Clinical Accuracy of the Nidek ARK-1 Autorefractor. Issue 6 (June 2019)

• Record Type: Journal Article
• Authors: Paudel, Nabin; Adhikari, Sameep; Thakur, Ajit; Shrestha, Bhairaja; Loughman, James
• Is Part Of: Optometry and vision science. Volume 96:Issue 6(2019)
• Publication Date: 2019-06
• Subjects: Optometry -- Periodicals; Physiological optics -- Periodicals; Vision disorders -- Periodicals; 617.7505
• DOI: 10.1097/OPX.0000000000001386
• Languages: English
• ISSNs: 1040-5488

Abstract

Abstract : SIGNIFICANCE: Autorefractors are commonly used by eye care practitioners worldwide as a starting point for clinical prescribing and by researchers as an instrument to study development of refractive errors and accommodation. This study demonstrates that the Nidek ARK-1 provides a reasonable and repeatable estimate of refractive error. PURPOSE: The purposes of this study were ( a ) to compare refraction measurements of the Nidek ARK-1 (2016 release) autorefractor with that of subjective refraction and retinoscopy performed by an experienced clinician and ( b ) to determine the intratest and intertest variability of autorefraction measures taken using the ARK-1 autorefractor. METHODS: Sixty-seven adult patients aged 18 to 69 years underwent retinoscopy, subjective refraction, and ARK-1 autorefraction on a same day by a single clinician. A separate subset of 14 participants was invited for the repeatability and reproducibility study. Both eyes of each participant were included in the analysis. RESULTS: A statistically significant (but not clinically significant) positive spherical difference was observed between the ARK-1 and subjective refraction ( P = .003). Spherical equivalent refractive errors were statistically similar between the ARK-1 and subjective refraction ( P = .20). A statistically and clinically significant difference was observed in the cylindrical component between the ARK and subjective refraction ( P < .01). No statistically significant difference was observed between the ARK and subjective refraction in both the horizontal ( J 0 ; P = .08) and oblique cylindrical vector ( J 45 ; P = .96). Bland-Altman analysis revealed that the 95% limits of agreement were widest between the ARK and subjective refraction in all of the refractive components (−0.60 to 0.89 diopter for spherical component, −0.80 to 0.69 diopter for spherical equivalent, and −0.98 to 0.30 diopter for cylindrical component). The intertest and intratest variability of the ARK-1 was small. CONCLUSIONS: The Nidek ARK-1 autorefractor is a useful clinical tool that provides a reasonable and repeatable estimation of refractive error in adults.