Lynn Cyert

A randomized trial of the effect of single-vision vs. bifocal lenses on myopia progression in children with esophoria.

Background Bifocals have long been thought to reduce progression of childhood myopia. However, this hypothesis has not been definitively evaluated. Methods We conducted a randomized clinical trial to test the hypothesis that bifocals slow myopia progression in children with near-point esophoria. Eighty-two myopic children were randomized to single-vision glasses (n = 40) or to bifocals with a +1.50 D add (n = 42) and were followed for 30 months. Refraction was measured by an automated refractor after cycloplegia. The primary outcome was myopia progression defined as the difference between the spherical equivalent at baseline and at the 30-month examination, averaged over both eyes. Results Follow-up was incomplete for six children in the bifocal group and one child in the single-vision group. Among the children completing the 30 months of follow up, myopia progression (mean spherical equivalent of the two eyes) averaged 0.99 D for bifocals and 1.24 D for single vision (unadjusted, p = 0.106; adjusted for age, p = 0.046). Treatment groups differed in their cumulative distributions (Kolmogorov-Smirnov procedure, p = 0.031). Evidence for a treatment effect on growth in vitreous chamber depth was similar (p = 0.046 by K.S.). Conclusion Use of bifocals, instead of single-vision glasses, by children with near-point esophoria seemed to slow myopia progression to a slight degree.

A Survey of Vision Screening Policy of Preschool Children in the United States

A state-by-state survey regarding preschool vision screening guidelines, policies, and procedures was conducted. Currently 34 states provide vision screening guidelines and 15 states require vision screening of at least some of their preschool-aged children. The Department of Public Health administers the programs in 26 states, the Department of Education in 13. A wide range of professional and lay personnel conduct preschool vision screenings, and nurses participate in the screening process in 22 states. Visual acuity is assessed in 30 states, eye alignment in 24 states, refractive error in eight states, and color vision in 10 states. A combination of screening tests is recommended in 24 states. Currently, 45 states do not require screening of all preschool children. Thus, although laws, guidelines, and recommendations exist in most states, many preschool-age children do not have access to vision screening programs.

Seasonal Variation in Myopia Progression and Ocular Elongation

Purpose. To evaluate possible seasonal variations in myopia progression and ocular elongation in school children. Methods. Seventy-one children who were enrolled in a clinical trial of bifocals were examined every 6 months for 30 months. Three 6-month intervals (“winters”) included none of the summer vacation from school, and two intervals (“summers”) included all of the summer vacation. Myopia was evaluated, after cycloplegia with 2 drops of 1% tropicamide, by automated refractor, and changes in axial length and in vitreous chamber depth were measured by A-scan ultrasonography. Data from left and right eyes were averaged because there was no evidence of a significant eye-visit interaction. Analysis of variance with a planned contrast was used to evaluate differences between the observed rates of change over the two summers compared with expected rates assuming no seasonal effect. Results. For 37 children in single-vision lenses, myopia progression rates over the two summers averaged 0.15 D compared with 0.32 D over the three winters. For 34 children in bifocal glasses, summer rates averaged 0.07 D compared with 0.30 D for winters. Analysis of variance showed that seasonal effects on myopia progression were significant (p < 0.025) for both groups for the first summer and approached significance for the second summer. Increases in vitreous chamber depth were also slower during the summer, significantly so (p < 0.01) for both summers in the single-vision group and for the second summer only in the bifocal group. Changes in axial length were somewhat slower in the summer, but the effect of season reached statistical significance in that variable only for the second summer in the bifocal group (p = 0.031). Conclusion. Myopia progression rates were slower during the 6-month periods that included all of the summer vacation than would be expected assuming no seasonal effect. Ocular growth was also slower in the summer; but that trend, in most cases, was statistically significant only for changes in vitreous chamber depth and not for axial length.

Vision screening of preschool children: evaluating the past, looking toward the future.

