Corneal elevation and thickness in relation to the refractive status measured with the Pentacam Scheimpflug system

Abstract

Purpose: To prospectively evaluate the elevation and thickness data in patients with different types of refractive errors.

Setting: Department of Ophthalmology, Ankara University Faculty of Medicine, Ankara, Turkey.

Methods: After the refractive errors in 215 consecutive patients were determined, corneal topography measurements with the Pentacam Scheimpflug system were taken in the right eye of all patients and the right eye of 31 healthy emmetropic volunteers. The eyes with refractive errors were assigned to 1 of the following 4 groups: myopia, myopic astigmatism, high myopia, and hyperopia. The means of the parameters of 3 Pentacam measurements were evaluated and compared.

Results: Eyes with high myopia had significantly lower mean corneal thickness and volume measurements and higher mean anterior chamber depth (ACD) and anterior chamber volume (ACV) measurements than eyes in the other groups. The mean ACD, ACV, and anterior chamber angle were significantly lower in hyperopic eyes than in the other groups. The mean keratometry readings were statistically significantly flatter in the hyperopia group than in the other 4 groups.

Conclusions: Eyes with high myopia had thinner corneas and deeper anterior chambers than emmetropic eyes and eyes in the other ametropic groups. Excluding eyes with hyperopia, which had significantly flat anterior and posterior elevation measurements, the elevation measurements in eyes with myopic refractive errors did not differ from each other or from those in emmetropic eyes. These findings may help clinicians and refractive surgeons using the Pentacam to better define normal from abnormal in the clinical setting.