Rev Bras Oftalmol.2024;83:e0036
Vertex distance variability of the Vision-S™ 700 refractors in normal population
DOI: 10.37039/1982.8551.20240036
ABSTRACT
Objective:
To study vertex-optical distance variation and estimate its impact on manifest refraction.
Methods:
Prospective study in a private clinic using the Vision-S™ 700 with five forehead positions. Forehead on the third position showed the closest vertex-optical distance of 12mm.
Results:
Analysis of 52 eyes from 26 patients revealed mean differences in vertex-optical distance of 12.25mm (right eye) and 11.75mm (left eye). A 2mm change in vertex-optical distance resulted in a 0.05D change for a 5D spherical equivalent and 0.20D for a 10D equivalent.
Conclusion:
Vertex-optical distance varies among patients and is influenced by forehead adjustment. These variations impact refraction accuracy and treatment evaluation. Adjusting the forehead to the third position on the Vision-S™ 700 is recommended.
