Age-Related Corneal Transparency Changes Evaluated With an Alternative Method to Corneal Densitometry

Purpose: To compare densitometry distribution analysis (DDA), a platform-independent method to assess corneal transparency, with traditional corneal densitometry. Methods: A total of 196 healthy participants aged 43.3 +/- 18.0 years (range 18-79 years) were recruited for assessment. All participants were assessed using the corneal densitometry analysis add-on to the standard software of the Oculus Pentacam HR. In addition, the Scheimpflug image corresponding to the horizontal meridian of each participant was exported for further analysis. For each image, corneal pixel intensities were statistically modeled. The estimated output parameters, alpha and beta, were compared with the corresponding densitometry values. The analysis was performed considering 3 concentric areas and 3 layers defined at fixed corneal depths. To demonstrate the platform independence of the DDA method, a randomly selected subset of 80 participants also had their eye measured with Oculus Corvis ST. Results: alpha and beta were found to be well correlated with densitometry, especially alpha (overall cornea; r = 0.89, P < 0.001), independent of the corneal region investigated. Changes in alpha, beta, and corneal densitometry were correlated with age. Conclusions: In this work, we presented the relationship of DDA with age and traditional corneal densitometry. The alpha and beta parameters, the output of DDA, are platform independent and can be used to investigate corneal clarity objectively.