Securing extraocular muscles in strabismus surgery: biomechanical analysis of muscle imbrication and knot tying technique

An experimental study was performed to quantitatively evaluate the tensile strength implications of two important steps in extraocular muscle surgery: muscle imbrication and knot configuration. The study was conducted in a controlled fashion using fresh ex vivo pig eyes with extraocular muscles attached and a precision digital force gauge. The study provides clinically translatable data to inform optimal surgical technique. The results suggest that imbrication of the muscle edge is most secure when the suture is looped around itself in a manner that allows it to be tightly cinched and locked and that granny knots possess similar tensile strength to square knots.