Comparison of measurements of refractive errors between the hand-held Retinomax and on-table autorefractors in cyclopleged and noncyclopleged children

Refractive and corneal astigmatism in Chinese 4-15 years old children: prevalence and risk factors

BACKGROUND

To investigate the prevalence and risk factors of refractive astigmatism (RA) and corneal astigmatism (CA) in preschool children and school-aged children in Shanghai, China.

METHODS

In this school-based, cross-sectional study, 4-15 years old children across three learning stages of kindergarten, primary school, and junior high school underwent noncycloplegic autorefraction and completed comprehensive questionnaires involving time spent on daily homework and outdoor activities. Data from the right eyes were analysed.

RESULTS

Overall, 7084 children (mean ± standard deviation (SD) of age: 8.08 ± 3.11 years) were included, and the prevalence rates of RA/CA ( ≤ - 1.0 D) in children were 15.8%/64% in kindergartens, 16.5%/65% in primary schools, and 32.8%/76.9% in junior high schools. The magnitude and prevalence of RA and CA all increased with age or with learning stage (all P < 0.001). The presence of RA was associated with more myopic spherical power (odds ratio (OR) 0.956, P = 0.021), junior high school (OR 1.973, P < 0.001), longer homework time on weekdays (OR 1.074, P = 0.029), and shorter outdoor activity time on weekends (odds ratio 0.929, P = 0.013).

CONCLUSION

In the wide age range of 4 to 15 years, the magnitude and prevalence of RA and CA increased with the learning stage, and these increases mainly began at the primary school stage. Factors, including longer homework time and shorter outdoor time were correlated with the presence of RA.

Comparability of the Retinomax K-plus 3 handheld autorefractometer in quick mode versus on-table autorefractometer in standard mode

INTRODUCTION

This study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in Quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation.

METHODS

It is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in Quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student's t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed.

RESULTS

It included 98 eyes of 49 subjects (age range: 3-16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia.

CONCLUSION

The Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age.

Percentile curves of refractive errors in a Spanish paediatric population

OBJECTIVE

The main objective of this study was to obtain percentile curves of refractive errors in a Spanish paediatric population aged between 3 and 12 years.

MATERIALS AND METHOD

A descriptive, observational and cross-sectional study was conducted, including children aged between 3 and 12 years who did not present with any known ocular and/or systemic diseases. The convenience sampling method was used to select the sample from three schools and one hospital in the Community of Madrid. The refractive error was obtained using a Retinomax K-plus 3 autorefractometer (RTX; Right Mfg. Co. Ltd., Tokyo, Japan). The 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles were calculated using the IBM SPSS Statistics v.24 statistical software (IBM Corporation, Armonk, NY, United States).

RESULTS

A total of 688 children with a mean age of 7.68 ± 2.17 years were analysed. In the 50th percentile curve, spherical equivalent values started to become myopic at 3 years (SE < -0.50 D) and the 75th percentile curve also turned myopic at 4 years. As a result, it was observed that the spherical equivalent value became more negative with time, starting from the ages indicated above. Therefore, the 90th percentile curve was negative at 11 years.

CONCLUSION

Percentile curves of refractive errors in a Spanish paediatric population have been presented for the first time in order to help eyecare professionals detect children with refractive errors at an early age.

Accuracy of the Hand-held Wavefront Aberrometer in Measurement of Refractive Error

Purpose

To compare refractive error measured by hand-held wavefront aberrometers with postcycloplegic autorefraction (AR) and cycloplegic refraction (CR).

Methods

The medical records of patients who received refractive measurements using the wavefront aberrometer, postcycloplegic AR, and CR between January 2014 and January 2016 were retrospectively analyzed. The mean differences, 95% confidence intervals, and limits of agreement (LOA) were calculated for the refractive vector components (M, J₀, and J₄₅).

