98th Annual Meeting DOG 2000

K 592

Corneal curvature measurement with optical coherence tomography

C. Scholz, C. Wirbelauer*, P. Koch, R. Engelhardt

Introduction: Optical coherence Tomography (OCT) allows to perform quantitative non invasive measurements of human cornea in vivo. We evaluated the accuracy and consistency of this method.

Methods: With a prototype OCT-device adapted to a regular slitlamp we performed curvature measurement on steel balls with known diameter and then on 15 patients. Our system calculated the curvature computer aided from the data of a two dimensional cross-section of the anterior eye segment. The results were compared with the results of other devices (ophthalmometer, Zeiss; EH-290, Alcon).

Results: We investigated steel balls with different diameters corresponding to an optical power of 23 up to 85 diopters. The measurements correlated quite well with the expected values (r=0,99; P<0,0001). On patients we performed the measurement with a reduced number of lines to reduce motion artifacts. We had an acquisition time of 0.3 s/frame. < /FONT>

Conclusion: Optical coherence tomography is an useful tool for corneal curvature measurements. The results corresponded to other methods. Shorter acquisition time could lead to a higher reliability and accuracy. Furthermore OCT allows access to corneal pachymetry and the curvature between cornea and anterior chamber, so the optical power of the cornea could be determined precisely.

Medizinisches Laserzentrum Lübeck GmbH; 
*Augenklinik der Medizinischen Universität zu Lübeck