Anterior segment optical coherence tomography assessment of Schlemm’s canal before and after Descemet membrane endothelial keratoplasty: A retrospective observational study

Purpose: This study aimed to evaluate Schlemm’s canal (SC) parameters using anterior segment optical coherence tomography (AS-OCT) in eyes undergoing Descemet membrane endothelial keratoplasty (DMEK). Design: This is a retrospective, cross-sectional, observational study. Methods: The study included 22 eyes from 22 patients with pseudophakic bullous keratopathy, with a mean age of 70 ± 11.4 years. AS-OCT (Triton) scans were performed with the patient fixating nasally; horizontal images were obtained from the temporal limbus to visualize SC. Results: A significant difference was found in visual acuity [1.9 (0.5–2.3) LogMAR vs. 0.5 (0.1–2.3) LogMAR, respectively] and central corneal thickness (CCT) [850 (630–950) µm vs. 545 (407–900) µm, respectively] before and after DMEK surgery ( P < 0.01 for both). No significant difference was observed in postoperative intraocular pressure (IOP) [12 (6–20) mmHg] compared to preoperative values [13 (6–18) mmHg] ( P = 1.00). There was a significant difference between the preoperative and postoperative SC length (SCL) values (249 µm vs. 266.5 µm, respectively; P < 0.001) as well as SC area (SCA) values (4893.5 µm² vs. 5227 µm², respectively) at the third month ( P = 0.001). Changes in CCT and IOP were not significantly correlated with changes in SCA ( P = 0.658 vs. P = 0.460) or SCL ( P = 0.435 vs. P = 0.377). Tamponade with sulfur hexafluoride (SF₆) or air did not significantly affect preoperative and postoperative SCA ( P = 0.974 vs. P = 0.821, respectively) and SCL ( P = 0.974 vs. P = 0.792, respectively). Conclusion: AS-OCT imaging revealed postoperative expansion of SC parameters following DMEK, with no detectable adverse impact attributable to the surgical procedure or SF₆ use.