Noncontact corneal pachymetry with slit lamp-adapted optical coherence tomography

Am J Ophthalmol. 2002 Apr;133(4):444-50. doi: 10.1016/s0002-9394(01)01425-8.


Purpose: The purpose of this study was to determine the accuracy, the reproducibility, and the limits of agreement of noncontact central corneal thickness measurement with slit lamp-adapted optical coherence tomography (OCT).

Design: Nonrandomized comparative clinical trial.

Methods: In a prospective comparative observational study, a total of 108 consecutive patients (108 eyes) with normal corneas (92 eyes) and different corneal alterations (16 eyes) participated. Six sequential measurements of the central corneal thickness with slit lamp-adapted OCT and with ultrasound (US) pachymetry at 1640 ms(-1) were performed. The main outcome measures were accuracy, reproducibility assessed with precision and coefficient of variation (CV), and limits of agreement of central corneal thickness measurement.

Results: The mean central corneal thickness values were 541 +/- 43 microm (OCT) and 549 +/- 44 microm (US) with a mean precision of +/- 5.8 microm (CV 1.08%) and of +/- 4.0 microm (CV 0.73%), respectively. The method comparison revealed equivalence (+/- 2SD) in the 5% range with a mean difference between both methods of 7.9 microm (1.45%). The relative error was 8.7 microm (1.6%), which corresponded to limits of agreement (+/- 2SD) ranging from -9.5 microm to 25.3 microm.

Conclusions: Central corneal pachymetry with slit lamp-adapted OCT revealed, for clinical purposes, an excellent accuracy and reproducibility with a high degree of agreement compared with US pachymetry. Thus, the presented OCT system seems to be a promising diagnostic modality to objectively measure corneal thickness in a convenient noncontact mode.

Publication types

  • Clinical Trial
  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cornea / anatomy & histology*
  • Cornea / diagnostic imaging
  • Cornea / pathology
  • Corneal Diseases / pathology
  • Diagnostic Techniques, Ophthalmological*
  • Female
  • Humans
  • Interferometry
  • Light
  • Male
  • Middle Aged
  • Prospective Studies
  • Reproducibility of Results
  • Tomography / methods
  • Ultrasonography