Abstract

Background: The Plusoptix Vision Screener™ (PVS) is a new non-cycloplegic videoretinoscopy autorefractor. Refractive accuracy may affect its performance as a screening tool.

Aims: Study 1: To determine intra- and interobserver variability of PVS measurements. Study 2: To compare PVS measurements with gold standard manual cycloplegic retinoscopy (MCR).

Methods: Study 1: PVS refraction of 103 children with mean (SD) age 5.5 (0.6) years by two observers. Study 2: PVS and MCR refraction of 126 children with mean (SD) age 5.5 (1.5) years, including 43 children with manifest strabismus ≥ 5PD, comparing mean spherical equivalent (MSE) and Jackson cross cylinders J0 and J45.

Results: Study 1: Repeatability coefficients (observer 1): MSE: 0.63D, J0: 0.24D, J45: 0.18 D; those of observer 2 were nearly identical. Mean difference (95% limits of agreement) between the two observers for MSE, J0 and J45 were, respectively, 0.03 (-0.62 to 0.68D), -0.008 (-0.25 to 0.23 D), 0.013 (–0.18 to 0.20) D. Study 2: MSE tended to be lower on PVS than MCR, with differences of up to 8.00 D. Less than 20% of values were within +/-0.50D of each other. Agreement was better for J0 and J45. Strabismus was associated with an odds ratio of 3.7 (95% CI: 1.3 to 10.5) of the PVS failing to obtain a reading.

Conclusions: The PVS may underestimate children’s refractive error.