Reliability and Usefulness of Refractive Measurements by PlusoptiX S09 in Children

ABSTRACT

PURPOSE: To compare the refractive measurements obtained using a photorefractor (PlusoptiX S09, PlusoptiX GmbH, Germany) with those obtained using cycloplegic refraction in children. METHODS: We assessed the refractive status of 268 eyes in 134 children. The values acquired via photorefraction with a PlusoptiX S09 device were compared with those obtained by cycloplegic retinoscopy. Hyperopia (> or =+3.5 D), myopia (> or =-3.0 D), with the rule or against the rule astigmatism (> or =-1.5 D), and oblique astigmatism (> or =-1.0 D) were set as diagnostic criteria for refractive amblyopia risk factors (RARFs). The difference in the detection of RARFs by the two methods was the main outcome measure. RESULTS: The average spherical refractive power was -0.81 +/- 1.68 D for PlusoptiX S09 versus -0.26 +/- 2.00 D for cycloplegic retinoscopy (average difference -0.54 +/- 0.61 D; p < 0.001). The average spherical equivalent was -1.20 +/- 1.62 D for PlusoptiX S09 versus -0.64 +/- 1.94 D for cycloplegic retinoscopy (average difference -0.56 +/- 0.62 D; p < 0.001). The average cylinder power was -0.79 +/- 0.93 D for PlusoptiX S09 versus -0.76 +/- 0.94 D for cycloplegic retinoscopy (average difference -0.03 +/- 0.33 D; p = 0.135). Even though cycloplegic retinoscopy is considered the gold standard, the sensitivity and specificity for detecting RARFs with the PlusoptiX S09 were 88.0% and 96.3%, respectively. CONCLUSIONS: PlusoptiX S09 is a relatively useful method for detecting RARFs, but the device tends toward myopic shift compared to cycloplegic refraction, and hyperopia is underestimated.