Continuous Measurement of Corneal Dehydration With Online Optical Coherence Pachymetry

Purpose: 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. Methods: 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. Results: 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. Conclusions: Online OCP was suitable for continuous measurements of corneal changes caused by dehydration. These dehydration effects should be particularly considered in refractive corneal surgery.

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