Laboratory and clinical evaluation of a new synthetic absorbable suture for ophthalmic surgery.

A new synthetic absorbable suture, a copolymer of two simple hydroxy acids, glycolic acid and lactic acid, was evaluated in a laboratory and clinical study for its usefulness in ophthalmic surgery. The glycolactide was compared with chromic collagen of similar size. The 8/0 glycolactide showed 30% greater initial strength than 8/0 chromic collagen. Following implantation of the suture in rabbit corneas, the suture was removed at intervals and its rupture strength tested. At the end of 1 week the glycolactide retined over 90% of its initial rupture strength while chromic collagen had lost nearly 50% of its strength. After 10 days the strength of the glycolactide tended to fall rapidly and by day 21 the suture had negligible strength and began to absorb, completely disappearing by 7 weeks. Chromic collagen tended to remain in situ for many weeks although possessing negligible rupture strength. The 8/0 glycolactide was compared with 8/0 chromic collagen in suturing corneoscleral wounds of 45 consecutive patients undergoing routine cataract surgery. Handling qualities were judged and the eyes followed post-operatively to ascertain reaction to the sutures and time of final disappearance of the sutures from the eyes. The glycolactide showed no tendency to disappear from the wounds until after the fourth week. By the end of 9 weeks all the glycolactide sutures had disappeared. Chromic collagen, on the other hand, was more variable, some sutures disappearing as early as the third week while others remained in place essentially unchanged for more than 20 weeks. Neither glycolactide nor chromic collagen showed any tendency to excite reaction in the eyes and the incidence of complications was low.