Erin Harvey - Academia.edu (original) (raw)

Papers by Erin Harvey

Research paper thumbnail of Interobserver agreement for grating acuity and letter acuity assessment in 1- to 5.5-year-olds with severe retinopathy of prematurity

Investigative Ophthalmology &amp Visual Science

PURPOSE. TO evaluate interobserver test-retest reliability of the Teller Acuity Card procedure fo... more PURPOSE. TO evaluate interobserver test-retest reliability of the Teller Acuity Card procedure for assessment of grating acuity at ages 1, 2, 3.5, 4.5, and 55 years, for HOTV letter acuity at 35 and 4.5 years, and for Early-Treatment Diabetic Retinopathy Study (ETDRS) letter acuity at 55 years in the multicenter study of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP).

Research paper thumbnail of Peripheral stimulus flicker enhances measured visual field extent in toddlers

Research paper thumbnail of Prescribing spectacles by confirmed autorefraction

ABSTRACT © 2000 Optical Society of America

Research paper thumbnail of Optical Treatment Reduces Amblyopia in Astigmatic Children Who Receive Spectacles Before Kindergarten

Ophthalmology, 2009

To examine the effect of spectacle correction of astigmatism during preschool on best-corrected r... more To examine the effect of spectacle correction of astigmatism during preschool on best-corrected recognition visual acuity (VA), grating VA, and meridional amblyopia (difference between acuity for vertical versus horizontal gratings) once the children reach kindergarten.

Research paper thumbnail of Prevalence of Astigmatism in Native American Infants and Children

Optometry and Vision Science, 2010

To describe the prevalence of high astigmatism in infants and young children who are members of a... more 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. SureSight autorefraction measurements were obtained for 1461 Tohono O'odham children aged 6 months to 8 years. 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. 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.

Research paper thumbnail of Changes in visual function following optical treatment of astigmatism-related amblyopia

Vision Research, 2008

Effects of optical correction on best-corrected grating acuity (vertical (V), horizontal (H), obl... more Effects of optical correction on best-corrected grating acuity (vertical (V), horizontal (H), oblique (O)), vernier acuity (V, H, O), contrast sensitivity (1.5, 6.0, and 18.0 cy/deg spatial frequency, V and H), and stereoacuity were evaluated prospectively in 4-to 13-year-old astigmats and a non-astigmatic age-matched control group. Measurements made at baseline (eyeglasses dispensed for astigmats), 6 weeks, and 1 year showed greater improvement in astigmatic than non-astigmatic children for all measures. Treatment effects occurred by 6 weeks, and did not differ by cohort (<8 vs. P8 years), but astigmatic children did not attain normal levels of visual function.

Research paper thumbnail of Spherical Equivalent Refractive Error in Preschool Children From a Population With a High Prevalence of Astigmatism

Optometry and Vision Science, 2007

To describe spherical equivalent (sph eq) refractive errors in preschool members of a Native Amer... more To describe spherical equivalent (sph eq) refractive errors in preschool members of a Native American tribe with a high prevalence of astigmatism. Cycloplegic autorefraction measurements were obtained for 819 three- and four-year-old Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children, with follow-up measurements in 146 after 4 to 8 years. Mean sph eq was significantly more hyperopic in the astigmatic group than in the non-astigmatic group (1.24 vs. 0.87 D). At follow-up, prevalence of hyperopic sph eq and hyperopic astigmatism had significantly decreased, and prevalence of emmetropic/myopic sph eq and myopic astigmatism had significantly increased. The decrease in mean sph eq was similar in astigmats and non-astigmats. Astigmatism did not change over time. Most preschool children in this highly astigmatic population are hyperopic, with astigmats showing higher mean hyperopic sph eq than non-astigmats. Astigmats and non-astigmats show a similar decrease in amount of hyperopic sph eq over follow-up of 4 to 8 years.

