Changes in choroidal thickness after intraocular pressure reduction following trabeculectomy
Abstract
Purpose
To evaluate changes of choroidal thickness (CT) after an acute reduction in intraocular pressure (IOP) following trabeculectomy.
Methods
Subfoveal and peripapillary CT and IOP were measured in 40 glaucomatous eyes (40 patients) 1 day before, 1 week and 1 month after the trabeculectomy. The choroid was evaluated using spectral domain optical coherence tomography enhanced depth imaging at the fovea and 1.7 mm superior, temporal, inferior and nasal to a optic nerve head centre. Biometry was performed preoperatively.
Results
The mean IOP was significantly reduced after trabeculectomy at both follow-up visits (P < 0.001). The mean subfoveal CT (±SD) increased from 216.1 (±86.1) µm at baseline to 260.3 (±86.9) µm after one week and 243.1 (±87.1) µm after one month postoperatively (P < 0.001). The mean CT significantly increased one week after trabeculectomy at all peripapillary locations (P < 0.01), however, the thickening of choroid was significant only temporally after one month. There was positive correlation between the magnitude of change in subfoveal CT and the IOP reduction (r = 0.518, P < 0.001 for the 1-week follow-up; r = 0.290, P = 0.034 for the 1- month follow-up). The preoperative axial length correlated positively with the magnitude of thickening of subfoveal CT after one week (r = 0.451, P = 0.002).
Conclusions
The subfoveal and peripapillary CT increased with the IOP reduction following trabeculectomy, however, choroidal thickening around the optic nerve disc appeared to be short-term. The thickening of subfoveal CT was found to be related to the greater IOP reduction and longer axial length.
