Changes in choroidal thickness,axial length,and ocular perfusion pressure accompanying successful glaucoma filtration surgery

Purpose

To investigate the changes in choroidal thickness (CT), axial length (AL), and ocular perfusion pressure (OPP) accompanying intraocular pressure (IOP) reduction after trabeculectomy.

Methods

Thirty-nine eyes of 39 patients with primary open-angle glaucoma uncontrolled by medical therapy were included in this prospective and interventional study. All patients underwent a fornix-based trabeculectomy. The CT was measured by enhanced depth imaging-optical coherence tomography. IOP, AL, and systolic/diastolic blood pressure were also measured, and OPP was calculated. All measurements were performed at baseline and 1 month after surgery.

Results

The mean IOP was 25.0±5.8 mm Hg at baseline and 11.7±2.6 mm Hg after trabeculectomy (P<0.001), and the mean subfoveal CT was 295±84 mm Hg at baseline and 331±82 mm Hg after trabeculectomy (P<0.001). The mean AL was 23.64±0.98 mm at baseline and 23.54±0.96 mm after trabeculectomy (P<0.001), whereas the mean OPP was 38.8±6.2 mm Hg preoperatively, and 51.1±7.3 mm Hg postoperatively (P<0.001). The change in CT negatively correlated with the change in IOP (r=−0.785, P<0.001) and AL (r=−0.693, P<0.001), whereas it positively correlated with the change in OPP (r=0.418, P=0.008).

Conclusion

These results suggest that the large IOP decrease following trabeculectomy causes choroidal thickening. In addition, CT changes are associated with IOP and AL reduction as well as OPP increase.