Results

Fifty-one patients (9.0 ± 5.5 years, male 41.2%) were enrolled in this study, and only the right eye of each was included. Refractive errors ranged from −9.25 to +7.25 diopters (D) for spherical equivalent (median, 0.75 D). The M component was not significantly different among the three methods (p = 0.080). However, the J₀ vector component was significantly different (p < 0.001). After post hoc analysis, the wavefront aberrometer obtained more positive values for J₀ compared to the other methods. The J₄₅ component was not significantly different among the three methods (p = 0.143). The mean difference between the wavefront aberrometer and postcycloplegic AR was −0.115 D (LOA, −1.578 to 1.348 D) for M, 0.239 D (LOA, −0.371 to 0.850 D) for J₀, and −0.015 D (LOA, −0.768 to 0.738 D) for J₄₅. The mean difference between the wavefront aberrometer and CR was −0.220 D (LOA, −1.790 to 1.350 D) for M, 0.300 D (LOA, −0.526 to 1.127 D) for J₀, and −0.079 D (−0.662 to 0.504 D) for J₄₅.

Conclusions

The wavefront aberrometer showed good agreement with postcycloplegic AR and CR in spherical equivalents, but tended to produce slightly myopic results. The wavefront aberrometer also overestimated with-the-rule astigmatism. Therefore, we recommend that the device be used for estimations of refractive error, which may be useful for patients who have postural difficulties, live in undeveloped countries, or are bedridden.

Adequacy of the Fogging Test in the Detection of Clinically Significant Hyperopia in School-Aged Children

Purpose

To evaluate the efficacy of the "fogging test," performed with a +2 diopters (D) lens, in the exclusion of clinically significant hyperopia in school-aged children.

Methods

We studied 54 children between 5 and 11 years of age, with 10/10 best-corrected bilateral visual acuity (VA) without significant degree of correction. VA was assessed in each eye with a "bilateral" +2 D sphere over-refraction followed by cycloplegic retinoscopy. The capacity of the test to detect hyperopia of ≥+2 D and ≥+1.5 D was evaluated by examining the respective receiver operating characteristic (ROC) curves and sensitivity and specificity values for different cutoff values of VA.

Results

For the detection of hyperopia ≥+2 D, the area under the ROC curve (AUC) was 0.955 (p ≤ 0.001). The VA cutoff with best discriminative capacity was ≥5/10, with a sensitivity of 100%, specificity of 79%, positive predictive value (PPV) of 57%, and negative predictive value (NPV) of 100%. In respect of ≥+1.5 D hyperopia, the test capacity was lower (AUC = 0.832; p ≤ 0.001). The best VA cutoff was also of ≥5/10, with a PPV of 81% and a NPV of 85%.

Conclusion

The accuracy of the test was high for the evaluation of ≥+2 D hyperopia but lower for ≥+1.5 D hyperopia. For the detection of ≥+2 D hyperopia, the VA cutoff of <5/10 may permit the exclusion of clinically significant hyperopia in selected children, without the need for cycloplegia. For the same cutoff, the PPV was low, meaning that in children with ≥5/10 VA cycloplegic refraction remains obligatory.

Refractive Errors and Amblyopia in the UCLA Preschool Vision Program; First Year Results

PURPOSE

To report the outcomes of full ophthalmic examination for preschool children in LA County who failed screening with the Retinomax Autorefractor.

DESIGN

Retrospective, cross-sectional study.

METHODS

Between August 2012 and May 2013, the University of California Los Angeles (UCLA) preschool vision program screened 11 260 preschool children aged 3-5 years in Los Angeles County using the Retinomax Autorefractor only. Of those, 1007 children who failed the screening were examined by an ophthalmologist on the UCLA Mobile Eye Clinic. Data from the eye examination were recorded for all children. Amblyopia was defined as unilateral if there was ≥2 line interocular difference in the best-corrected visual acuity (BCVA) and as bilateral if BCVA was <20/50 for children <4 years old and <20/40 for children ≥4 years old.

RESULTS

Glasses were prescribed for 740 (74%) of those examined. Uncorrected visual acuity for all examined children was 0.4 ± 0.2 (logMAR mean ± SD), and BCVA was 0.2 ± 0.1. Of the 88% who underwent cycloplegia, 58% had hyperopia (spherical equivalent [SE] ≥+0.50 diopter [D]), mean of +2.50 D, and 21% had myopia (SE ≤-0.50 D), mean of -1.40 D. A total of 69% had astigmatism ≥1.50 D, mean of 1.97 D (range 0-5.75). Spherical and cylindrical anisometropia ≥1.00 D were each found in 26% of those examined. Refractive amblyopia was found in 9% of those examined, or 0.8% of the original population. Of the amblyopic subjects, 77% were unilateral.

