluator (PeWE) on all participants while they viewed near (50 cm) and distant (2 m) fixation targets. Cycloplegic autorefraction (Rmax [Nikon Retinomax K-plus2]) measurements were obtained for children aged ≥ 3 years. RESULTS: The success rates of noncycloplegic PeWE measurement for near (70%) and distant targets (56%) significantly improved with age. Significant differences in mean spherical equivalent (M) across near versus distant fixation target conditions were consistent with the difference in accommodative demand. Differences in astigmatism measurements for near versus distant target conditions were not clinically significant. Noncycloplegic PeWE and cycloplegic Rmax measurements of M and astigmatism were strongly correlated. Mean noncycloplegic PeWE M was significantly more myopic or less hyperopic and astigmatism measurements tended to be greater in magnitude compared with cycloplegic Rmax. CONCLUSIONS: The PeWE tended to overestimate myopia and underestimate hyperopia when cycloplegia was not used. The PeWE is useful for measuring accommodation and astigmatism.

Comprehensive anterior segment normal values generated by rotating Scheimpflug tomography.

PURPOSE: To identify normal values for tomographic parameters that are considered useful in screening patients for refractive surgery. SETTING: Private center, Albany, New York, USA. DESIGN: Database study. METHODS: A Pentacam HR Scheimpflug system was used to examine 1 randomly selected eye of patients to determine normal values of 21 parameters considered the most clinically applicable for surgical screening. Normality of data was evaluated using the Kolmogorov-Smirnov test. Statistical analyses were performed using the Student t test to compare means and the 2-paired sample Wilcoxon signed-rank test. Results are displayed in 95.0% and 97.5% confidence intervals (CIs). RESULTS: The study evaluated 341 adults. High-end outliers at the 97.5% CI were 46.1 diopters (D) for flat keratometry (K), 47.4 D for steep K, 3.4 D for astigmatism, 3.8 µm for anterior chamber depth, 4 µm for front apical elevation, 5 µm for front elevation at the thinnest point, and 12 µm for front elevation in the central 4.0 mm. Respective posterior elevation values were 7 µm, 13 µm, and 25 µm, with a progression index maximum of 1.53 and mean of 1.19, difference between apical and thinnest pachymetric reading of 7 µm, a maximum K of 48.2 D, and an inferior-superior ratio of 1.44 D. Low-end outliers were a maximum Ambrósio relational thickness of 335 and a mean of 425, minimum pachymetry of 479 µm, thickness at the apex of 481 µm, and central 4.0 mm corneal volume of 6.31 mm(3). CONCLUSION: Scheimpflug-derived corneal tomography identified key refractive surgery parameters that may be useful in screening refractive surgical patients.

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.