Research paper thumbnail of Anisometropia Prevalence in a Highly Astigmatic School-Aged Population

Optometry and Vision Science, 2008

To describe prevalence of anisometropia, defined in terms of both sphere and cylinder, examined c... more To describe prevalence of anisometropia, defined in terms of both sphere and cylinder, examined cross-sectionally, in school-aged members of a Native American tribe with a high prevalence of astigmatism. Cycloplegic autorefraction measurements, confirmed by retinoscopy and, when possible, by subjective refraction were obtained from 1041 Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children, 4 to 13 years of age. Astigmatism &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 diopter (D) was present in one or both eyes of 462 children (44.4%). Anisometropia &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D spherical equivalent (SE) was found in 70 children (6.7%), and anisometropia &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D cylinder was found in 156 children (15.0%). Prevalence of anisometropia did not vary significantly with age or gender. Overall prevalence of significant anisometropia was 18.1% for a difference between eyes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D SE or cylinder. Vector analysis of between-eye differences showed a prevalence of significant anisometropia of 25.3% for one type of vector notation (difference between eyes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D for M and/or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =0.50 D for J0 or J45), and 16.2% for a second type of vector notation (between-eye vector dioptric difference &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.41). Prevalence of SE anisometropia is similar to that reported for other school-aged populations. However, prevalence of astigmatic anisometropia is higher than that reported for other school-aged populations.

Research paper thumbnail of Corneal and Refractive Astigmatism in a Sample of 3- to 5-Year-Old Children with a High Prevalence of Astigmatism

Optometry and Vision Science, 1999

To examine the relation between corneal and refractive astigmatism in a sample of pre-school-age ... more To examine the relation between corneal and refractive astigmatism in a sample of pre-school-age Native American children with a high prevalence of astigmatism. Subjects were 250 Tohono O&#39;Odham children, 3 to 5 years of age. Each child had corneal astigmatism measured with the Marco Nidek KM-500 portable autokeratometer without pupil dilation, and with the Nikon Retinomax K-Plus portable autorefractor/autokeratometer without and with pupil dilation. Refractive astigmatism was measured using the Retinomax K-Plus, with cycloplegia, confirmed by retinoscopy. Corneal astigmatism exceeded refractive astigmatism, with a median vector dioptric difference of 0.88 D for the KM-500, 0.76 D for the Retinomax K-Plus without dilation, and 0.75 for the Retinomax K-Plus with dilation. The relation between corneal and refractive astigmatism was adequately described by the modification by Grosvenor et al. of Javal&#39;s rule, but not by laval&#39;s rule. The results are in agreement with data reported previously for older Native American and non-Native American populations. The modified laval&#39;s rule adequately describes the relation between corneal and refractive astigmatism in a population; however, this rule does not provide accurate prediction of refractive astigmatism in individual children or adults.

Research paper thumbnail of Amblyopia in Astigmatic Infants and Toddlers

Optometry and Vision Science, 2010

Purpose-To determine if reduced astigmatism-corrected acuity for vertical (V) and/or horizontal (... more Purpose-To determine if reduced astigmatism-corrected acuity for vertical (V) and/or horizontal (H) gratings and/or meridional amblyopia (MA) are present prior to age three years in children who have with-the-rule astigmatism.

Research paper thumbnail of Prevalence of High Astigmatism, Eyeglass Wear, and Poor Visual Acuity Among Native American Grade School Children

Optometry and Vision Science, 2006

The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and... more The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism. Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham Reservation. Noncycloplegic autorefraction was conducted on the right and left eye of each child using the Nikon Retinomax K+ autorefractor, and monocular recognition acuity was tested using ETDRS logarithm of the minimum angle of resolution (logMAR) letter charts. Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children had a high prevalence of high astigmatism (42% had &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or = 1.00 D in the right or left eye) and the axis of astigmatism was uniformly with-the-rule. However, only a small percentage of children arrived at the vision screening wearing glasses, and the prevalence of poor visual acuity (20/40 or worse in either eye) was high (35%). There was a significant relation between amount of astigmatism and uncorrected visual acuity with each additional diopter of astigmatism resulting in an additional 1 logMAR line reduction in visual acuity. Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children. The results highlight the importance of improving glasses-wearing compliance, determining barriers to receiving eye care, and initiating public education programs regarding the importance of early identification and correction of astigmatism in Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children.

