A photopolymerized sealant for corneal lacerations

Purpose. To determine whether a novel photocrosslinkable polymer synthesized from hyaluronic acid would seal experimental full-thickness corneal lacerations in a rabbit model. Methods. A solution of hyaluronic acid was modified with methacrylate groups (HA-MA), precipitated, dried, reconstituted in an aqueous solution, and sterilized before use. The viscous polymer solution was applied to 38 of 43 experimental corneal lacerations in rabbits and subsequently irradiated with a low-intensity argon laser beam to produce a clear flexible polysaccharide hydrogel patch. The ability of this sealant to repair corneal lacerations was evaluated in four types of full-thickness, 3-mm corneal wounds (linear, linear + epithelium removed. stellate, and stellate + epithelium removed). Slit-lamp examinations, measurements of intraocular pressure, Seidel tests, and histologic studies were performed at selected intervals to evaluate the wound and determine the rate of healing. Results. Corneal perforations were completely sealed and the anterior chambers had reformed by 6 hours in HA-MA-treated eyes. There was no evidence of leakage at this or later times in 37 of the 38 eyes. Intraocular pressure had risen to near-normal levels by day 7 in all four groups, and the sealant was still present in most eyes at clay 7. In contrast, the anterior chambers did not re-form in control eyes (five) with untreated perforations because of aqueous leakage through the wounds. Minimal inflammation was observed clinically or in histologic sections of treated corneas. There was extensive proliferation of stromal cells and formation of new extracellular matrix at the wound edges, which became tightly adherent between days 4 and 7. Conclusion. Our novel photocrosslinkable methacrylated hyaluronan polymer sealed 97% (37/38) of the experimental corneal lacerations. HA-MA may prove useful for sealing corneal lacerations in patients and for other sutureless ophthalmic surgical procedures.