Changes in choroidal thickness after intraocular pressure reduction following trabeculectomy

Abstract

PurposeTo evaluate changes of choroidal thickness (CT) after an acute reduction in intraocular pressure (IOP) following trabeculectomy.MethodsSubfoveal 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.ResultsThe 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).ConclusionsThe 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.

Lamina Cribrosa Moves Anteriorly After Trabeculectomy in Myopic Eyes

“…Although we measured LC depth from the level of the BMO, we also measured choroidal thickness before and after surgery to overcome the limitation of this method. Consistent with previous observations, [30][31][32] we found that the choroid was thicker after than before surgery. Thickening of the choroid increases the distance between the BMO and the anterior LC surface, resulting in an overestimation of LC depth.…”

Simultaneous evaluation of the lamina cribosa position and choroidal thickness changes following deep sclerectomy

“…Significant changes in LC position [1][2][3][4] and CT have been reported [17][18][19][20][21][22] after filtering surgery. CT can influence the LCD assessment as measured from BMO reference line, [6][7][8][9] and it is a dynamic parameter depending on several factors including IOP fluctuations.…”

“…For detecting CT changes, we estimated a sample size of 36 eyes to reach an error alpha = 0.05 and a statistical power of 80%. 19 One-sample Kolmogorov-Smirnov test was used to verify normal distribution. The quantitative information was expressed as mean and standard deviation.…”

“…[9][10][11][12][13][14][15][16] In eyes with a thick peripapillary choroid, the LCD would be overestimated and, in contrast, it would be underestimated in eyes with a thin choroid. That point is relevant because a significant choroidal thickening has been reported after trabeculectomy using SD OCT with EDI [17][18][19][20][21] and swept-source (SS) OCT. 22 All these reported CT measurements were made manually.…”

The Impact of Choroidal Swelling on Optic Nerve Head Deformation

“…6,12 Interestingly, clinical evidence suggests that IOP and choroidal volume themselves may be linked. 45,46 A reduction of IOP via trabeculectomy or deep sclerectomy has been shown to cause a subsequent change in choroidal thickness. Thus, studies aimed at understanding the interaction of IOP and choroid volume and their combined influence on ONH biomechanics will be critical in the future.…”