The Orbscan acoustic (correction) factor for central corneal thickness measures of normal human corneas

Orbscan scanning-slit optical pachymetry was introduced over a decade ago and yielded higher central corneal thickness (CCT) values to the “gold standard” of contact ultrasound pachymetry (U/S). An acoustic correction factor (AF) was introduced later to compensate for this difference. The goal of this review was to assess the magnitude and consistency of the difference, as well as to assess how useful the AF had been.