Continuous Measurement of Corneal Dehydration With Online Optical Coherence Pachymetry

Abstract

Online optical coherence pachymetry (online OCP) allows continuous central corneal thickness measurements over time. In this study, the effect of dehydration on corneal tissue was investigated with online OCP. Twelve eyes of 11 patients were examined with online OCP, and the central corneal thickness was registered over 5 minutes after insertion of an eyelid speculum. Online OCP measurements revealed no decrease in reproducibility after 5 minutes of dehydration. The initial mean central corneal thickness was 538 ± 48 μm. After 5 minutes the central corneal thickness decreased to 483 ± 43 μm (P = 0.001). This corresponded to a mean corneal thinning of 55 ± 4 μm (10.2%) at a rate of 0.19 μm/s. Online OCP was suitable for continuous measurements of corneal changes caused by dehydration. These dehydration effects should be particularly considered in refractive corneal surgery.