Lamina cribrosa displacement after trabeculectomy in pseudoexfoliation and primary open angle glaucoma

Abstract

PurposeTo compare the changes in lamina cribrosa depth between eyes with pseudoexfoliation glaucoma (PEXG) and primary open angle glaucoma (POAG) following trabeculectomy.MethodsThe prospective study included 37 glaucomatous eyes (23 PEXG and 14 POAG). The lamina cribrosa depth was measured using enhanced depth imaging spectral domain optical coherence tomography before trabeculectomy and three months after the surgery. The postoperative displacement of the lamina cribrosa (LCD) was compared between the PEXG and POAG groups. The relationship between LCD and intraocular pressure (IOP) reduction was analysed.ResultsThere was a significant reduction in the mean (±SD) IOP in PEXG and POAG eyes following the trabeculectomy (14.2 ± 7.2 mmHg, p < 0.001, 14.4 ± 7.5 mmHg, p < 0.001; respectively). In total, the median (IQR) depth of the lamina cribrosa decreased from 469.4 (209.3) μm at baseline to 443.7 (145.5) μm three months after the surgery (p < 0.001). No significant difference in median (IQR) postoperative lamina cribrosa displacement between the PEX and POAG patients was found (42.1 (50.8) μm and 22.8 (53.9) μm, respectively; p = 0.186). The anterior displacement of lamina cribrosa after trabeculectomy did correlate significantly neither with the baseline IOP nor with the IOP reduction in the examined groups.ConclusionsIn glaucomatous eyes the anterior displacement of the lamina cribrosa occurred after the IOP reduction following trabeculectomy. However, no differences in the decrease of the lamina cribrosa depth were found between the pseudoexfoliation glaucoma and primary open angle glaucoma patients. The association between the lamina cribrosa displacement and IOP reduction was not significant.