Effect of Saline Conditions on the Tensile Strength of Ophthalmic Sutures

Background and Objective: The purpose of this study was to compare the tensile strength of sutures commonly used for ophthalmic surgery and the role of physiologically balanced saline comparable to the ocular environment to material failure. Materials and Methods: Ophthalmic sutures (9-0 and 10-0 nylon, 7-0 and 8-0 polyglactin 910, and 10-0 polypropylene) were tested using a tensiometer. Wet conditions were defined by soaking the suture in balanced salt solution for 24 hours or 7 days prior to testing. Results: The 9-0 nylon was approximately 30% stronger than 10-0 nylon ( P < .01), whereas 7-0 polyglactin was 60% and 85% stronger than 8-0 polyglactin under dry and 24 hours of wet conditions ( P = .0014 and .004), respectively. There was no difference in tensile strength between 10-0 nylon and polypropylene sutures. The 8-0 polyglactin suture lost 11% of tensile strength after 7 days of saline exposure. Conclusion: The relative difference of suture strength between the difference gauge sutures is not a simple relationship to differences in the diameter. Tensile strength was not affected by saline conditions for the nylon, polypropylene, and 7-0 polyglactin sutures. The 8-0 polyglactin suture had a decrease in tensile strength after 7 days of exposure to saline. Surgeons should be aware of this limitation with 8-0 polyglactin.