Positional and shape changes of lamina cribrosa after trabeculectomy in pseudoexfoliative and primary open angle glaucoma

Abstract

PurposeTo evaluate positional and shape changes of anterior lamina cribrosa (LC) after trabeculectomy and compare them between eyes with pseudoexfoliative (PEXG) and primary open angle glaucoma (POAG).MethodsThe prospective study included 99 eyes (78 PEXG and 21 POAG) planned for trabeculectomy. The morphological parameters of LC and intraocular pressure (IOP) were measured pre‐ and postoperatively (1 week and 1, 3, 6 and 9 months after the surgery). LC was imaged using enhanced depth imaging spectral domain optical coherence tomography. The mean and sectoral LC depth (LCD), global shape index (GSI), curvedness and curvatures in main meridians were calculated using Morphology 1.0 software. LC parameters were compared across the follow‐up visits and in‐between PEXG and POAG groups.ResultsThe mean IOP reduced in PEXG and POAG eyes after the trabeculectomy at all follow‐up visits (p < 0.001). There was a decrease in mean and sectoral LCD (p < 0.001), curvedness (p < 0.001), nasal‐temporal (N‐T) and superior‐inferior (S‐I) curvatures (p < 0.001, p = 0.045, respectively) during whole postoperative period. LC GSI did not change significantly postoperatively and stayed in‐between a trough and rut shape (p = 0.065). There were no differences in the changes of LC morphology between PEXG and POAG eyes (p > 0.05); however a tendency of greater reduction in LCD and curvature was observed. The decrease in LCD, N‐T and S‐I curvatures correlated positively with IOP reduction(ρ = 0.326, ρ = 0.3, ρ = 0.261, p < 0.01 after 1 week, respectively).ConclusionsTrabeculectomy induced a long term mean and sectoral anterior displacement as well as flattening of LC. However, the overall shape of LC was not affected postoperatively. Despite a potential elastinopathy of pseudoexfoliative syndrome PEXG and POAG eyes did not show differences in positional and shape behaviour of LC after the surgery.