Year: 2026
Type: article
Study design: Observational Study
Abstract: Purpose To compare refractive measurements, keratometry, pachymetry, and tonometry between two commercially available systems: Visionix VX650 (Luneau Technologies, France) and Nidek TonoRef III (Nidek, France). Methods This is a retrospective cohort study in which 415 valid eye measurements of 206 patients were obtained using both machines. Three groups were created: 1. The refraction group included 206 patients (400 eyes); 2. The keratometry group included 147 patients (293 eyes); 3. The pachymetry and tonometry group included 123 patients (245 eyes). To test agreement, each subject was measured once with each instrument. Results In the first group, there was no statistically significant difference in sphere measurements (p = 0.072), but there was a significant difference in cylinder power (p = 0.014) and axis (p = 0.009) measurements. The second group had a strongly significant difference between keratometry power measurements (p = 2.784 × 10 −5 ), but no statistically significant difference in mean keratometric axis measurements (p = 0.191). The third group found a strongly significant difference for pachymetry (p = 9.632 × 10 -10 ), but none for corrected tonometry (p = 0.064). Discussion The two devices demonstrated variable levels of agreement depending on the parameter analyzed. Nevertheless, both machines have merit in measuring refraction and detecting glaucoma. Conclusion Good agreement between the two instruments was found for sphere power and corrected tonometry. Nevertheless, differences in refractive and keratometric axis measurements, as well as pachymetry, highlight the fact that the same instrument should be used for follow-up.
Source: JFO Open Ophthalmology
Language: English
Subfield: Ophthalmology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,680
OpenAlex ID: W7202300612