We described a method for measuring the in vivo tensile strength of the muscle-scleral junction in rabbits. Data obtained on the reattachment time of extraocular muscles after recession and resection operations indicate the rate of healing is similar for both operations. Adequate wound healing is present by the 5th day after surgery, and sutures are probably unnecessary after 8 to 9 days. An ideal suture for strabismus surgery would be one that retains its strength during the first 8 to 9 days following surgery, then undergoes rapid absorption.

Invitro experiments with strips of pregnant rat uterus, normal estrogen-primed rat uterus and duodenum showed that cyproheptadine HCl (Periactin®), a serotonin antagonist, inhibits the intensity of spontaneous contractions of these muscle strips. The degree of inhibition depends upon the concentration of cyproheptadine. Contraction frequency was also reduced in these smooth muscles, the basic tonus not being affected. Addition of serotonin (5-HT) to the water bath increases the intensity of muscle contractions. Cyproheptadine inhibits this increase at smaller doses than those required for inhibiting spontaneous contractions. Whereas cyproheptadine does not inhibit completely the pace-maker rhythm of the muscle cells, it suppresses the amplitude of their contractions.

From our experimental studies it appears Dexon satisfies more of the criteria for an ideal suture for strabismus surgery than plain catgut for the following reasons. Its handling, tying, and knot-holding (if tighthened firmly) qualities are excellent. Tissue reaction is minimal. It seems to be non-antigenic. Of paramount importance. Dexon's tensile strength is high initially and it retains its strength through the critical period of muscle-scleral wound healing, then dissolves in a rapid uniform manner.