Reliability of objective ocular torsion assessment using fundus photography in infantile esotropia

Summary Purpose To evaluate the interobserver reproducibility of objective ocular torsion measurements in infantile esotropia using fundus photography analysis. Materials and methods This retrospective observational study was conducted in our ophthalmology department at the University Hospital in Tours from 2009 to 2015. Objective Ocular torsion was assessed using fundus photography and analysed on Adobe Photoshop software within a population of children with infantile esotropia. Two observers, an orthoptist and an ophthalmologist, carried out the evaluation separately. The interobserver agreement was calculated for quantitative measurement by the interclass correlation coefficient (ICC) and by Cohen's Kappa coefficient for qualitative assessment. Results A total of 200 eyes (100 subjects, mean age: 6.88 years) were assessed. Statistical analyses for quantitative measurements resulted in an ICC of 0.98 (95% CI, 0.97–0.99) for right eyes, 0.96 (95% CI, 0.95–0.97) for left eyes, 0.98 (CI 95%, 0.97–0.98) for pre- operative eyes and 0.96 (95% CI, 0.95–0.97) for postoperative eyes. The ICC calculated on all four hundred fundus photographs was 0.97 (95% CI, 0.97–0.98). The interobserver agreement for qualitative measurements resulted in a Kappa coefficient of 0.91 for right eyes, 0.85 for left eyes, 0.90 for preoperative eyes and 0.86 for postoperative eyes. The analysis of all four hundred eyes returned a Kappa coefficient of 0.88. Conclusions Objective ocular torsion assessment using our procedure, whether by an orthoptist or ophthalmologist, is a reliable and reproducible method for the management of infantile esotropia.