Evaluation of the auto‐refraction function of the Nidek OPD‐Scan III

Abstract

BackgroundThe aim was to evaluate the validity and repeatability of the auto‐refraction function of the Nidek OPD‐Scan III (Nidek Technologies, Gamagori, Japan) compared with non‐cycloplegic subjective refraction. The Nidek OPD‐Scan III is a new aberrometer/corneal topographer workstation based on the skiascopy principle. It combines a wavefront aberrometer, topographer, autorefractor, auto keratometer and pupillometer/pupillographer.MethodsObjective refraction results obtained using the Nidek OPD‐Scan III were compared with non‐cycloplegic subjective refraction for 108 eyes of 54 participants (29 female) with a mean age of 23.7 ± 9.5 years. Intra‐session and inter‐session variability were assessed on 14 subjects (28 eyes).ResultsThe idek Nidek OPD‐Scan III gave slightly more negative readings than results obtained by subjective refraction (Nidek mean difference ‐0.19 ± 0.36 DS, p < 0.01 for sphere; ‐0.19 ± 0.35 DS, p < 0.01 for mean spherical equivalent; ‐0.002 ± 0.23 DC, p = 0.91 for cylinder; ‐0.06 ± 0.38 DC, p = 0.30 for J0 and ‐0.36 ± 0.31 DC for J45, p = 0.29). Auto‐refractor results for 74 per cent of spherical readings and 60 per cent of cylindrical powers were within ± 0.25 of subjective refraction. There was high intra‐session and inter‐session repeatability for all parameters; 90 per cent of inter‐session repeatability results were within 0.25 D.ConclusionThe Nidek OPD‐Scan III gives valid and repeatable measures of objective refraction when compared with non‐cycloplegic subjective refraction.