Reliability of a computerized system for strabismus screening

Abstract

AIM: To evaluate the reliability of Photo-Hirschberg screening for global strabismus performed by non-specialized personnel. METHODS: Participants at three sites were enrolled. One person at each site was trained in visual acuity measurement and use of the computerized system. Visual acuity was measured, and strabismus testing was performed using two flash photographs. All data from the three primary observers were sent to an experienced assistant researcher, who was blinded to the primary results, for re-evaluation. The primary and re-evaluation results of the Photo-Hirschberg screenings using weighted kappa for agreement were compared. RESULTS: The study included 181 participants (88 males and 93 females) and the results for primary and re-evaluation screenings were corresponded. Ten participants with contrasting results presented with unclear corneal light reflex. Sensitivity and specificity were 100% [95% confidence interval (CI): 29.0%–100%] and 99.4% (95%CI: 96.6%–100%), respectively, based on the Agresti test of the primary evaluation, considering the re-evaluated classification as true. CONCLUSION: The computerized system can be used for primary strabismus screening by non-specialized personnel, with 98.8% agreement with specialists. However, it cannot be used as a substitute for professional examination.