Research paper thumbnail of Optical Treatment of Amblyopia in Astigmatic Children

Ophthalmology, 2007

To compare the effectiveness of eyeglass treatment of astigmatism-related amblyopia in children y... more To compare the effectiveness of eyeglass treatment of astigmatism-related amblyopia in children younger than 8 years (range, 4.75-7.99 years) versus children 8 years of age and older (range, 8.00-13.53 years) over short (6-week) and long (1-year) treatment intervals. Prospective, interventional, comparative case-control study. Four hundred forty-six nonastigmatic (right and left eye, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.75 diopters [D]) and 310 astigmatic (RE, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D) Native American (Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham) children in kindergarten or grades 1 through 6. Eyeglass correction of refractive error, prescribed for full-time wear, in astigmatic children. Amount of change in mean right-eye best-corrected letter visual acuity for treated astigmatic children versus untreated, age-matched nonastigmatic children after short (6-week) and long (1-year) treatment intervals. Astigmatic children had significantly reduced mean best-corrected visual acuity at baseline compared to nonastigmatic children. Astigmats showed significantly greater improvement in mean best-corrected visual acuity (0.08 logarithm of the minimum angle of resolution [logMAR] unit; approximately 1 line), than the nonastigmatic children (0.01 logMAR unit) over the 6-week treatment interval. No additional treatment effect was observed between 6 weeks and 1 year. Treatment effectiveness was not dependent on age group (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;8 years vs. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =8 years) and was not influenced by previous eyeglass treatment. Despite significant improvement, mean best-corrected visual acuity in astigmatic children remained significantly poorer than in nonastigmatic children after 1 year of eyeglass treatment, even when analyses were limited to results from highly compliant children. Sustained eyeglass correction results in significant improvement in best-corrected visual acuity in astigmatic children, including those previously believed to be beyond the sensitive period for successful treatment.

Research paper thumbnail of Normative Monocular Visual Acuity for Early Treatment Diabetic Retinopathy Study Charts in Emmetropic Children 5 to 12 Years of Age

Ophthalmology, 2009

Objective-To provide normative data for children tested with Early Treatment Diabetic Retinopathy... more Objective-To provide normative data for children tested with Early Treatment Diabetic Retinopathy Study (ETDRS) charts.

Research paper thumbnail of Amblyopia in astigmatic preschool children

Journal of Vision, 2002

Best-corrected acuity was measured for vertical and horizontal gratings and for recognition acuit... more Best-corrected acuity was measured for vertical and horizontal gratings and for recognition acuity optotypes (Lea Symbols) in a group of three-to five-year-old children with a high prevalence of astigmatism. Results showed meridional amblyopia (MA) among children with simple/compound myopic or mixed astigmatism, due to reduced acuity for horizontal gratings. Children with simple/ compound hyperopic astigmatism showed no MA, but did show reduced acuity for both grating orientations. Reduced best-corrected recognition acuity was shown by both myopic/mixed and hyperopic astigmats. These results suggest that optical correction of astigmatism should be provided prior to age three to five years, to prevent development of amblyopia.

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

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2009

Purpose-To evaluate the accuracy of the Welch Allyn SureSight in noncycloplegic measurements of a... more 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.

Research paper thumbnail of Prescribing Eyeglass Correction for Astigmatism in Infancy and Early Childhood: A Survey of AAPOS Members

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2005

To determine prescribing practices of pediatric ophthalmologists for astigmatism and astigmatic a... more To determine prescribing practices of pediatric ophthalmologists for astigmatism and astigmatic anisometropia in infants and young children. Methods: A survey was sent to the 700 North American AAPOS members listed in the 2004 web site directory. Results: A total of 412/700 surveys (59%) were returned. The level of astigmatism at which pediatric ophthalmologists prescribe eyeglasses for astigmatism varies considerably across the age range from birth to 3 years. The level at which 50% would prescribe glasses was Ն4.00 D from 0 to Ͻ6 months and decreased to Ն2.00 D by 2 to Ͻ3 years. Furthermore, one-fifth indicated that they would not prescribe eyeglasses for astigmatism in infants Ͻ6 months of age. Prescribing practices for astigmatic anisometropia were slightly less variable across age, with 50% of respondents indicating that they would prescribe eyeglasses for astigmatic anisometropia Ն3.00 D from 0 to Ͻ6 months, decreasing to Ն1.50 D by 2 to Ͻ3 years.