Vision problems of preschool children are detectable with a comprehensive eye examination; however, it is estimated that only 14% of children below the age of 6 years receive an eye examination. Screening is advocated as a cost-effective alternative to identify children in need of further vision care. Thirty-four states recommend or require vision screening of preschool children. Although laws and guidelines exist, only 21 % of preschool children are actually screened for vision problems. There is little agreement concerning the best screening methods, and no validated, highly effective model for screening vision of preschool children. Newer screening tests have been designed specifically for preschool populations, and can be administered by lay screeners. Many have not been validated. Several are recommended by states or organizations without convincing scientific evidence of their effectiveness. This paper summarizes current laws and guidelines for preschool vision screening in the United States, reviews advantages and disadvantages of several test procedures, and provides recommendations for developing future preschool vision screening programs.

Risk Factors for Amblyopia in the Vision in Preschoolers Study

OBJECTIVE To evaluate risk factors for unilateral amblyopia and for bilateral amblyopia in the Vision in Preschoolers (VIP) study. DESIGN Multicenter, cross-sectional study. PARTICIPANTS Three- to 5-year-old Head Start preschoolers from 5 clinical centers, overrepresenting children with vision disorders. METHODS All children underwent comprehensive eye examinations, including threshold visual acuity (VA), cover testing, and cycloplegic retinoscopy, performed by VIP-certified optometrists and ophthalmologists who were experienced in providing care to children. Monocular threshold VA was tested using a single-surround HOTV letter protocol without correction, and retested with full cycloplegic correction when retest criteria were met. Unilateral amblyopia was defined as an interocular difference in best-corrected VA of 2 lines or more. Bilateral amblyopia was defined as best-corrected VA in each eye worse than 20/50 for 3-year-olds and worse than 20/40 for 4- to 5-year-olds. MAIN OUTCOME MEASURES Risk of amblyopia was summarized by the odds ratios and their 95% confidence intervals estimated from logistic regression models. RESULTS In this enriched sample of Head Start children (n = 3869), 296 children (7.7%) had unilateral amblyopia, and 144 children (3.7%) had bilateral amblyopia. Presence of strabismus (P<0.0001) and greater magnitude of significant refractive errors (myopia, hyperopia, astigmatism, and anisometropia; P<0.00001 for each) were associated independently with an increased risk of unilateral amblyopia. Presence of strabismus, hyperopia of 2.0 diopters (D) or more, astigmatism of 1.0 D or more, or anisometropia of 0.5 D or more were present in 91% of children with unilateral amblyopia. Greater magnitude of astigmatism (P<0.0001) and bilateral hyperopia (P<0.0001) were associated independently with increased risk of bilateral amblyopia. Bilateral hyperopia of 3.0 D or more or astigmatism of 1.0 D or more were present in 76% of children with bilateral amblyopia. CONCLUSIONS Strabismus and significant refractive errors were risk factors for unilateral amblyopia. Bilateral astigmatism and bilateral hyperopia were risk factors for bilateral amblyopia. Despite differences in selection of the study population, these results validated the findings from the Multi-Ethnic Pediatric Eye Disease Study and Baltimore Pediatric Eye Disease Study.

Prevalence of Vision Disorders by Racial and Ethnic Group among Children Participating in Head Start

OBJECTIVE To compare the prevalence of amblyopia, strabismus, and significant refractive error among African-American, American Indian, Asian, Hispanic, and non-Hispanic white preschoolers in the Vision In Preschoolers study. DESIGN Multicenter, cross-sectional study. PARTICIPANTS Three- to 5-year old preschoolers (n=4040) in Head Start from 5 geographically disparate areas of the United States. METHODS All children who failed the mandatory Head Start screening and a sample of those who passed were enrolled. Study-certified pediatric optometrists and ophthalmologists performed comprehensive eye examinations including monocular distance visual acuity (VA), cover testing, and cycloplegic retinoscopy. Examination results were used to classify vision disorders, including amblyopia, strabismus, significant refractive errors, and unexplained reduced VA. Sampling weights were used to calculate prevalence rates, confidence intervals, and statistical tests for differences. MAIN OUTCOME MEASURES Prevalence rates in each racial/ethnic group. RESULTS Overall, 86.5% of children invited to participate were examined, including 2072 African-American, 343 American Indian (323 from Oklahoma), 145 Asian, 796 Hispanic, and 481 non-Hispanic white children. The prevalence of any vision disorder was 21.4% and was similar across groups (P=0.40), ranging from 17.9% (American Indian) to 23.3% (Hispanic). Prevalence of amblyopia was similar among all groups (P=0.07), ranging from 3.0% (Asian) to 5.4% (non-Hispanic white). Prevalence of strabismus also was similar (P=0.12), ranging from 1.0% (Asian) to 4.6% (non-Hispanic white). Prevalence of hyperopia >3.25 diopter (D) varied (P=0.007), with the lowest rate in Asians (5.5%) and highest in non-Hispanic whites (11.9%). Prevalence of anisometropia varied (P=0.009), with the lowest rate in Asians (2.7%) and highest in Hispanics (7.1%). Myopia >2.00 D was relatively uncommon (<2.0%) in all groups with the lowest rate in American Indians (0.2%) and highest rate in Asians (1.9%). Prevalence of astigmatism >1.50 D varied (P=0.01), with the lowest rate among American Indians (4.3%) and highest among Hispanics (11.1%). CONCLUSIONS Among Head Start preschool children, the prevalence of amblyopia and strabismus was similar among 5 racial/ethnic groups. Prevalence of significant refractive errors, specifically hyperopia, astigmatism, and anisometropia, varied by group, with the highest rate of hyperopia in non-Hispanic whites, and the highest rates of astigmatism and anisometropia in Hispanics.

