Evaluation of Schlemm Canal Parameters Using Swept-Source Optical Coherence Tomography in Eyes That Underwent Keratoplasty.

Abstract

In this study, we aimed to evaluate Schlemm canal parameters using anterior segment swept-source optical coherence tomography in eyes that underwent keratoplasty and compare them with keratoconus and healthy control groups. The study included 32 patients who underwent penetrating keratoplasty or deep anterior lamellar keratoplasty once due to keratoconus and age-matched and sex-matched 20 keratoconus patients and 30 healthy controls. In all the patients, a single horizontal image centered on the central cornea was obtained from the nasal and temporal quadrants with low-intensity scanning to visualize Schlemm canal. There was no statistically significant difference between the groups for age and gender ( P ˃0.05). In the keratoplasty group, the area and diameter of Schlemm canal were 2.266±1.141μm 2 and 160.77±65.08 μm, respectively, in the nasal quadrant and 2.623±1.277 μm 2 and 158.81±68.05 μm, respectively in the temporal quadrant, which were statistically significantly lower compared with other groups ( P <0.001 for all). There was no significant difference between the penetrating and deep anterior lamellar keratoplasty subgroups for Schlemm canal parameters. This is the first study to report anterior segment optical coherence tomography after surgery shows SC parameters that are, on average, less than age-matched and keratoconus controls.