Clinical Accuracy of the Nidek ARK-1 Autorefractor.

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 (J0; P = .08) and oblique cylindrical vector (J45; 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.

Ocular surface symptoms among individuals exposed to ambient levels of traffic derived air pollution - a cross-sectional study.

Background: The ocular surface is separated by a thin layer of tear film from outdoor air pollutants making individuals exposed to outdoor air pollution prone to various ocular surface disorders. The aim of this study was to determine the magnitude of ocular surface disorders symptoms among traffic police officers of Kathmandu, Nepal. Methods: Two hundred traffic police officers working at different traffic police office branches of Kathmandu, Nepal were invited to the police headquarters for eye and vision examination. Among them, 91 individuals (95% males) completed the ocular surface disease index (OSDI) questionnaire and underwent Schirmer's I tear test. Results: Symptoms of ocular surface disorders were reported by over 80% of the individuals. Approximately two fifths of the individuals (38%) reported severe symptoms.  Only 17% of the individuals' tear secretion was found to be below normal using the Schirmer's tear test.  There was no association between the OSDI score and Schirmer's tear test scores (r = 0.008, p = 0.94). A weak but significant relationship was observed between the OSDI score and job duration (r=0.21,p = 0.04). Individual exposed to outdoor air pollution for more than 10 years had higher odds of reporting ocular surface complaints as compared to those who were exposed for less than 10 years (OR = 3.94, p = 0.02). Conclusion: Ocular surface disorder symptoms are common among traffic police officers of Kathmandu, Nepal. The duration of exposure appears to significantly contribute to the increased symptoms in this vulnerable population.