The effect of changing from glasses to soft contact lenses on myopia progression in adolescents

At the end of a clinical trial of bifocals as myopia treatment, subjects were allowed to select any type of optical correction they wished and were asked to return in 1 year. This report gives results of that last examination with emphasis on how progression rates differed between those remaining in their original type of glasses compared with those who switched to soft contact lenses. We found that myopia progressed at an age‐adjusted average rate of 0.74 D in 19 children who switched to soft contact lens wear compared with 0.25 D for 24 children remaining in glasses (p < 0.0001). Increased growth of the vitreous chamber appeared to account for much of this excess myopia progression, although the difference in that variable did not reach statistical significance (p = 0.101). We also noted a 0.203 D steepening in the corneal curvature in contact lens wearers compared with spectacle wearers whose corneas steepened very little (0.014 D, p = 0.007). Soft contact lens wear was also accompanied by a greater change in the near‐point phoria which moved 4.5 prism dioptres in the exo direction compared with spectacle wearers who experienced only a 1.4 prism dioptre divergent shift (p = 0.048).

Vision screening for children 36 to G72 Months: Recommended practices

Purpose This article provides recommendations for screening children aged 36 to younger than 72 months for eye and visual system disorders. The recommendations were developed by the National Expert Panel to the National Center for Children’s Vision and Eye Health, sponsored by Prevent Blindness, and funded by the Maternal and Child Health Bureau of the Health Resources and Services Administration, United States Department of Health and Human Services. The recommendations describe both best and acceptable practice standards. Targeted vision disorders for screening are primarily amblyopia, strabismus, significant refractive error, and associated risk factors. The recommended screening tests are intended for use by lay screeners, nurses, and other personnel who screen children in educational, community, public health, or primary health care settings. Characteristics of children who should be examined by an optometrist or ophthalmologist rather than undergo vision screening are also described. Results There are two current best practice vision screening methods for children aged 36 to younger than 72 months: (1) monocular visual acuity testing using single HOTV letters or LEA Symbols surrounded by crowding bars at a 5-ft (1.5 m) test distance, with the child responding by either matching or naming, or (2) instrument-based testing using the Retinomax autorefractor or the SureSight Vision Screener with the Vision in Preschoolers Study data software installed (version 2.24 or 2.25 set to minus cylinder form). Using the Plusoptix Photoscreener is acceptable practice, as is adding stereoacuity testing using the PASS (Preschool Assessment of Stereopsis with a Smile) stereotest as a supplemental procedure to visual acuity testing or autorefraction. Conclusions The National Expert Panel recommends that children aged 36 to younger than 72 months be screened annually (best practice) or at least once (accepted minimum standard) using one of the best practice approaches. Technological updates will be maintained at http://nationalcenter.preventblindness.org.

