Experimental knotless scleral fixation with expanded polytetrafluoroethylene (ePTFE): dynamics of anchoring strength in the early postoperative period

To investigate short-term scleral response to expanded polytetrafluoroethylene (ePTFE) sutures using the dynamics of its mechanical stabilization in an animal model.

Ten rabbits underwent unilateral lens extraction followed by implantation of two knotless scleral fixation techniques using ePTFE (Gore-Tex CV-8): Z-suture and chain-of-knots. Both techniques were implanted in each eye. At postoperative days 1, 5, 10, 20, and 30, two rabbits were analyzed per time point (n = 10), each contributing one independent dynamometric measurement per technique. The tensile force required to disinsert the implanted material from the sclera was quantified using a dynamometer.

Dynamometric evaluation of tensile force of the Z-suture ranged from 0.12 to 0.32 N, whereas the chain-of-knots scleral fixation ranged from 0.07 to 0.27 N. Both techniques showed an increase in the force required to disinsert fibers from the sclera in the early postoperative period.

In this rabbit model, knotless ePTFE scleral fixation demonstrated increasing early mechanical stabilization. The differences between the two fixation techniques may be caused by a combination of mechanical factors and tissue adaptation, although these findings remain exploratory. Both techniques may provide sufficient early fixation strength in an experimental setting and support further preclinical and clinical evaluation.