Collagenolytic activity of alkali-burned corneas of rabbits was investigated using a tissue-culture assay technique. The technique was standardized, and in every instance, tissues from the immediate vicinity of the ulcers or perforations showed substantial collagenase production, while generally, tissues more than 2 mm away from the lesions were free of enzyme activity.
Brown SI, Weller CA, Wassermann HE. Collagenolytic Activity of Alkali-Burned Corneas. Arch Ophthalmol. 1969;81(3):370-373. doi:10.1001/archopht.1969.00990010372015