Research paper thumbnail of Associations between Anisometropia, Amblyopia, and Reduced Stereoacuity in a School-Aged Population with a High Prevalence of Astigmatism

Investigative Ophthalmology & Visual Science, 2008

To describe the relation between magnitude of anisometropia and interocular acuity difference (IA... more To describe the relation between magnitude of anisometropia and interocular acuity difference (IAD), stereoacuity (SA), and the presence of amblyopia in school-aged members of a Native American tribe with a high prevalence of astigmatism. Refractive error (cycloplegic autorefraction confirmed by retinoscopy), best corrected monocular visual acuity (VA; Early Treatment Diabetic Retinopathy Study logMAR charts), and best corrected SA (Randot Preschool Stereoacuity Test) were measured in 4- to 13-year-old Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children (N = 972). Anisometropia was calculated in clinical notation (spherical equivalent and cylinder) and in two forms of vector notation that take into account interocular differences in both axis and cylinder magnitude. Astigmatism &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 1.00 D was present in one or both eyes of 415 children (42.7%). Significant increases in IAD and presence of amblyopia (IAD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 2 logMAR lines) occurred, with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=1 D of hyperopic anisometropia and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=2 to 3 D of cylinder anisometropia. Significant decreases in SA occurred with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=0.5 D of hyperopic, myopic, or cylinder anisometropia. Results for vector notation depended on the analysis used, but also showed disruption of SA at lower values of anisometropia than were associated with increases in IAD and presence of amblyopia. Best corrected IAD and presence of amblyopia are related to amount and type of refractive error difference (hyperopic, myopic, or cylindrical) between eyes. Disruption of best corrected random dot SA occurs with smaller interocular differences than those producing an increase in IAD, suggesting that the development of SA is particularly dependent on similarity of the refractive error between eyes.

Research paper thumbnail of Accuracy of the Spot and Plusoptix photoscreeners for detection of astigmatism

Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus, 2015

To evaluate the accuracy of the Spot (V2.0.16) and Plusoptix S12 (ROC4, V6.1.4.0) photoscreeners ... more 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. 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. A total...

Research paper thumbnail of The effect of flicker rate on nasal and temporal measured visual field extent in infants

Optometry and Vision Science

To explore the effect of peripheral stimulus flicker rate on measured visual field extent (MVFE) ... more To explore the effect of peripheral stimulus flicker rate on measured visual field extent (MVFE) in young infants. Three hundred sixty infants (180 each at 3.5 and 7 months of age) were tested monocularly with a light-emitting diode static perimetry procedure using a double-arc perimeter with arms at 45 degrees , 135 degrees , 225 degrees , and 315 degrees . Each subject was tested with one of six flicker conditions: no flicker, 1 Hz, 3 Hz, 10 Hz, 20 Hz, and 40 Hz. An interpolated estimate of the location at which 50% of subjects detected the peripheral stimulus (corrected for spontaneous eye movements) and the mean location of the farthest spot seen were calculated across subjects for each perimeter arm for each flicker condition for each age group. Nasally, MVFE was larger for 7-month-old than for 3.5-month-old infants. Across both ages, infants showed larger MVFE for 10-Hz stimuli than for nonflickering stimuli, but MVFE did not differ between any other flicker conditions. Temporally, response to flicker varied with age. For 3.5-month-old infants, MVFE was smaller for the no flicker condition than for the 3-Hz, 10-Hz, and 20-Hz conditions, but there were no other differences across flicker conditions. For 7-month-old infants, MVFE was larger for 3-Hz stimuli than for the no flicker, 1-Hz, 20-Hz, and 40-Hz conditions, but there were no other differences across flicker conditions. Additional analyses showed that the effect of flicker rate on the percentage of subjects looking at a peripheral stimulus at a single eccentricity (29 degrees ) was similar to the effect of stimulus flicker across eccentricities, as reflected in MVFE. Peripheral stimulus flicker can enhance the MVFE in 3.5- and 7-month-old infants. However, the effect depends on flicker rate and is consistent with previous data indicating that 10 Hz and perhaps 3 Hz are especially effective in enhancing MVFE in older infants and young children.

Research paper thumbnail of A Screening Protocol for Preschool Children Who Are Members of a Population with a High Prevalence of Astigmatism

A two-part screening program consisting of keratometry screening for corneal astigmatism, combine... more A two-part screening program consisting of keratometry screening for corneal astigmatism, combined with screening/rescreening of visual acuity, is proposed. Data from 374 children provided referral thresholds that would detect most children with significant astigmatism, while minimizing over-referrals.

