Clinical validation of a fast binocular subjective refraction algorithm

En col·laboració amb la Universitat Autònoma de Barcelona (UAB), la Universitat de Barcelona (UB) i l’Institut de Ciències Fotòniques (ICFO)The purpose of this study is to investigate a new algorithm to perform an automated non-cycloplegic refraction in adults. In order to carry on the study fifty healthy subjects were measured twice (test-retest) with the new automated subjective refraction (ASR) method and with the conventional clinician subjective refraction (CSR) procedure. Objective refraction (OR) is also measured with the autorefractor Grand Seiko WAM-5500. The new subjective refraction procedure is mainly based on the root finding bisection algorithm and on the Euclidean distances among power vectors. The algorithm is implemented on a computer that is synchronized with a custom-made motorized phoropter. Main outcome measures: spherical equivalent (M) and Jackson cross-cylinder (J0 and J45). Repeatability is assessed with the within-subject standard deviation (Sw) and agreement is assessed with the limits of agreement. The results showed that the first implementation of the algorithm is a potential novel method of performing non-cycloplegic subjective refraction in adults without clinician support. Although it presents some limitations that warrant further research and it still should be tested in a wider population in terms of age, refraction and different ocular conditions, this method can contribute to improve the access to primary eye care services in developing countries