Changes in Corneal Biomechanical Properties After Descemet Stripping Automated Endothelial Keratoplasty for Pseudophakic Bullous Keratopathy

Abstract

To compare corneal biomechanical properties and intraocular pressure (IOP) in eyes with pseudophakic bullous keratopathy (PBK) before and after Descemet stripping automated endothelial keratoplasty (DSAEK). This prospective nonrandomized intrasubject comparative study was conducted on 44 eyes of 22 patients with the diagnosis of PBK who underwent DSAEK in one eye. IOP was measured by Goldmann applanation tonometer, and central corneal thickness was measured by ultrasound pachymetry. The ocular response analyzer was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-related IOP, and cornea-compensated IOP. The same measurements were performed in the normal fellow eyes which served as controls. All measurements were performed preoperatively and 6 months postoperatively. The mean patient age was 67 ± 14 years. Mean preoperative CH and CRF values in the DSAEK group were 5.77 ± 2.94 and 6.39 ± 2.72 mm Hg, respectively, which were significantly lower than those measured in the control group (8.2 ± 2.47 and 8.43 ± 2.49 mm Hg, respectively, P = 0.001 for both comparisons). Postoperatively, CH and CRF demonstrated a significant increase (7.09 ± 3.68 mm Hg, P = 0.05 and 8.21 ± 3.84 mm Hg, P = 0.03, respectively) in operated eyes approaching the normal values measured in the control eyes. Corneal biomechanical parameters were significantly lower in PBK eyes than in the normal fellow eyes. These metrics significantly increased after DSAEK and reached values measured in the normal fellow eyes.