Exploring Wavefront Refraction

Signature Grand, Davie, Florida, USA

Objective. This is a report on the potential reliability of refractions derived from wavefront aberration measurement. Background. For the last several years there has been interest in fully correcting all aspects of refractive errors (higher order aberrations as well the lower order aberrations). It has been suggested that objective refractions derived from wavefront aberrometry (ADR) could replace subjective refractions (SR). Methods. Optometry students had the monocular SR of their right eye determined using standard optometric techniques by an experienced clinician. Another researcher used the COAS wavefront analyzer to generate a spectacle refraction on the same eye. The prescriptions were converted into power vectors (PV) and compared to each other. We looked at the correlation between measurements for various pupil diameters and also looked at the absolute differences to find what percent of ADR could actually be used by a typical patient. Results. Correlation between the SR and the ADR was good for all pupil sizes. However, only roughly 1/3 of the ADR based PVs were within or equal to 0.25D of the PVs for the SR. If a correction factor is applied, it approaches 50% accuracy. Conclusion. ADRs tend to be over-minused by a constant amount. Even when that is factored in, the results don’t agree with SR closely enough to suggest clinical usefulness. An additional compromising factor would be the lack of binocular balance with the ADR. The specific pupil diameter used for analysis makes only a small difference in accuracy.