Krill protease effects on wound healing after corneal alkali burn

Purpose. To study the effect of a novel protease in the development and pro gression of corneal ulceration secondary to alkali burning. Methods. By usi ng a 4N alkali burn model of corneal ulceration in rabbits, the effects and efficacy of topical application of a novel protease (PHM-101) capable of d egrading metalloproteinases was studied for 28 days of treatment and 7 days off treatment for its effect on corneal ulceration and recurrent erosion. Results. At day 28, both the protease- and placebo-treated groups had diffe rent numbers of eyes showing reepithelialization [nine (45%) of 20 and six (33%) of 18, respectively]. By day 35 the protease-treated group had signif icantly fewer recurrent epithelial defects [two (13%) of 15 vs. eight (61%) of 13; p = 0.02]. Similarly, at day 35 the protease treated group showed s ignificantly less corneal ulceration [two (13%) of 15 vs, six (46%) of 13; p = 0.02], and those ulcers were of a lesser severity (three units vs. 17.7 6 units). No difference was found in the degree of stromal edema or neovasc ularization, nor was there any difference in histopathologic characteristic s of inflammatory cell infiltration and corneal scarring. Conclusion. We co nclude that this novel protease is efficient in reducing recurrent corneal epithelial defects and stromal ulceration after alkali burning.