Evaluation of the effect of the corneal suture removal on corneal biomechanics with Corneal visualization Scheimpflug technology (Corvis ST) after penetrating keratoplasty (PKP)

Background The cornea is a part of the anterior segment of the eye, which plays an important role in the refraction of light rays on the retina. Cornea also maintains the shape of the eyeball and constitutes a mechanical barrier, protecting the eye against external environmental factors. For the determination of corneal biomechanics, it requires application of an air puff and simultaneous imaging of the response of the tissues to the stimulus. Available methods include ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (CORVIS ST). Aim To evaluate the effect of the corneal suture removal on the corneal biomechanics with CORVIS ST after penetrating keratoplasty. Patients and methods In this prospective study, the corneal biomechanics of 30 patients who had penetrating keratoplasty were evaluated before removal of the corneal sutures at least 6 months and after 3 months of removal of sutures with CORVIS ST. Results In this study, the CORVIS ST parameters were evaluated with significant reduction of the central corneal thickness, peak distance, deformation amplitude, and Ambrosio’s relational thickness to the horizontal profile. There was significant increase in the radius of curvature and stiffness parameters at first applanation. Conclusion Good corneal biomechanics in the period after 3 months of removal of the corneal sutures and weak corneal biomechanics in the period before removal of the corneal sutures at least 6 months after penetrating keratoplasty and the measured corneal parameters have potential benefits for monitoring postoperative wound healing.