Purpose: To determine the pathomechanism of increased intraocular pressure after penetrating and lamellar keratoplasty based on clinical observation and literature data. Materials and methods: Morphometric analysis of the anterior segment of the eye using spectroscopic optical coherence tomography, gonioscopy and biomicroscopy. Results: Pre- and postoperative spectroscopic optical coherence tomography scans in patients after keratoplasty reveal deformation of the peripheral cornea, narrowing of the iridocorneal angle, presence of anterior synechiae and various types of pupillary block. Conclusions: The mechanism of elevated intraocular pressure after corneal grafting is complex and depends on pre-, intra- and postoperative factors, such as anatomy changes of the iridocorneal angle, presence of anterior synechiae, as well as anterior and posterior pupillary block. Spectroscopic optical coherence tomography plays an important role in diagnosis and further treatment management.