The Effects of Trabeculectomy on Ocular Pulse Amplitude in Patients with Glaucoma

OBJECTIVES: This study aimed to investigate whether trabeculectomy and its intraocular pressure (IOP)-lowering effect have an effect on ocular pulse amplitude (OPA) in glaucoma patients. METHODS: Thirty-five consecutive patients with glaucoma (70 eyes) who had undergone unilateral first-time trabeculectomy between April and November 2012 were enrolled in this retrospective study. Patients with intraoperative or postoperative complications were excluded from this study. The eye that underwent trabeculectomy was considered the study eye; the fellow eye was used as the control eye. OPA and IOP were measured by Pascal dynamic contour tonometry (DCT), IOP was measured by Goldmann applanation tonometry (GAT), and systolic and diastolic blood pressure and heart rate were measured before and one month after trabeculectomy. The change in the pre- and postoperative values was compared between the two eyes. RESULTS: The study sample included 17 male and 18 female patients with a mean age of 60.83±13.46 years. The mean preoperative GAT, DCT and OPA values in the study eyes were 24.97±8.26, 31.23±10.55 and 4.22±1.77 mmHg, respectively. One month after trabeculectomy, the GAT, DCT and OPA values were 12.83±4.35, 20.28±7.34 and 2.96±1.66 mmHg, respectively. There was a significant decrease in OPA after filtration surgery in the study eyes (p<0.001), but not in the control eyes (p>0.05). Changes in OPA were positively correlated with changes in IOP (p<0.05), and a significant association was found between OPA and IOP, and as measured by DCT (Regression coefficient = 0.093 [0.041–0.145]) and GAT (Regression coefficient = 0.093 [0.013–0.173]). CONCLUSION: There was a significant decrease in OPA in the eyes that underwent trabeculectomy, and the change in OPA after surgery was significantly different in the study eyes in comparison to the change in OPA in the control eyes. The OPA changes were strongly correlated with the IOP changes in the study eyes.