Compared performance of Spot and SW800 photoscreeners on Chinese children

Purpose To evaluate the effectiveness of Spot photoscreener and SW800 vision screener in detecting amblyopia risk factors in Chinese children between 4 and 6 years of age. Methods One hundred and thirteen children (226 eyes) underwent complete ophthalmologic examination, cycloplegic retinoscopy refraction, prism cover tests and photoscreen using both Spot (v2.1.4) and SW800 (v1.0.1.0) photoscreeners. The agreement of results obtained from photoscreener and retinoscopy was evaluated by paired t-test as well as Pearson correlation test. The sensitivity and specificity of detecting amblyopia risk factors were calculated based on the American Association of Pediatric Ophthalmology and Strabismus 2013 guidelines. The overall effectiveness of detecting amblyopia risk factors by using either photoscreener was analysed by receiver operating characteristic (ROC) curves. Results A strong linear agreement was observed between Spot and retinoscopy (p< 0.01) in aspects of spherical equivalent (SE, Pearson's r= 0.95), dioptre sphere (DS, r= 0.97), dioptre cylinder (DC, r= 0.84) and horizontal deviation (Hdev, r= 0.91), with overall -0.17 D myopic shift of SE. Significant correlation was also shown between SW800 and retinoscopy (p< 0.01) in aspects of SE (r= 0.90), DS (r= 0.93), DC (r= 0.82) and Hdev (r= 0.80), with overall -0.12 D myopic shift of SE. The overall sensitivity and specificity in detecting amblyopia risk factors were 94.0% and 80.0% for Spot and 88.8% and 81.1% for SW800. Conclusion The measurements of Spot and SW800 photoscreener showed a strong agreement with cycloplegic retinoscopy refraction and prism cover tests. The performance of both screeners in detecting individual amblyopia risk factors is satisfactory. ROC analysis indicates that the Spot and SW800 performed very similarly in detecting amblyopia risk factors.