Scleral Attachment of Extraocular Muscle using a Stitch Combined with Tissue Adhesive in Rabbits

ABSTRACT

In experimental sutureless muscle surgery with tissue adhesives, current materials have inadequate adhesive strength in the early postoperative period.We performed a modified muscle surgery using a stitch combined with Tisseel (Immuno AG, Vienna, Austria)in order to evaluate the adhesive strengh as a replacement for conventional suture techniques in muscle surgery. Thirty eyes of 15 rabbits were used.We recessed superior and inferior rectus muscles by three different methods, Tisseel only, a stitch with Tisseel, and a stitch only, in each group of 5 rabbits.Conjunctival incisions were closed with the remaining Tisseel in 7 rabbits, and with vicryl in 8 rabbits. Tensile strength of the scleral reattachment site was measured and conjunctival closure was examined by slit-lamp biomicroscopy, at intervals of 1 hour, 12 hours, 1 day, 3 days and 5 days. The strengths of a stitch with Tisseel at each interval were 83.25 +/-1 4 .0 6 gm, 137.50 +/-22.88 gm, 169.75 +/-23.95 gm, 151.50 +/-41.99 gm, and 265.50 +/- 25.01 gm, respectively.The strengths of Tisseel alone were 61.50 +/-2 0 .2 1 gm, 101.50 +/-11.00 gm, 113.25 +/-28.69 gm, 120.50 +/-18.36 gm, and 222.75 +/- 57.67 gm.They were 52.25 +/-24.85 gm, 89.50 +/-16.05 gm, 130.75 +/-21.98 gm, 1 5 3 .7 5 +/-30.35 gm, and 261.50 +/-60.47 gm at each interval in rabbits with a stitch alone. These results showed that the tensile strengths of a stitch with Tisseel were stronger than those of the other two methods up to 1 day after surgery.Even at postoperative 12 hours, the strength was more than 130 gm which was strong enough for scleral attachment.All of the conjunctival closures with Tisseel were well maintained without any complication up to 5 days, the same as vicryl sutures. In conclusion, this study revealed that muscle attachment to the sclera by a stitch with Tisseel was simpler and safer than classical sutures with reduced risk of sclera perforation.Its strong tensile strength at early postoperative days suggests that the method might be considered as an alternative method to classical reattachment using suture material and also that conjunctiva could be closed with Tisseel remnant.