CONCLUSIONS

Screening of preschoolers with the Retinomax led to diagnosis and early treatment of uncorrected refractive errors and amblyopia. By treating children early, amblyopia may be prevented, quality of life improved, and academic achievements enhanced.

A Comparison of Refraction Defects in Childhood Measured Using Plusoptix S09, 2WIN Photorefractometer, Benchtop Autorefractometer, and Cycloplegic Retinoscopy

PURPOSE

To compare Plusoptix (Gmbh, Nuremberg, Germany), 2WIN (Adaptica, Padua, Italy), the benchtop refractometer (Auto-Kerato-Refractometer KR-8900; Topcon Co, Tokyo, Japan), and retinoscopy with regard to the consistencies.

MATERIALS AND METHODS

In our prospective study, 200 eyes of 100 patients were included. We analyzed the demographics and characteristics of the patients, the percentage of patients from whom measurements could not be obtained, the measurements from both patients' eyes of pupil diameter, spherical, cylindrical, axis, and spherical equivalence.

RESULTS

The mean age ± SD was 7.8±4.5 years (range, 1-18 years). Pupil diameter measurements were found to be consistent (Cronbach's alpha value >0.8). The sphere and spherical equivalence measurements for both eyes were found to be consistent with each other in all apparatus (Cronbach's alpha value >0.8). However, consistency was found to be lower in cylindrical values and the Jackson cross-cylinder measurements at 0° and 45° axis were found to be inconsistent with each other (Cronbach's alpha value <0.8).

CONCLUSIONS

While consistency was observed in all methods in terms of sphere and spherical equivalence, consistency dropped in cylindrical values and no consistency was observed in axis values. It is important to take this point into consideration, especially in axis measurements.

Comparison of the Retinomax hand-held autorefractor versus table-top autorefractor and retinoscopy

AIM

To compare noncycloplegic and cycloplegic results of Retinomax measurements with findings achieved after cycloplegia using table-top autorefractor and retinoscopy.

METHODS

The study included 127 patients (mean age 96.7mo, range 21 to 221). Retinomax (Rmax) (Nikon Inc., Japan) was used to obtain noncycloplegic refraction. Under cycloplegia, refraction was measured with Rmax, table-top autorefractor (TTR) (Nikon NRK 8000, Inc., Japan) and retinoscopy. The values of sphere, spherical equivalent, cylinder and axis of cylinder were recorded for Rmax, TTR and retinoscopy in each eye. All results were analyzed statistically.

RESULTS

THE MEAN SPHERIC VALUES (SV), SPHERICAL EQUIVALENT VALUES (SEV) AND CYLINDRICAL VALUES (CV) OF THE NONCYCLOPLEGIC RMAX (SV: 0.64 D, SEV: 0.65 D and CV: 0.03 D, respectively) were found to be significantly lower than cycloplegic TTR (1.43 D, 1.38 D and 0.3 D; P=0.012, P=0.011 and P=0.04, respectively) and retinoscopy (1.34 D, 1.45 D and 0.23 D; P=0.04, P=0.002 and P=0.045, respectively). Mean cycloplegic SV, SEV, CV were not significantly different between Rmax and TTR, Rmax and retinoscopy, TTR and retinoscopy. Cycloplegic or noncycloplegic axis values were not different between any method.

CONCLUSION

Rmax may be used successfully as a screening tool but may not be accurate enough for actual spectacle prescription. Cycloplegic Rmax measurements may be able to identify refractive error in children because of approximate results to retinoscopy.

Accuracy of noncycloplegic retinoscopy, retinomax autorefractor, and SureSight vision screener for detecting significant refractive errors

PURPOSE

To evaluate, by receiver operating characteristic (ROC) analysis, the ability of noncycloplegic retinoscopy (NCR), Retinomax Autorefractor (Retinomax), and SureSight Vision Screener (SureSight) to detect significant refractive errors (RE) among preschoolers.

