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

## TL;DR

This study tests a portable, affordable autorefractor in a low-resource area of Brazil to measure vision problems and compares it to traditional methods.

## Contribution

The study evaluates the performance of a low-cost autorefractor in a low-resource setting for detecting refractive errors.

## Key findings

- The QSF showed a moderate negative bias in measuring refractive errors compared to subjective clinical refractometry.
- The device demonstrated good predictability for detecting significant refractive errors in a low-resource setting.
- Cycloplegia improved the accuracy of the QSF measurements but did not eliminate the underestimation of refractive values.

## Abstract

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 (p < 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.