Research paper thumbnail of Interobserver agreement for grating acuity and letter acuity assessment in 1- to 5.5-year-olds with severe retinopathy of prematurity

Investigative Ophthalmology &amp Visual Science

PURPOSE. TO evaluate interobserver test-retest reliability of the Teller Acuity Card procedure fo... more PURPOSE. TO evaluate interobserver test-retest reliability of the Teller Acuity Card procedure for assessment of grating acuity at ages 1, 2, 3.5, 4.5, and 55 years, for HOTV letter acuity at 35 and 4.5 years, and for Early-Treatment Diabetic Retinopathy Study (ETDRS) letter acuity at 55 years in the multicenter study of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP).

Research paper thumbnail of Peripheral stimulus flicker enhances measured visual field extent in toddlers

Research paper thumbnail of Prescribing spectacles by confirmed autorefraction

ABSTRACT © 2000 Optical Society of America

Research paper thumbnail of Optical Treatment Reduces Amblyopia in Astigmatic Children Who Receive Spectacles Before Kindergarten

Ophthalmology, 2009

To examine the effect of spectacle correction of astigmatism during preschool on best-corrected r... more To examine the effect of spectacle correction of astigmatism during preschool on best-corrected recognition visual acuity (VA), grating VA, and meridional amblyopia (difference between acuity for vertical versus horizontal gratings) once the children reach kindergarten.

Research paper thumbnail of Prevalence of Astigmatism in Native American Infants and Children

Optometry and Vision Science, 2010

To describe the prevalence of high astigmatism in infants and young children who are members of a... more 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. SureSight autorefraction measurements were obtained for 1461 Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children aged 6 months to 8 years. The prevalence of astigmatism &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;2.00 diopters was 30% in Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children during infancy (6 months to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 year of age) and was 23 to 29% at ages 2 to 7 years. However, prevalence dipped to 14% in children 1 to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;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. As in non-Native American populations, Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;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&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children increases by age 2 to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;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.

Research paper thumbnail of Changes in visual function following optical treatment of astigmatism-related amblyopia

Vision Research, 2008

Effects of optical correction on best-corrected grating acuity (vertical (V), horizontal (H), obl... more Effects of optical correction on best-corrected grating acuity (vertical (V), horizontal (H), oblique (O)), vernier acuity (V, H, O), contrast sensitivity (1.5, 6.0, and 18.0 cy/deg spatial frequency, V and H), and stereoacuity were evaluated prospectively in 4-to 13-year-old astigmats and a non-astigmatic age-matched control group. Measurements made at baseline (eyeglasses dispensed for astigmats), 6 weeks, and 1 year showed greater improvement in astigmatic than non-astigmatic children for all measures. Treatment effects occurred by 6 weeks, and did not differ by cohort (<8 vs. P8 years), but astigmatic children did not attain normal levels of visual function.

Research paper thumbnail of Spherical Equivalent Refractive Error in Preschool Children From a Population With a High Prevalence of Astigmatism

Optometry and Vision Science, 2007

To describe spherical equivalent (sph eq) refractive errors in preschool members of a Native Amer... more To describe spherical equivalent (sph eq) refractive errors in preschool members of a Native American tribe with a high prevalence of astigmatism. Cycloplegic autorefraction measurements were obtained for 819 three- and four-year-old Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children, with follow-up measurements in 146 after 4 to 8 years. Mean sph eq was significantly more hyperopic in the astigmatic group than in the non-astigmatic group (1.24 vs. 0.87 D). At follow-up, prevalence of hyperopic sph eq and hyperopic astigmatism had significantly decreased, and prevalence of emmetropic/myopic sph eq and myopic astigmatism had significantly increased. The decrease in mean sph eq was similar in astigmats and non-astigmats. Astigmatism did not change over time. Most preschool children in this highly astigmatic population are hyperopic, with astigmats showing higher mean hyperopic sph eq than non-astigmats. Astigmats and non-astigmats show a similar decrease in amount of hyperopic sph eq over follow-up of 4 to 8 years.

