Pentacam Scheimpflug evaluation of corneal volume after LASIK.

PURPOSE: To assess the change in corneal volume and laser ablation volume over time after LASIK using a rotating Scheimpflug camera.

METHODS

Twenty-six patients (49 eyes) underwent LASIK. Pentacam Scheimpflug measurements were performed pre- and postoperatively at 1, 3, 7, 15, and 30 days. Central corneal thickness, total corneal volume (10-mm diameter), and partial corneal volumes (3, 5, and 7 mm) based on the apex of the cornea, were measured. Main outcome measures were differences between pre- and postoperative volume measurements of total and partial corneal regions, volume changes over time postoperatively, and comparison between laser ablation volume and corneal volume.

RESULTS

A strong linear relationship was noted between spherical equivalent refraction and laser ablation volume (r = -0.931, P < .0001). Furthermore, 30 days after LASIK, a strong linear relationship was noted between planned thickness and achieved thickness (r = 0.9457, P < .001). Corneal volumes for 3-, 5-, and 7-mm diameter regions significantly decreased over time postoperatively (one-way analysis of variance, P < .05).

CONCLUSIONS

Alterations in corneal volume correlated with laser ablation volume when the diameter of the region considered was 3, 5, or 7 mm from the corneal apex.