[Keratoconus: correlations between clinical aspects and Orbscan evaluations].

PURPOSE: To look for potential correlations between clinical and topographical aspects of keratoconus evaluated by Orbscan (Chauvin-Bausch & Lomb).

METHODS

We analyzed 228 keratoconic eyes in a retrospective study over a period of 16 months. The best corrected visual acuity (BCVA) and the corneal opacities were correlated with 26 topographical parameters evaluated by Orbscan.

RESULTS

The maximal keratometry is the parameter that correlated best with clinical aspects. The other well-correlated keratometric parameters were the SimKmax and the Mean Power in the 3-mm zone. The distance between the central point and the point with maximal keratometry is the best localization parameter. The maximal amplitude of elevation on the anterior elevation map and the value of the minimal pachymetry also correlate well with the BCVA. The results were nevertheless quite scattered, but could be explained by bias, which will be corrected in further prospective studies.

CONCLUSION

Orbscan provides useful information to assess the topography of keratoconus. Some parameters correlate well with clinical aspects, which may lead to a new clinico-topographical classification. More investigations are necessary to reduce the scattering of the results.