Corneal densitometry in healthy patients measured with scheimpflug pentacam® camera

Purpose: To evaluate the normal values of corneal densitometry of healthy subjects in order to assess a normative database. Methods: This retrospective non-randomized single-center was conducted on healthy subjects who performed a topographic examination before refractive surgery and showed no corneal or other ocular pathology. A slit-lamp examination was carried out before Scheimpflug topography scanning to exclude any corneal opacity. Parametric paired Student t-test and non-parametric Kruskal-Wallis test with Bonferroni correction was performed. Results: 311 healthy patients with a mean age of 39.4 +/- 15.7 [11; 82] years at the time of the inclusion were recruited. Mean total densitometry was 18.8 +/- 3.2 [13.2; 33.7] and a statistical difference was found between each layer and corneal rings. Graph distribution of the average corneal densitometry represents a gentle slope with a mild peak in the anterior stroma. Anterior densitometry was significantly higher than central and posterior densitometry (25.2+/- 4.4 [17.3; 46.2] vs 16.6+/- 3.1 [11.5; 31.2], p<0.0001 and 14.8 +/- 2.8 [9.6; 27.8], p<0.0001 respectively). Strong correlation was calculated between age and corneal densitometry, with a significant increase in corneal density with age (p<0.0001). Conclusion: We propose in this study Scheimpflug database of normal corneal densitometry. This can provide a useful objective measure of corneal transparency and may help routine clinical practice.