Objective:

Compare HOTV and tumbling E visual acuity tests in children, including their screening performance and testability.

Approach:

• Study design: Cross-sectional study of 995 children aged 3–15 years in Shanghai.
• Testing: Each child completed HOTV and tumbling E logMAR testing in randomized order, with a 30-minute rest between tests, plus cycloplegic refraction and comprehensive eye examination.

Key Findings:

• Mean uncorrected visual acuity was better with HOTV than tumbling E: 0.15 versus 0.20 logMAR.
• The difference was largest in children aged 3–4 years and remained greater than three letters in children younger than 8; it was one letter or less in older children.
• Among 183 preschool children, reduced acuity was identified in 18.6% with HOTV and 31.2% with tumbling E. HOTV had a higher true-positive rate (0.68 versus 0.44) and better specificity.
• Testability was similar: 95.1% for HOTV and 96.5% for tumbling E, a nonsignificant difference. HOTV required modestly longer instruction and testing time.
• Both tests missed some ocular conditions, particularly hyperopia and borderline refractive errors.

Interpretation:

The authors attribute the larger difference in younger children to the directional and visuospatial demands of tumbling E, rather than an inherent optical advantage of HOTV. They support HOTV as the preferred screening test for children younger than 8.

Limitations:

• Both tests were administered on the same day, creating a measurable fatigue effect despite the 30-minute rest interval.

Conclusion:

In this study, HOTV produced better acuity results and screening performance than tumbling E in younger children, while testability was comparable.

Sources:

• Article context provided