ROC Analysis of the Accuracy of Noncycloplegic Retinoscopy, Retinomax Autorefractor, and SureSight Vision Screener for Preschool Vision Screening

PURPOSE To evaluate, by receiver operating characteristic (ROC) analysis, the accuracy of three instruments of refractive error in detecting eye conditions among 3- to 5-year-old Head Start preschoolers and to evaluate differences in accuracy between instruments and screeners and by age of the child. METHODS Children participating in the Vision In Preschoolers (VIP) Study (n = 4040), had screening tests administered by pediatric eye care providers (phase I) or by both nurse and lay screeners (phase II). Noncycloplegic retinoscopy (NCR), the Retinomax Autorefractor (Nikon, Tokyo, Japan), and the SureSight Vision Screener (SureSight, Alpharetta, GA) were used in phase I, and Retinomax and SureSight were used in phase II. Pediatric eye care providers performed a standardized eye examination to identify amblyopia, strabismus, significant refractive error, and reduced visual acuity. The accuracy of the screening tests was summarized by the area under the ROC curve (AUC) and compared between instruments and screeners and by age group. RESULTS The three screening tests had a high AUC for all categories of screening personnel. The AUC for detecting any VIP-targeted condition was 0.83 for NCR, 0.83 (phase I) to 0.88 (phase II) for Retinomax, and 0.86 (phase I) to 0.87 (phase II) for SureSight. The AUC was 0.93 to 0.95 for detecting group 1 (most severe) conditions and did not differ between instruments or screeners or by age of the child. CONCLUSIONS NCR, Retinomax, and SureSight had similar and high accuracy in detecting vision disorders in preschoolers across all types of screeners and age of child, consistent with previously reported results at specificity levels of 90% and 94%.

Uncorrected Hyperopia and Preschool Early Literacy: Results of the Vision in Preschoolers-Hyperopia in Preschoolers (VIP-HIP) Study.

PURPOSE To compare early literacy of 4- and 5-year-old uncorrected hyperopic children with that of emmetropic children. DESIGN Cross-sectional. PARTICIPANTS Children attending preschool or kindergarten who had not previously worn refractive correction. METHODS Cycloplegic refraction was used to identify hyperopia (≥3.0 to ≤6.0 diopters [D] in most hyperopic meridian of at least 1 eye, astigmatism ≤1.5 D, anisometropia ≤1.0 D) or emmetropia (hyperopia ≤1.0 D; astigmatism, anisometropia, and myopia <1.0 D). Threshold visual acuity (VA) and cover testing ruled out amblyopia or strabismus. Accommodative response, binocular near VA, and near stereoacuity were measured. MAIN OUTCOME MEASURES Trained examiners administered the Test of Preschool Early Literacy (TOPEL), composed of Print Knowledge, Definitional Vocabulary, and Phonological Awareness subtests. RESULTS A total of 492 children (244 hyperopes and 248 emmetropes) participated (mean age, 58 months; mean ± standard deviation of the most hyperopic meridian, +3.78±0.81 D in hyperopes and +0.51±0.48 D in emmetropes). After adjustment for age, race/ethnicity, and parent/caregivers education, the mean difference between hyperopes and emmetropes was -4.3 (P = 0.01) for TOPEL overall, -2.4 (P = 0.007) for Print Knowledge, -1.6 (P = 0.07) for Definitional Vocabulary, and -0.3 (P = 0.39) for Phonological Awareness. Greater deficits in TOPEL scores were observed in hyperopic children with ≥4.0 D than in emmetropes (-6.8, P = 0.01 for total score; -4.0, P = 0.003 for Print Knowledge). The largest deficits in TOPEL scores were observed in hyperopic children with binocular near VA of 20/40 or worse (-8.5, P = 0.002 for total score; -4.5, P = 0.001 for Print Knowledge; -3.1, P = 0.04 for Definitional Vocabulary) or near stereoacuity of 240 seconds of arc or worse (-8.6, P < 0.001 for total score; -5.3, P < 0.001 for Print Knowledge) compared with emmetropic children. CONCLUSIONS Uncorrected hyperopia ≥4.0 D or hyperopia ≥3.0 to ≤6.0 D associated with reduced binocular near VA (20/40 or worse) or reduced near stereoacuity (240 seconds of arc or worse) in 4- and 5-year-old children enrolled in preschool or kindergarten is associated with significantly worse performance on a test of early literacy.