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Published on: September 16, 2025
Evaluation of a New Algorithm-Based Approach in Subjective Refraction
Imene Salah-Mabed1, Vincent Péan1, Damien Gatinel1
1Department of Anterior Segment and Refractive Surgery, Rothschild Foundation, Paris, France.
Purpose:
The aim of this study was to evaluate a new algorithm-based approach in subjective refraction by comparing the refractions obtained by a professional expert with those obtained using the SiviewExam Expert system on a large population.
Methods:
Two subjective refraction methods were compared prospectively on patients visiting Rothschild Foundation between October 2022 and May 2023: (i) A manual refraction performed by an expert using a standardized method and (ii) an automated one with the SiviewExam Expert system. Outcomes of the two subjective refractions were compared using a power vector analysis method. Power vectors are a geometric representation of spherocylindrical refractive errors in 3 fundamental dioptric components: M (M = S + C/2), J0 (J0 = (-C/2) cos (2α) at an axis of α = 0 = 180°), and J45 (J45 = (-C/2) sin (2α) at an axis of α = 45°). At the end of the examination, the SiviewExam Expert system provided a report that has been analyzed as well.
Results:
A total of 107 patients, with a mean age of 35.7 ± 11.9 years (ranging from 19 to 69 years) were included in the study. The mean SE was -2.10 ± 3.37 D (ranging from -11 D to +7.13 D). The mean differences have shown that there were no bias between the measurements for M (0.01 D, -0.04-0.07 D) and J45 (0.009 D, -0.01-0.03 D) and a clinically negligible bias (0.05 D, -0.08--0.02 D) in the estimation of J0. The limits of agreement were -0.54 D (lower limit: -0.63--0.44) to 0.56 D (upper limit: 0.47-0.65), -0.22 D (lower limit: -0.26 to -0.18) to 0.24 D (upper limit: 0.20-0.27), -0.34 D (lower limit: -0.39 to -0.29) to 0.25 D (upper limit: 0.20 to 0.30) for M, J45, and J0, respectively, and were significantly lower than the expected inter-examiner variability of 0.7 D. Finally, the report provided by the SiviewExam Expert system was found to be accurate according to the expert in 100% of the cases.
Conclusion:
Our outcomes show that in a large adult population of over 100 patients with a wide range of ametropias, there were no statistically significant differences in the results for M, J0, and J45 between the two refraction methods, indicating that we could reasonably clinically consider the SiviewExam Expert system examination comparable with the one conducted by an expert.