METHODS

Refraction results of eye care professionals using NCR, Retinomax, and SureSight (n = 2588) and of nurse and lay screeners using Retinomax and SureSight (n = 1452) were compared with masked cycloplegic retinoscopy results. Significant RE was defined as hyperopia greater than +3.25 diopters (D), myopia greater than 2.00 D, astigmatism greater than 1.50 D, and anisometropia greater than 1.00 D interocular difference in hyperopia, greater than 3.00 D interocular difference in myopia, or greater than 1.50 D interocular difference in astigmatism. The ability of each screening test to identify presence, type, and/or severity of significant RE was summarized by the area under the ROC curve (AUC) and calculated from weighted logistic regression models.

RESULTS

For detection of each type of significant RE, AUC of each test was high; AUC was better for detecting the most severe levels of RE than for all REs considered important to detect (AUC 0.97-1.00 vs. 0.92-0.93). The area under the curve of each screening test was high for myopia (AUC 0.97-0.99). Noncycloplegic retinoscopy and Retinomax performed better than SureSight for hyperopia (AUC 0.92-0.99 and 0.90-0.98 vs. 0.85-0.94, P ≤ 0.02), Retinomax performed better than NCR for astigmatism greater than 1.50 D (AUC 0.95 vs. 0.90, P = 0.01), and SureSight performed better than Retinomax for anisometropia (AUC 0.85-1.00 vs. 0.76-0.96, P ≤ 0.07). Performance was similar for nurse and lay screeners in detecting any significant RE (AUC 0.92-1.00 vs. 0.92-0.99).

CONCLUSIONS

Each test had a very high discriminatory power for detecting children with any significant RE.

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.

Uncorrected visual acuity and noncycloplegic autorefraction predict significant refractive errors in Taiwanese preschool children

PURPOSE

To investigate the accuracy of uncorrected visual acuity (UCVA), stereopsis, and noncycloplegic autorefraction (NCAR) tests performed by vision-screening technicians and to determine the best referral criteria when using these methods to screen for significant refractive errors in preschool children.

DESIGN

Retrospective, case-control, and cross-sectional study.

PARTICIPANTS

We reviewed 1000 records for a population-based preschool vision-screening program. The target conditions were defined as myopia ≤-3.0 diopters (D), hyperopia ≥ 4.5 D, astigmatism ≥ 2.0 D, and anisometropia ≥ 2.0 D.

METHODS

Receiver operating characteristic (ROC) curve was used to calculate optimal referral cutoff values. The examination results obtained by the vision-screening technicians were compared with those obtained by a pediatric ophthalmologist, which were considered the gold standard.

MAIN OUTCOME MEASURES

The efficacies (sensitivity, specificity, positive predictive value, and negative predictive value) of different tests were evaluated.

RESULTS

In 7.0% (95% confidence interval [CI], 5.3-8.7) of the children, at least 1 eye showed 1 of the target conditions. If only the right eyes were considered, the prevalence of target conditions was 4.2% (95% CI, 2.9-5.5). The ROC curve analysis indicated that the NCAR cylinder test (cutoff value ≥ 0.875 D) was the best test for screening target conditions. With regard to age groups, UCVA ≤ 0.75 (Snellen equivalent) and ≤ 0.85 were the best referral criteria for ages ≤ 4 years and ≥ 5 years, respectively. Combining the UCVA test with the NCAR test (the child was referred after failing both tests) increased specificity without significantly decreasing sensitivity.

CONCLUSIONS

The UCVA and NCAR tests performed by vision-screening technicians are adequately sensitive and specific for preschool vision screening. The ROC curve analysis was used for determining the appropriate screening criteria for these tests, and combining the tests increased their accuracy. The screening criteria should be age dependent. When analyzing the test accuracy in ophthalmic problems, if the disease of interest does not symmetrically (in terms of disease severity and prevalence) involve both eyes, the prevalence based on only 1 eye should be interpreted with caution.

Validity of noncycloplegic refraction in the assessment of refractive errors: the Tehran Eye Study

PURPOSE

To determine the sensitivity and specificity of noncycloplegic autorefraction for determining refractive status compared to cycloplegic autorefraction.

METHODS

The target population was noninstitutionalized citizens of all ages, residing in Tehran in 2002, selected through stratified cluster sampling. From 6497 eligible residents, 70.3% participated in the study, from August to November 2002. Here, we report data on 3501 people over the age of 5 years who had autorefraction with and without cycloplegia (two drops of cyclopentolate 1.0% 5 min apart, with autorefraction 25 min after the second drop).