Research paper thumbnail of Anisometropia Prevalence in a Highly Astigmatic School-Aged Population

Optometry and Vision Science, 2008

To describe prevalence of anisometropia, defined in terms of both sphere and cylinder, examined c... more To describe prevalence of anisometropia, defined in terms of both sphere and cylinder, examined cross-sectionally, in school-aged members of a Native American tribe with a high prevalence of astigmatism. Cycloplegic autorefraction measurements, confirmed by retinoscopy and, when possible, by subjective refraction were obtained from 1041 Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children, 4 to 13 years of age. Astigmatism &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 diopter (D) was present in one or both eyes of 462 children (44.4%). Anisometropia &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D spherical equivalent (SE) was found in 70 children (6.7%), and anisometropia &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D cylinder was found in 156 children (15.0%). Prevalence of anisometropia did not vary significantly with age or gender. Overall prevalence of significant anisometropia was 18.1% for a difference between eyes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D SE or cylinder. Vector analysis of between-eye differences showed a prevalence of significant anisometropia of 25.3% for one type of vector notation (difference between eyes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D for M and/or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =0.50 D for J0 or J45), and 16.2% for a second type of vector notation (between-eye vector dioptric difference &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.41). Prevalence of SE anisometropia is similar to that reported for other school-aged populations. However, prevalence of astigmatic anisometropia is higher than that reported for other school-aged populations.

Research paper thumbnail of Corneal and Refractive Astigmatism in a Sample of 3- to 5-Year-Old Children with a High Prevalence of Astigmatism

Optometry and Vision Science, 1999

To examine the relation between corneal and refractive astigmatism in a sample of pre-school-age ... more To examine the relation between corneal and refractive astigmatism in a sample of pre-school-age Native American children with a high prevalence of astigmatism. Subjects were 250 Tohono O&#39;Odham children, 3 to 5 years of age. Each child had corneal astigmatism measured with the Marco Nidek KM-500 portable autokeratometer without pupil dilation, and with the Nikon Retinomax K-Plus portable autorefractor/autokeratometer without and with pupil dilation. Refractive astigmatism was measured using the Retinomax K-Plus, with cycloplegia, confirmed by retinoscopy. Corneal astigmatism exceeded refractive astigmatism, with a median vector dioptric difference of 0.88 D for the KM-500, 0.76 D for the Retinomax K-Plus without dilation, and 0.75 for the Retinomax K-Plus with dilation. The relation between corneal and refractive astigmatism was adequately described by the modification by Grosvenor et al. of Javal&#39;s rule, but not by laval&#39;s rule. The results are in agreement with data reported previously for older Native American and non-Native American populations. The modified laval&#39;s rule adequately describes the relation between corneal and refractive astigmatism in a population; however, this rule does not provide accurate prediction of refractive astigmatism in individual children or adults.

Research paper thumbnail of Amblyopia in Astigmatic Infants and Toddlers

Optometry and Vision Science, 2010

Purpose-To determine if reduced astigmatism-corrected acuity for vertical (V) and/or horizontal (... more Purpose-To determine if reduced astigmatism-corrected acuity for vertical (V) and/or horizontal (H) gratings and/or meridional amblyopia (MA) are present prior to age three years in children who have with-the-rule astigmatism.

Research paper thumbnail of Prevalence of High Astigmatism, Eyeglass Wear, and Poor Visual Acuity Among Native American Grade School Children

Optometry and Vision Science, 2006

The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and... more The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism. Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham Reservation. Noncycloplegic autorefraction was conducted on the right and left eye of each child using the Nikon Retinomax K+ autorefractor, and monocular recognition acuity was tested using ETDRS logarithm of the minimum angle of resolution (logMAR) letter charts. Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children had a high prevalence of high astigmatism (42% had &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or = 1.00 D in the right or left eye) and the axis of astigmatism was uniformly with-the-rule. However, only a small percentage of children arrived at the vision screening wearing glasses, and the prevalence of poor visual acuity (20/40 or worse in either eye) was high (35%). There was a significant relation between amount of astigmatism and uncorrected visual acuity with each additional diopter of astigmatism resulting in an additional 1 logMAR line reduction in visual acuity. Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children. The results highlight the importance of improving glasses-wearing compliance, determining barriers to receiving eye care, and initiating public education programs regarding the importance of early identification and correction of astigmatism in Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children.

