Clinical Evaluation of an Affordable Handheld Wavefront Autorefractor in an Adult Population in a Low-Resource Setting in the Amazonas

This study evaluates the ability of the QuickSee Free (QSF) portable autorefractor (PlenOptika) to detect and measure refractive error compared to subjective clinical refractometry (SCR) in a Brazilian adult population in a low-resource setting in Amazonas. A total of 100 participants aged 18-65 years underwent visual acuity screening and autorefraction with and without cycloplegia using the QSF, alongside a complete ophthalmic examination including SCR. Refractive error measurements included spherical component (SC), cylindrical component (CC), cylindrical axis (CA), spherical equivalent (SE), and vector powers (MV90 and MV135). Accuracy was assessed for hyperopia ≥ +2.00 D, myopia ≤ -0.75 D, astigmatism ≥ 1.00 DC, and anisometropia ≥ 1.00 D using receiver operating characteristic (ROC) curve analysis. The area under the curve for detecting significant refractive errors ranged from 0.538 to 0.930. The mean difference between QSF without cycloplegia and SCR was -1.08 ± 1.17 D for SC and -1.15 ± 1.15 D for SE (<i>p</i> < 0.0001), and with cycloplegia, it was -0.81 ± 1.07 D and -0.83 ± 1.02 D, respectively. The QSF exhibited a moderate negative bias for both SC and SE with and without cycloplegia, underestimating these values, but it showed good predictability for detecting refractive errors in a low-resource setting.