Abstract
Purpose: :
The VMax PSF Refractor incorporates point spread function (PSF) technology, enabling it to reduce or eliminate higher order aberrations through a subjective refraction. The aim of this study was to compare measurements obtained with the Vmax Subjective PSF Refractor (Vmax Vision, Maitland, FL) with standard manifest refraction measurements, based on visual acuity results. Patient satisfaction was also assessed.
Methods: :
Nine hundred patients at 5 clinical sites were enrolled in the study. Each patient underwent subjective PSF refraction and phoropter manifest refraction, and visual acuity was recorded. The duration of each examination was also noted. Patients were asked to assess their preference for the procedure using a Likert scale according to the following categories: speed of exam, ease of use, fatigue, and ability to respond confidently.
Results: :
Compared to standard phoropter manifest refraction, the PSF refractor obtained equal or better visual acuity results (63% and 28%, respectively; p <0.001). Ninety percent of patients preferred the PSF refraction to the manifest refraction. Overall, PSF refraction was found to be faster, easier to use, and less tiring for patients.
Conclusions: :
The Vmax PSF refractor is a useful clinical instrument that provides better or equal in accuracy and reliability in refractive end points than a standard manifest refraction using a phoropter. The VMax device provides refraction data in 0.05 D increments and also reduces higher-order aberrations not addressed by other techniques. In a large multi-center trial, patients preferred the PSF refractor to standard refraction techniques.
Keywords: refraction • visual acuity • aberrations