The present disclosure provides a system and method for cutting a flap in laser ophthalmic surgery using polarization sensitive optical coherence tomography (PS-OCT). The system includes a PS-OCT system, a femtosecond laser, control device, and processor. The PS-OCT system includes a PS-OCT source, a polarization component, a reference reflector, a beam splitter, a wave plate, and a detector. The processor receives data relating to an interference pattern of a reflected PS-OCT beam, received at the detector, determines a relative fiber orientation of the sample, determines whether a photodisruption pattern generated by the femtosecond laser to cut the flap should be adjusted horizontally or vertically, based on the relative fiber orientation, and may generate a control signal to adjust the photodisruption pattern generated by the femtosecond laser. The disclosure further provides a method for cutting a flap on an eye using PS-OCT.