Rasterstereography-based classification of normal corneas

J Cataract Refract Surg. 1997 Mar;23(2):222-30. doi: 10.1016/s0886-3350(97)80345-8.


Purpose: To attempt to classify the topographic patterns identified by rasterstereography in a population with normal corneas.

Setting: Tulane Medical Center Clinic, New Orleans, Louisiana.

Methods: Corneal elevation pictures of 100 eyes of 50 volunteers were taken using the PAR Corneal Topography System. The volunteers had no history of eye injury, disease, or surgery, and none wore contact lenses. Three observers independently assigned the images to one of five subgroups.

Results: Five categories were identified: unclassified, regular ridge, irregular ridge, incomplete ridge, and island. There were significant statistical differences in the degree of astigmatism between the irregular ridge and incomplete ridge groups (P = .0419) and between the irregular ridge and island groups (P = .017).

Conclusion: The topographic patterns identified by rasterstereography in normal corneas can be classified into five distinct groups.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Cornea / anatomy & histology*
  • Female
  • Humans
  • Image Processing, Computer-Assisted / classification*
  • Image Processing, Computer-Assisted / methods*
  • Male
  • Middle Aged
  • Prospective Studies
  • Reference Values