Real-world evidence of the use of Cloudscaper optotypes versus LEA symbols for virtual or digital visual acuity measurement in children aged 3 to 16 years.

Abstract

Purpose: This cross-sectional study compared best-corrected visual acuity obtained using Cloudscaper symbols, a novel optotype developed according to ETDRS specifications for children's virtual screening, with that obtained using LEA symbols.

Methods: A total of 560 children aged 3-16 yr underwent visual acuity test with both Cloudscaper symbols and LS. The test application was standardized using the EyeSpy algorithm. Additionally, 147 participants were tested with the standard Snellen E paper chart. Paired t tests were performed to assess the clinical significance of logMAR visual acuity differences.

Results: The mean logMAR visual acuity with LEA symbols was 0.12 (standard deviation [SD]=0.18; range, -0.10 to 0.80), while with Cloudscaper symbols it was 0.18 (SD=0.19; range, -0.10 to 0.80). The mean difference between Cloudscaper symbols and LEA symbols was 0.099 logMAR (approximately 0.5 optotypes; SD=0.08; range, 0.0-0.14; p<0.0001). Cloudscaper symbols slightly underestimated visual acuity compared to LEA symbols. Visual acuity measured by both methods was highly correlated (Spearman's r=0.74, p<0.0001). The mean visual acuity difference between Cloudscaper symbols and the Snellen E chart was 0.0045 (p=0.805; 95% confidence interval [95% CI]), whereas the difference between LEA symbols and Snellen E was 0.0883 (p<0.001; 95% CI).

Conclusions: Cloudscaper symbols provide a reliable tool for visual screening in children. Although they slightly underestimate visual acuity compared to LEA symbols - a finding also reported when comparing ETDRS letters with LEA symbols - Cloudscaper symbols show strong agreement with Snellen E chart measurements. This suggests that Cloudscaper symbols allow precise visual acuity assessment comparable to the gold standard.