Research paper thumbnail of Optical Treatment of Amblyopia in Astigmatic Children

Ophthalmology, 2007

To compare the effectiveness of eyeglass treatment of astigmatism-related amblyopia in children y... more To compare the effectiveness of eyeglass treatment of astigmatism-related amblyopia in children younger than 8 years (range, 4.75-7.99 years) versus children 8 years of age and older (range, 8.00-13.53 years) over short (6-week) and long (1-year) treatment intervals. Prospective, interventional, comparative case-control study. Four hundred forty-six nonastigmatic (right and left eye, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.75 diopters [D]) and 310 astigmatic (RE, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1.00 D) Native American (Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham) children in kindergarten or grades 1 through 6. Eyeglass correction of refractive error, prescribed for full-time wear, in astigmatic children. Amount of change in mean right-eye best-corrected letter visual acuity for treated astigmatic children versus untreated, age-matched nonastigmatic children after short (6-week) and long (1-year) treatment intervals. Astigmatic children had significantly reduced mean best-corrected visual acuity at baseline compared to nonastigmatic children. Astigmats showed significantly greater improvement in mean best-corrected visual acuity (0.08 logarithm of the minimum angle of resolution [logMAR] unit; approximately 1 line), than the nonastigmatic children (0.01 logMAR unit) over the 6-week treatment interval. No additional treatment effect was observed between 6 weeks and 1 year. Treatment effectiveness was not dependent on age group (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;8 years vs. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =8 years) and was not influenced by previous eyeglass treatment. Despite significant improvement, mean best-corrected visual acuity in astigmatic children remained significantly poorer than in nonastigmatic children after 1 year of eyeglass treatment, even when analyses were limited to results from highly compliant children. Sustained eyeglass correction results in significant improvement in best-corrected visual acuity in astigmatic children, including those previously believed to be beyond the sensitive period for successful treatment.

Research paper thumbnail of Normative Monocular Visual Acuity for Early Treatment Diabetic Retinopathy Study Charts in Emmetropic Children 5 to 12 Years of Age

Ophthalmology, 2009

Objective-To provide normative data for children tested with Early Treatment Diabetic Retinopathy... more Objective-To provide normative data for children tested with Early Treatment Diabetic Retinopathy Study (ETDRS) charts.

Research paper thumbnail of Amblyopia in astigmatic preschool children

Journal of Vision, 2002

Best-corrected acuity was measured for vertical and horizontal gratings and for recognition acuit... more Best-corrected acuity was measured for vertical and horizontal gratings and for recognition acuity optotypes (Lea Symbols) in a group of three-to five-year-old children with a high prevalence of astigmatism. Results showed meridional amblyopia (MA) among children with simple/compound myopic or mixed astigmatism, due to reduced acuity for horizontal gratings. Children with simple/ compound hyperopic astigmatism showed no MA, but did show reduced acuity for both grating orientations. Reduced best-corrected recognition acuity was shown by both myopic/mixed and hyperopic astigmats. These results suggest that optical correction of astigmatism should be provided prior to age three to five years, to prevent development of amblyopia.

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

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2009

Purpose-To evaluate the accuracy of the Welch Allyn SureSight in noncycloplegic measurements of a... more 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.

Research paper thumbnail of Prescribing Eyeglass Correction for Astigmatism in Infancy and Early Childhood: A Survey of AAPOS Members

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2005

To determine prescribing practices of pediatric ophthalmologists for astigmatism and astigmatic a... more To determine prescribing practices of pediatric ophthalmologists for astigmatism and astigmatic anisometropia in infants and young children. Methods: A survey was sent to the 700 North American AAPOS members listed in the 2004 web site directory. Results: A total of 412/700 surveys (59%) were returned. The level of astigmatism at which pediatric ophthalmologists prescribe eyeglasses for astigmatism varies considerably across the age range from birth to 3 years. The level at which 50% would prescribe glasses was Ն4.00 D from 0 to Ͻ6 months and decreased to Ն2.00 D by 2 to Ͻ3 years. Furthermore, one-fifth indicated that they would not prescribe eyeglasses for astigmatism in infants Ͻ6 months of age. Prescribing practices for astigmatic anisometropia were slightly less variable across age, with 50% of respondents indicating that they would prescribe eyeglasses for astigmatic anisometropia Ն3.00 D from 0 to Ͻ6 months, decreasing to Ն1.50 D by 2 to Ͻ3 years.

