Ophthalmologist Stephen Kaufman identifies the cause of these issues being the rabbit is an inappropriate and inaccurate model for human ocular damage. The rabbit is used because they are inexpensive, docile and have large eyes. The anatomical differences between a human and rabbit eyelid include a more permeable epithelial (surface) layer, thicker bowman’s membrane, higher pain threshold, less efficient tearing system, a nictitating membrane (third eyelid), thinner corneal, higher susceptibility of alkaline materials and a larger cornea. These physiological differences between rabbit and humans demonstrate the cause of inaccurate and varied results. An experiment was conducted by comparing the results of 281 human ocular toxicity exposures to 14 house products with findings from the Draize test. The closest connection with the human experiences and the Draize test was a factor of 18 however the largest was 250. Therefore the Draize test poorly predicted the human eye toxicity (Kaufman, 2005). The scoring of the rabbit’s eye and skin damage is highly subjective therefore results vary between laboratories as well as within the same laboratory (PETA, 2015). Another experiment was conducted by toxicologists Carrol Weil and Robert Scala of Carnegie Mellon University, which included a comparative analysis of three test substances by …show more content…
The test became a governmentally endorsed method to evaluate possible irritants in or around the eyes (Wilhelmus, 2001) and has been the standard procedure for making ocular safety assessments (Kapis & Gad, 1993). In some countries it is a legal requirement for the Draize test to be done on substances that may come into contact with the eyes (ANSCCART, 2015). Despite the rabbit eye being anatomically different, their eyes possess a higher sensitivity and greater susceptibility to alkaline materials compared to the human eye therefore making results easy to interpret (Kaufman, 2005). The test has been modified slightly under the Code of Federal Regulations that the rabbit being examined may be used for four or six patch tests and six animals to be tested for the potential irritant. The test itself is able to be modified. In order to clearly observe the skin reaction, the test can be changed to use newly-shaved skin for substances that have the potential make direct contact with eyes and is observed at 4, 24, and 72 hours after application. The skin test can also be used by undertaking the Draize test procedure on consenting humans however proper ethical considerations must first be addressed. The Draize test scale can be modified to