Abstract

Purpose: The evaluation of visual acuity (VA) and refraction in the Northern Finland Birth Cohort Eye study was performed using the Nidek AR-360A autorefractometer. The accuracy of the method for this population-based screening study was assessed.

Methods: Measurements of the refractive error were obtained from the right eyes of 1238 subjects (mean age 47), first objectively with the AR-360A and then subjectively by an optometrist. Agreement with the subjective refraction was calculated for sphere, cylinder, mean spherical equivalent (MSE), cylindrical vectors J₄₅ and J₀ and presbyopic correction (add). Visual acuity (VA) was measured using an ETDRS chart and the autorefractometer.

Results: The refractive error measured with the AR-360A was higher than the subjective refraction performed by the optometrist for sphere (0.007 D ± 0.24 D p = 0.30) and also for cylinder (−0.16 D ± 0.20 D p < 0.0005). The bias between the measurements of MSE, J₄₅ and J₀ was low: −0.07 D ± 0.22 D (p = 0.002), 0.01 D ± 0.43 D (p = 0.25) and −0.01 D ± 0.42 D (p = 0.43), respectively. The amount of add measured by the autorefractometer was higher than the subjective 0.35 D ± 0.29 D (p < 0.0005). There was a statistically significant correlation between VA (p < 0.0005) and the difference between the subjective and objective refraction. In 99.2% of the measurements, visual values were within one decimal line of each other.

Conclusion: The Nidek AR-360A autorefractometer is an accurate tool for determining the refraction and VA in a clinical screening trial.