Factors affecting outcome of acquired comitant esotropia with restricted use of digital devices: ACEDD Study 3

Objective The objective of this study is to investigate factors associated with outcomes after 3 months of instructed usage of hand-held digital devices (DD) in patients with acquired comitant esotropia (ACE).Methods and analysis This prospective multicentre observational study included patients with ACE, aged 5-35 years, who used DD within 1 year of onset and were followed up for clinical findings and instructed use of DD. The outcomes were classified into four groups: cured, improved, unchanged and worsened. After the analysis of group differences in the clinical and DD use-related factors by univariate analysis, we used ordinal logistic regression models to identify factors associated with favourable outcomes.Results Of 156 patients (mean age (SD): 16.4 (7.4) years), 10 (6%), 58 (37%), 67 (43%) and 21 (14%) were classified into the cured, improved, unchanged, and worsened, respectively. In the univariate analysis, consultation within 3 months of onset, small-angle strabismus at distance and good stereoacuity were associated with good outcomes. Ordinal logistic regression analysis on adjusting for age with stereoacuity or successful DD-use time halving showed that small-angle strabismus at distance (OR: 1.02, 95% CI 1.00 to 1.03, p=0.023), good stereoacuity (OR: 1.31; 95% CI 1.10 to 1.56; p=0.003) and successful halving of DD-use time (OR: 0.63; 95% CI 0.43 to 0.92; p=0.016) influenced favourable outcomes.Conclusion Patients with small-angle esotropia, good stereoacuity on consultation and success in halving DD-use time had a higher chance of recovery through instructional DD usage. Further studies using objectively measurable systems are needed to ensure the accuracy of DD-use time.