Quantification of corneal transparency in post‐mortem human corneas using laser scatter image analysis

Abstract

Background

The cornea is a highly transparent structure covering the anterior one‐fifth of the eyeball. The suitability of post‐mortem donor corneas for keratoplasty is currently qualitatively assessed. This makes inferences prone to bias and subjective variability. This study aimed to develop a simple, feasible and cost‐effective method to quantify corneal transparency.

Methods

An artificial anterior chamber was modified to provide a central transparent passage and a standardised pressure segment. All corneas graded ‘fair’ were included in this study. The corneoscleral buttons were mounted on the modified artificial anterior chamber. The mounted chamber was held in a horizontal position at a fixed distance from a white projection screen. The laser source was placed in alignment with an artificial anterior chamber so that it passed through the centre of the cornea. A camera mounted on a tripod stand was placed at a prefixed distance. An image of the scattered laser spot that formed after the laser passed through the mounted cornea on the screen was captured with a single digital camera and standardised settings. Image analysis was performed using ImageJ, an open platform for scientific image analysis. The average red pixel intensity, max intensity, and full‐width half max were calculated.

Results

The average red intensity was 132.45 ± 6.65 SD. The mean for max intensity was 51.1 ± 3.78 SD and the full‐width half max 787.7 ± 84.7 SD.

Conclusion

Laser quantification is a simple and cost‐effective method of quantifying corneal transparency. The study lends proof to the principle involved.

Key words:

• cornea
• laser
• stroma
• transparency