COMPARISON OF SMARTPHONE-BASED AND AUTOMATED REFRACTION WITH SUBJECTIVE REFRACTION FOR SCREENING OF REFRACTIVE ERRORS

ABSTRACT

Purpose

To compare Netra smartphone-based and automated refraction with subjective refraction for screening of refractive errors.

Methods

Cross-sectional study at the University of Malaya Medical Centre, Kuala Lumpur. Subjects underwent subjective refraction, then automated refraction, and finally Netra smartphone-based refraction. All results were converted to power vectors (M, J0 and J45) and were analysed using repeated-measures ANOVA and Bland-Altman plots. Sensitivity and specificity were determined. The best cut-off points were determined from ROC curve analysis. P < .05 was considered statistically significant.

Results

Data from the right eyes of 204 subjects were analysed. Mean age was 36.6 ± 15.7 years (range 16–78 years). Spherical equivalent [mean (95% CI)] from Netra and automated refraction were similar, and both more myopic than subjective refraction; −2.87 (−3.23 to −2.51), −2.85 (−3.21 to −2.49) and −2.46 (−2.83 to −2.10) respectively (p < .001). Differences in J0 and J45 between Netra and subjective refraction were not statistically significant (0.10 vs 0.11 and 0.01 vs −0.02 respectively, both p > .05), but those between automated and subjective refraction were (0.06 vs 0.11 and 0.07 vs −0.02, p = .004 and p < .001 respectively). Bland Altman plots showed the 95% limits of agreement with Netra refraction were wider than with automated refraction (−2.21D to 1.42D vs. −1.90D to 1.16D respectively).

Conclusion

Netra smartphone-based refraction gives similar readings to automated refraction, and both show myopic overestimation when compared to subjective refraction. However, due to non-insignificant practical usage issues, its use as a screening tool for refractive errors is limited.

KEYWORDS:

• Netra
• smartphone-based
• automated refraction
• subjective refraction
• screening

Acknowledgments

The authors would like to thank the optometrists and research staff at the University of Malaya, Kuala Lumpur for their participation and assistance in the data collection for this project. The lecturers and staff of University of Malaya were also instrumental to the success of this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Declaration

This work has not been published anywhere previously and is not being considered for any other publication.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.