Accuracy of a low-cost, portable, refractive error estimation device: Results of a diagnostic accuracy trial

Sanil Joseph; Balagiri Sundar; Vinitha L Rashme; Soundarya Venkatachalam; Joshua R Ehrlich; Thulasiraj Ravilla

doi:10.1371/journal.pone.0272451

Accuracy of a low-cost, portable, refractive error estimation device: Results of a diagnostic accuracy trial

PLoS One. 2022 Aug 3;17(8):e0272451. doi: 10.1371/journal.pone.0272451. eCollection 2022.

Authors

Sanil Joseph^{1

2

3}, Balagiri Sundar⁴, Vinitha L Rashme⁵, Soundarya Venkatachalam¹, Joshua R Ehrlich^{6

7}, Thulasiraj Ravilla¹

Affiliations

¹ Lions Aravind Institute of Community Ophthalmology, Madurai, India.
² Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.
³ Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia.
⁴ Department of Biostatistics Aravind Eye Hospital, Madurai, India.
⁵ Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Madurai, India.
⁶ Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, United States America.
⁷ Institute for Social Research, University of Michigan, Ann Arbor, MI, United States America.

Abstract

Purpose: To assess the accuracy of refraction measurements by ClickCheckTM compared with the standard practice of subjective refraction at a tertiary level eye hospital.

Design: Diagnostic accuracy trial.

Methods: All participants, recruited consecutively, underwent auto-refraction (AR) and subjective refraction (SR) followed by refraction measurement using ClickCheckTM (CR) by a trained research assistant. Eyeglass prescriptions generated using ClickCheckTM and the resulting visual acuity (VA) was compared to SR for accuracy. Inter-rater reliability and agreement were determined using Intra-class correlation and Bland Altman analysis respectively.

Results: The 1,079 participants enrolled had a mean (SD) age of 39.02 (17.94) years and 56% were women. Overall, 45.3% of the participants had refractive error greater than ±0.5D. The mean (SD) spherical corrections were -0.66D (1.85) and -0.89D (2.20) in SR and CR respectively. There was high level of agreement between the spherical power measured using SR and CR (ICC: 0.940 (95% CI: 0.933 to 0.947). For the assessment of cylindrical correction, there was moderate level of agreement between SR and CR (ICC: 0.493 (0.100 to 0.715). There was moderate level of agreement between the VA measurements performed by using corrections from SR and CR (ICC: 0.577 (95% CI: 0.521-0.628). The subgroup analysis based on the age categories also showed high level of agreement for spherical corrections between the two approaches (ICC: 0.900). Bland Altman analysis showed good agreement for spherical corrections between SR and CR (Mean difference: 0.224D; 95% LoA: -1.647 D to 2.096 D) without evidence of measurement bias.

Conclusions: There was a high level of agreement for spherical power measurement between CR and SR. However, improvements are needed in order to accurately assess the cylindrical power. Being a portable, low-cost and easy-to-use refraction device, ClickCheckTM can be used for first level assessment of refractive errors, thereby enhancing the efficiency of refractive services, especially in low- and-middle-income countries.

Publication types

Clinical Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Female
Humans
Male
Middle Aged
Refraction, Ocular*
Refractive Errors* / diagnosis
Reproducibility of Results
Vision Tests
Visual Acuity

Grants and funding

This study was funded by ESSILOR AMERA PTE LIMITED. The funders did not play any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. JRE was supported by an unrestricted grant from Research to Prevent Blindness to the University of Michigan Department of Ophthalmology and Visual Sciences.