Abstract:
To determine whether photopolymerized methacrylates can functionally seal corneal wounds and if they are comparable to sutures, as current adhesives (cyanoacrylates; fibrin) suffer from a rough surface and difficult application.
Sclera of fresh porcine eyes were sealed with viscous cyanoacrylate. The anterior chamber was cannulated and infused with saline. The rate of fluid egress was measured as a function of intraocular pressure (IOP) for 5 eyes with no incision; 5 eyes with a 5 mm incision closed with simple interrupted 10–0 nylon sutures, and 5 eyes with a 5 mm incision closed with a proprietary adhesive containing hydroxyethylmethacrylate. Bursting strength was measured by recording IOP at wound failure. Subsequently, tensile strength of the sutured incisions and adhesive incisions were compared to porcine cornea by pulling strips of cornea in tension until failure.
At an IOP of 30 cm H20, fluid egress was 2.3 ul/min for control eyes, 12.7 ul/min for sutured eyes and 3.2 ul/min for adhesive eyes. While all eyes remained clinically Siedel negative, there was a significant decrease in permeability for wounds closed with light cured adhesive vs. sutures (p < 0.05). There was no significant difference between control eyes and adhesive eyes (p = 0.56). The difference between adhesive and sutures became more pronounced at higher IOP. The maximum IOP sustained before failure was 73.3 cm/H20 in sutured eyes and 140 cm/H20 in adhesive eyes (p < 0.01). The tensile strength for sutured incisions was 0.46 N/mm2, for adhesive incisions 0.37 N/mm2, and the cohesive strength for porcine cornea 0.57 N/mm2. There was no significant difference between these groups.
Light cured methacrylates are superior to sutures in terms of wound permeability and bursting strength. Tensile strength of the adhesive bond is comparable to sutured incisions and uncut cornea. The light cured adhesive provides a smooth ocular surface and ease of application that is far greater than cyanoacrylates or sutures.
Keywords: transplantation • trauma • wound healing