To compare the refractive measurements obtained using a photorefractor (PlusoptiX S09, PlusoptiX GmbH, Germany) with those obtained using cycloplegic refraction in children.
MethodsWe 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 (≥+3.5 D), myopia (≥-3.0 D), with the rule or against the rule astigmatism (≥-1.5 D), and oblique astigmatism (≥-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.
ResultsThe 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.
ConclusionsPlusoptiX S09 is a relatively useful method for detecting RARFs, but the device tends toward myopic shift compared to cycloplegic refraction, and hyperopia is underestimated.