Abstract
Purpose:
to determine the specificity and sensitivity of keratoconus progression measured with these two parameters the regularity of the pachymetric map (RPM) and the Index of height decentration (IHD).
Methods:
Sequential topometric measurements spaced by six months, utilizing the Pentacam device (Scheimpflug imaging) were conducted in 100 keratoconic eyes. The indices RPM and IHD were correlated with keratometry, UDVA, CDVA and minimal pachymetry with 6 years follow-up.
Results:
Distortion of the RPM and increase of the IHD appeared to be the first markers of KCN progression in all cases, preceding by an average of 18 (± 4.5) months the UDVA, CDVA and keratometric changes of over 1 diopter.
Conclusions:
Monitoring RPM and IHD may be a useful earlier diagnostic tool for ectasia progression and postoperative LASIK stability. It may serve as a new definition of ectasia progression.
Keywords: 574 keratoconus •
677 refractive error development •
733 topography