RESULTS

Overall, the sensitivity of noncycloplegic autorefraction for myopia was 99%, but the specificity was only 80.4%. In contrast, the sensitivity for hyperopia was only 47.9%, but the specificity was 99.4%. At all ages, noncycloplegic autorefraction overestimated myopia and underestimated hyperopia. Overestimation of myopia was highest in the 21-30 and 31-40 year groups. Underestimation of hyperopia was high up to the age of 50 (20-40%), but decreased with age, to about 8% after the age of 50, down to almost 0% after 70. The difference in mean spherical equivalent with and without cycloplegia fell from 0.71 dioptres (D) in the 5-10 age group to 0.14D in those over 70.

CONCLUSION

Use of noncycloplegic autorefraction in epidemiological studies leads to considerable errors relative to cycloplegic measurements, except in those over 50-60. The difference between cycloplegic and noncycloplegic measurements varies with age and cycloplegic refractive category, and there is considerable individual variation, ruling out adjusting noncycloplegic measurements to obtain accurate cycloplegic refractions.

Used glasses versus ready-made spectacles for the treatment of refractive error

BACKGROUND AND OBJECTIVE

To compare visual outcomes for used glasses versus ready-made spectacles in the treatment of refractive error.

PATIENTS AND METHODS

In this prospective, comparative case series, undilated refractive error screening examinations were conducted over a 5-week period. Patients with bilateral refractive error were treated with used glasses and ready-made spectacles powered to match their prescriptions. Snellen visual acuity was measured with no correction, best (manifest) correction, unrefined autorefraction, used glasses, and ready-made spectacles. Main outcome measurements were the mean visual improvement from uncorrected acuity and median final visual acuity after treatment with used and ready-made spectacles.

RESULTS

One hundred forty-one patients ages 18 and older with bilateral refractive error were examined. Uncorrected visual acuity in each eye improved an average of 4.5 lines with best correction, 4.0 lines with used glasses, and 3.5 lines with ready-made spectacles, with used glasses demonstrating a statistically significant advantage over ready-made spectacles (P < .001). The median visual acuity in the better eye improved from 20/60 uncorrected to 20/25 with all types of glasses. In patients with less than 1 diopter of anisometropia and greater than 1 diopter of astigmatism in each eye (49%), the ready-made spectacles performed equally as well as the used glasses (P = .95), improving vision an average of 3.9 lines for a median final visual acuity of 20/25 in the better eye.

CONCLUSION

Although both were effective, used glasses are better than ready-made spectacles for improving vision loss due to refractive error.

Treating uncorrected refractive error in adults in the developing world with autorefractors and ready-made spectacles

BACKGROUND

To evaluate a method for treating uncorrected refractive error in adults in the developing world.

DESIGN

Prospective, cross-sectional study in outpatient community health centres.

PARTICIPANTS

Eight hundred and forty subjects aged 18 and older from rural villages in Haiti and Belize.

METHODS

Undilated refractive error screening exams were conducted over a 5-day period in rural Haiti and Belize using portable autorefractors. Isometropic, spherical, ready-made spectacles were provided to patients with bilateral refractive error, astigmatism ≤ 1 dioptre in each eye and visual acuity worse than 6/9 in each eye. Visual acuity was measured with and without corrective spectacles.

MAIN OUTCOME MEASURES

  The mean visual improvement and median final visual acuity after treatment with ready-made glasses.

RESULTS

Eight hundred and forty patients aged 18 and older were screened with autorefractors. One hundred and eighty-nine subjects (22.5%) were found to have visually significant bilateral refractive error. Fifty-eight per cent (110/189) of these patients met criteria for treatment with ready-made spectacles. Visual acuity improved an average of 4.2 lines in the better eye and 4.1 lines in the worse eye with corrective glasses. The median visual acuity in the better eye was 6/6 after treatment.

CONCLUSION

Autorefractors and ready-made spectacles allow for effective treatment of uncorrected refractive error in adults in the developing world.

Clinical evaluation of the intraoperative refraction technique for intraocular lens power calculation

OBJECTIVE

To evaluate clinically the intraoperative refraction technique for intraocular lens (IOL) power calculation using 2 existing formulas proposed by Ianchulev and Leccisotti and to derive alternative formulas for this technique.