Research paper thumbnail of Associations between Anisometropia, Amblyopia, and Reduced Stereoacuity in a School-Aged Population with a High Prevalence of Astigmatism

Investigative Ophthalmology & Visual Science, 2008

To describe the relation between magnitude of anisometropia and interocular acuity difference (IA... more To describe the relation between magnitude of anisometropia and interocular acuity difference (IAD), stereoacuity (SA), and the presence of amblyopia in school-aged members of a Native American tribe with a high prevalence of astigmatism. Refractive error (cycloplegic autorefraction confirmed by retinoscopy), best corrected monocular visual acuity (VA; Early Treatment Diabetic Retinopathy Study logMAR charts), and best corrected SA (Randot Preschool Stereoacuity Test) were measured in 4- to 13-year-old Tohono O&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;odham children (N = 972). Anisometropia was calculated in clinical notation (spherical equivalent and cylinder) and in two forms of vector notation that take into account interocular differences in both axis and cylinder magnitude. Astigmatism &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 1.00 D was present in one or both eyes of 415 children (42.7%). Significant increases in IAD and presence of amblyopia (IAD &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 2 logMAR lines) occurred, with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=1 D of hyperopic anisometropia and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=2 to 3 D of cylinder anisometropia. Significant decreases in SA occurred with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=0.5 D of hyperopic, myopic, or cylinder anisometropia. Results for vector notation depended on the analysis used, but also showed disruption of SA at lower values of anisometropia than were associated with increases in IAD and presence of amblyopia. Best corrected IAD and presence of amblyopia are related to amount and type of refractive error difference (hyperopic, myopic, or cylindrical) between eyes. Disruption of best corrected random dot SA occurs with smaller interocular differences than those producing an increase in IAD, suggesting that the development of SA is particularly dependent on similarity of the refractive error between eyes.

Research paper thumbnail of Accuracy of the Spot and Plusoptix photoscreeners for detection of astigmatism

Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus, 2015

To evaluate the accuracy of the Spot (V2.0.16) and Plusoptix S12 (ROC4, V6.1.4.0) photoscreeners ... more 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. 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. A total...

Research paper thumbnail of The effect of flicker rate on nasal and temporal measured visual field extent in infants

Optometry and Vision Science

To explore the effect of peripheral stimulus flicker rate on measured visual field extent (MVFE) ... more To explore the effect of peripheral stimulus flicker rate on measured visual field extent (MVFE) in young infants. Three hundred sixty infants (180 each at 3.5 and 7 months of age) were tested monocularly with a light-emitting diode static perimetry procedure using a double-arc perimeter with arms at 45 degrees , 135 degrees , 225 degrees , and 315 degrees . Each subject was tested with one of six flicker conditions: no flicker, 1 Hz, 3 Hz, 10 Hz, 20 Hz, and 40 Hz. An interpolated estimate of the location at which 50% of subjects detected the peripheral stimulus (corrected for spontaneous eye movements) and the mean location of the farthest spot seen were calculated across subjects for each perimeter arm for each flicker condition for each age group. Nasally, MVFE was larger for 7-month-old than for 3.5-month-old infants. Across both ages, infants showed larger MVFE for 10-Hz stimuli than for nonflickering stimuli, but MVFE did not differ between any other flicker conditions. Temporally, response to flicker varied with age. For 3.5-month-old infants, MVFE was smaller for the no flicker condition than for the 3-Hz, 10-Hz, and 20-Hz conditions, but there were no other differences across flicker conditions. For 7-month-old infants, MVFE was larger for 3-Hz stimuli than for the no flicker, 1-Hz, 20-Hz, and 40-Hz conditions, but there were no other differences across flicker conditions. Additional analyses showed that the effect of flicker rate on the percentage of subjects looking at a peripheral stimulus at a single eccentricity (29 degrees ) was similar to the effect of stimulus flicker across eccentricities, as reflected in MVFE. Peripheral stimulus flicker can enhance the MVFE in 3.5- and 7-month-old infants. However, the effect depends on flicker rate and is consistent with previous data indicating that 10 Hz and perhaps 3 Hz are especially effective in enhancing MVFE in older infants and young children.

Research paper thumbnail of A Screening Protocol for Preschool Children Who Are Members of a Population with a High Prevalence of Astigmatism

A two-part screening program consisting of keratometry screening for corneal astigmatism, combine... more A two-part screening program consisting of keratometry screening for corneal astigmatism, combined with screening/rescreening of visual acuity, is proposed. Data from 374 children provided referral thresholds that would detect most children with significant astigmatism, while minimizing over-referrals.