Clinical validation of a fast binocular subjective refraction algorithm
Document typeMaster thesis
Rights accessRestricted access - author's decision
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.
En col·laboració amb la Universitat Autònoma de Barcelona (UAB), la Universitat de Barcelona (UB) i l’Institut de Ciències Fotòniques (ICFO)
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