Corneal densitometry in high myopia

Background: To investigate corneal densitometry values obtained using Scheimpflug tomography in normal and highly myopic (HM) eyes and to assess the differences in densitometry values between them. Methods: Highly myopic and normal corneas were examined using the Pentacam Scheimpflug imaging system. Corneal densitometry was automatically performed over a 12-mm diameter area, which was divided on the basis of annular concentric zones (0-2 mm, 2-6 mm, 6-10 mm, 10-12 mm, total diameter) and depth (anterior layer: inner 120 mu m; center layer: from 120 mu m to the last 60 mu m; posterior layer: last 60 mu m; total corneal thickness). Results: A total of 100 normal and 100 HM eyes were enrolled in this study. Upon total corneal thickness densitometry, the HM group was found to have significantly lower values compared with the normal group in 4 annuli, including the 2 mm central zone, 2-6 mm zone, 6-10 mm zone, and 0-12 mm total diameter. Upon anterior layer densitometry, the HM group demonstrated statistically lower values in the 2-6 mm and 6-10 mm zones. Upon densitometry of the central and posterior layers, the HM group was found to have lower values in all annuli. Conclusions: The densitometry map reveals that light backscatter was lower in most portions of the HM cornea than in the normal cornea.