Background - PorCORA
For over five years, MB Research Scientists have been developing assay methods in order to create a
cost-effective protocol to offer you a viable alternative to the Draize Rabbit Eye Test.
PorCORA is similar to the BCOP, but by culturing
the excised corneas for up to 3 weeks, the reversal of damage to the cornea can be measured over time
and the "Days to Clear" can be determined.
Assessment of Corneal Damage
Fluorescent dye stain retention by corneal epithelium has proven to be an effective tool in the assessment of ocular damage after exposure to irritants. This method is non-destructive and allows for re-staining
of the same tissue over the course of the study. The area of damage is clearly defined and easily observed almost immediately after staining.
Initial ocular irritation and subsequent opacities are assessed and scored according to the PorCORA Fluorescent Dye Stain Retention Scoring System. Scoring of the area of damage is done by visually assessing the percentage of damage to the cornea shown by the retention of fluorescent dye and assigning a corresponding score.
PorCORA Fluorescent Dye Stain Retention Scoring System *
*Based upon Draize, J.H., et al., J. Pharm. Exp. Ther., 82:377-390, 1944.
- 0 - No Stain Retention
- 1 - One quarter (or less) but greater than zero.
- 2 - Greater than one quarter but less than one half.
- 3 - Greater than one half, but less than three quarters.
- 4 - Greater than three quarters but less than 100%.