DESIGN

Comparative case series.

PARTICIPANTS

One hundred eighty-two eyes from 182 patients with cataract.

METHODS

Recruited patients were separated into a normal cornea group and a special group that included eyes with surgically altered corneas. Phacoemulsification was carried out for all cases. Intraoperative aphakic autorefraction using a portable autorefractor was performed. An IOL with power calculated before surgery then was implanted. In each eye, postoperative refraction was obtained. The IOL power that would have achieved emmetropia was calculated retrospectively. Aphakic autorefraction readings obtained during surgery were used to calculate the aphakic spherical equivalent (SE). The 2 formulas incorporating aphakic SE were applied to calculate the target IOL power. Comparison then was made to determine the accuracy of the formulas.

MAIN OUTCOME MEASURES

A difference (referred to as IOL difference) was calculated by subtracting the adjusted emmetropic IOL power determined by postoperative refraction from the emmetropic IOL power calculated by the 2 formulas using intraoperative aphakic SE.

RESULTS

One hundred forty-four patients were in the normal cornea group and 18 were in the special group. In the normal group, the Ianchulev formula showed a relatively accurate prediction for IOL power to achieve emmetropia over almost the full range of axial length except in extremely long eyes. The Leccisotti formula tended to overestimate IOL power and worked particularly poorly in short eyes. It worked best in long eyes. In the special group, neither of the 2 formulas was able to show superiority universally. Using data from the normal group, alternative formulas for IOL power calculation were derived. These new formulas then were validated on the special group that showed good estimation.

CONCLUSIONS

The Ianchulev formula could be applied to most eyes, with the exception of those in highly myopic subjects. The Leccisotti formula showed good performance in myopic patients. For eyes falling into the special group, an alternative formula, correction factor, or both, may be required. The new formulas reported herein may be an option.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Testability of vision and refraction in preschoolers: the strabismus, amblyopia, and refractive error study in singaporean children

PURPOSE

To determine the testability of several vision and refraction tests in preschool-aged children.

DESIGN

Population-based study of Chinese preschool-aged children in Singapore.

METHODS

One thousand five hundred and forty-two Singaporean Chinese children aged 6 to 72 months were recruited through door-to-door screening of government-subsidized apartments in Singapore. Trained eye professionals administered all tests, including monocular logarithm of the minimum angle of resolution visual acuity with the Sheridan Gardiner chart, monocular Ishihara color testing (Richmond Products Inc, Albuquerque, New Mexico, USA), biometric measurements using IOLMaster (Carl Zeiss, Jena, Germany), and Randot stereoacuity (Stereo Optical Co, Chicago, Illinois, USA) for children 30 to younger than 72 months. Cycloplegic refraction and keratometry measurements also were determined using a table-mounted autorefractor (Canon Autorefractor RK-F1; Canon, Tokyo, Japan) in children 24 to younger than 72 months.

RESULTS

Testabilities were 84.8% for visual acuity (40.7% for age 30 to < 36 months, 70.8% for age 36 to < 42 months, 86.7% for age 42 to < 48 months, 94.8 for age 48 to < 54 months, 98.6 for age 54 to < 66 months, and 98.7% for age 66 to < 72 months), 81.1% for the Ishihara color test, 82.2% for Randot stereoacuity, 62.2% for table mounted autorefraction, and 91.7% for IOLMaster. All testabilities significantly increased with age (P < .0001). Girls had higher testability rates than boys for the autorefraction and Randot stereoacuity tests (P = .036 and .008, respectively).

CONCLUSIONS

The vision and refraction tests were testable in a high proportion of preschool-aged Chinese Singaporeans. Preschool children in older age groups are likely to complete these tests successfully, with important implications for determining age limits for screening in the community and clinic.

Anisometropia prevalence in a highly astigmatic school-aged population

PURPOSE

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.

METHODS

Cycloplegic autorefraction measurements, confirmed by retinoscopy and, when possible, by subjective refraction were obtained from 1041 Tohono O'odham children, 4 to 13 years of age.

