Vertex distance variability of the Vision-S™ 700 refractors in normal population

Variabilidade da distância vértice do refrator Vision-S™ 700 em uma população normal

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.

Keywords:
Refraction ocular; Refractive errors; Refractometry; Refractive surgical procedures; Vertex distance