The handy eye chart: a new visual acuity test for use in children

The dynamic optotype (Dyop): a novel visual acuity test for use in children

PURPOSE

To evaluate the "dynamic optotype" (Dyop), a simple visual acuity test based on a dynamic target that requires minimal knowledge of symbols and letters.

METHODS

A total of 160 consecutive, systemically healthy children, 4-17 years of age were prospectively recruited from the Pediatric Ophthalmology Unit of Meir Medical Center. Children were tested with the Dyop visual acuity test and the Early Treatment Diabetic Retinopathy Study (ETDRS) Lea numbers chart. The results of both tests were compared. The eye with the poorest acuity was tested with the new Dyop eye chart and the Lea numbers chart. The order of the testing was reversed between children. The logMAR visual acuity scores for each eye chart were compared.

RESULTS

We found a strong linear correlation (r = 0.88) between visual acuity measures. The mean difference in visual acuity was -0.01 (95% CI, -0.02 to 0.01). The 95% limits of agreement were ±1.2 lines. The logMAR equivalent mean difference was about less than 1 letter. The Dyop test underestimated visual acuity relative to the Lea numbers chart.

CONCLUSIONS

The results of this study support the Dyop eye chart as a valid measure of visual acuity in children 4-17 years of age, with visual acuity ranging from 20/16 to 20/200.

Recognition acuity in children measured using The Auckland Optotypes

PURPOSE

Sloan letters displayed by the Electronic Visual Acuity (EVA) system are the gold standard for recognition acuity measurement in research settings. However, letters are not always appropriate for children. The Auckland Optotypes (TAO) are a new, open-access set of 10 pictograms available in regular and vanishing formats. We sought to assess feasibility of using both formats of TAO for measuring visual acuity (VA) in children using a Bayesian adaptive staircase, in a community setting.

METHODS

We tested 121 children (5-12 years old) with both formats of TAO, a handheld flipchart vision screener (Parr vision test), as well as the gold standard EVA. We measured feasibility of the three comparison tests in three ways. First, using limits of agreement (LoA) with EVA, second, calculating area under the receiver operating characteristic curve (AUC), and finally, investigating trial-by-trial responses.

RESULTS

Agreement between tests was within test-retest reliability of EVA measures (LoA_{TAO regular}  = ±0.14, LoA_{TAO vanishing}  = ±0.15, LoA_{P arr}  = ±0.16 logMAR). TAO tests were highly effective at identifying children with vision impairment (AUC_{TAO regular}  = 0.96, AUC_{TAO vanishing}  = 0.95), whereas Parr was less effective (AUC_{P arr}  = 0.82). In 5-6 year old children there was an enhanced advantage of TAO (AUC_{TAO regular}  = 0.97, AUC_{TAO vanishing}  = 0.98) over Parr (AUC_{P arr}  = 0.75). Although each child completed 16 trials, approximately 10 trials were sufficient to achieve excellent LoA, and six trials sufficient for accurate screening.

CONCLUSION

Threshold VA assessment and vision screening are feasible using both vanishing and regular formats of TAO.

Comparing distance visual acuity measurement with a novel eye chart and the Landolt C chart in a population of children aged 6-18 years

PURPOSE

The Handy Eye Chart™ is designed to assist in evaluating the visual acuity of patients with non-standard communication styles. The Handy Eye Chart™ has been previously validated against the early treatment diabetic retinopathy study (ETDRS) chart. The aim of this research is to compare visual acuity outcomes with The Handy Eye Chart™ against the international gold standard, the Landolt C chart, in a population of children.

METHODS

Sixty participants between the ages of 6 and 18 were recruited at the Pediatric Section of the Department of Ophthalmology at the Emory Eye Center. Visual acuity was evaluated using The Handy Eye Chart™ and the Landolt C Chart, altering the order of administration between charts. The visual acuity data were compared using t test, linear regression, and Bland-Altman analysis.

RESULTS

The mean difference in visual acuity was 0.02 logMAR (CI 0.009-0.04, p = 0.002). The correlation coefficient was 0.98. The Bland-Altman analysis shows the 95% limits of agreement between the charts to be -0.14 to 0.09 logMAR.

CONCLUSIONS

The Handy Eye Chart™ is a valid measure of visual acuity when compared with the international gold standard, the Landolt C Chart.

Comparison of the Handy Eye Chart and the Lea Symbols Chart in a population of deaf children aged 7-18 years

PURPOSE

To compare the results of visual acuity testing in a population of deaf children using the Handy Eye Chart versus the Lea Symbols Chart and to compare testability and preference between charts.

METHODS

A total of 24 participants were recruited at the Atlanta Area School for the Deaf. Visual Acuity was evaluated using the Handy Eye Chart and the Lea Symbols Chart. Patient preference and duration of testing were measured.

RESULTS

The mean difference between the visual acuity as measured by each chart was -0.02 logMAR (95% CI, -0.06 to 0.03). Testing with the Handy Eye Chart was an average of 13.79 seconds faster than testing with the Lea Symbols Chart (95% CI, 1.1-26.47; P = 0.03). Of the 24 participants, 17 (71%) preferred the Handy Eye Chart (95% CI: 49%-87%; P = 0.07).

CONCLUSIONS

The Handy Eye Chart is a fast, valid, and useful tool for measuring visual acuity in deaf children age 7-18 years. Additional research is needed to evaluate the utility of the Handy Eye Chart in younger children and deaf adults.

The Handy Eye Check: a mobile medical application to test visual acuity in children

PURPOSE

To compare visual acuity results obtained with the Handy Eye Chart to results obtained using the Handy Eye Check, a mobile medical application that electronically presents isolated Handy Eye Chart optotypes according the Amblyopia Treatment Study (ATS) protocol.

METHODS

Consecutive patients 6-18 years of age presenting for eye examinations between May 30, 2012, and June 26, 2012, were invited to participate. Monocular visual acuity testing was performed on the subject's poorer-seeing eye using both the Handy Eye Check and the Handy Eye Chart under the same conditions. Visual acuity was first tested using the mobile application, then using the chart, followed by repeated application testing. Patients were excluded if they were unable to undergo the required visual acuity testing or if visual acuity in the worse-seeing eye was less than 20/200 (for validity testing, but not reliability testing).

RESULTS

There was a strong linear correlation (r = 0.92) and a mean difference in acuity of -0.005 logMAR, or less than one letter (95% CI, -0.03 to 0.02), between the two tests. The 95% limits of agreement were ± 2 lines. Test-retest reliability was high, with 81% of retest scores within 0.1 logMAR (5 letters) and 100% within 0.2 logMAR (10 letters), an intraclass correlation coefficient of 0.93, and a standard error of measurement of 0.08.

CONCLUSIONS

The Handy Eye Check mobile application compares similarly to the Handy Eye Chart as a valid and reliable test of visual acuity in children age 6-18 years.