RESULTS

Astigmatism > or =1.00 diopter (D) was present in one or both eyes of 462 children (44.4%). Anisometropia > or =1.00 D spherical equivalent (SE) was found in 70 children (6.7%), and anisometropia > 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 > 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 > or =1.00 D for M and/or > or =0.50 D for J0 or J45), and 16.2% for a second type of vector notation (between-eye vector dioptric difference > or =1.41).

CONCLUSIONS

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.

Impact of confidence number on the screening accuracy of the retinomax autorefractor

PURPOSE

To assess the impact of Retinomax reading confidence number on screening accuracy and to determine whether repeated testing to achieve a higher confidence number improves screening accuracy in preschool children.

METHODS

Lay and nurse screeners trained in the use of the Retinomax Autorefractor screened 1452 children enrolled in the Vision in Preschoolers (VIP) Phase II Study. All children also received a comprehensive eye examination. Using statistical comparison of correlated proportions, we compared sensitivity and specificity for detecting any VIP-targeted condition and conditions grouped by severity and by type (amblyopia, strabismus, significant refractive error, and unexplained decreased visual acuity) among three groups of children who had confidence numbers below, at or above the manufacturer's suggested confidence number of 8. The reading with the highest confidence number for each eye was used in the analysis. Each child's confidence number group was defined based on the lower confidence number of the pair of readings for the two eyes. Among the 771 (53.1%) children who had repeated testing either by lay or nurse screeners because of a low confidence number (<8) for one or both eyes in the initial testing, the same analyses were also conducted to compare results between the initial reading with confidence number<8 and repeated test reading with the highest confidence number in the same child. These analyses were based on the failure criteria associated with 90% specificity for detecting any VIP condition in VIP Phase II. We also examined the association between ocular conditions and confidence number. Hochberg procedure was used to adjust the p value for multiple comparisons.

RESULTS

A lower confidence number category was associated with higher sensitivity (0.78, 0.65, and 0.61 for<8, 8, >8, respectively, p=0.04) but much lower specificity (0.64, 0.89, and 0.93, p<0.0001) of detecting any VIP-targeted condition. Through repeated testing, 87% of readings that initially had a confidence number below 8 reached 8 or above, and the increased confidence number that resulted from repeated testing was associated with significantly higher specificity (0.81 vs. 0.86, p=0.002) and a nonsignificant change (by -0.04 to 0.03) in sensitivities. Children with any VIP-targeted condition, significant refractive error, hyperopia, astigmatism, or myopia were more likely to have a low confidence number.

CONCLUSIONS

A higher confidence number obtained during Retinomax Autorefractor screening is associated with better screening accuracy. Repeated testing to reach the manufacturer's recommended minimum value is worthwhile in preschool vision screening with the Retinomax. Failure to achieve manufacturer's recommended minimum value through repeated testing should be a factor considered in referring children for a comprehensive eye examination.

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

PURPOSE

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.

METHODS

Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O'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.

RESULTS

Tohono O'odham children had a high prevalence of high astigmatism (42% had > 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.

CONCLUSIONS

Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O'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'odham children.

Comparisons of the Handheld Autorefractor, Table-Mounted Autorefractor, and Subjective Refraction in Singapore Adults

PURPOSE

The purpose of this article was to compare the Retinomax with the table-mounted autorefractor and subjective refraction in Singapore adults.

METHODS

Adults (n = 100) attending a tertiary eye hospital clinic were examined by an optometrist. First, subjective refraction testing was performed using a trial lens set, followed by handheld autorefractor tests using the Nikon Retinomax and the table-mounted autorefractor (Topcon RM8000B). Spherical equivalent and vector components of astigmatism were analyzed: J0 (Cartesian astigmatism) and J45 (oblique astigmatism).

RESULTS

The Retinomax autorefractor readings (mean = -4.69 D) were more minus compared with the table-mounted autorefractor (mean = -4.05 D) and subjective refraction (mean = -3.90 D). There were significant differences in J0 and J45 for comparisons between subjective refraction and Retinomax autorefraction, and table-mounted autorefraction and Retinomax autorefraction.

CONCLUSION

The Retinomax autorefractor measures were more minus compared with the table-mounted autorefractor and subjective refraction. The Retinomax autorefractor is not recommended for research purposes, unless in remote inaccessible areas where a portable instrument is necessary and cycloplegia is not possible.