Changes in lamina cribrosa and prelaminar tissue after deep sclerectomy

Abstract

Aim To determine the response of the lamina cribrosa (LC) and prelaminar tissue to a reduction of intraocular pressure (IOP) after nonpenetrating deep sclerectomy (NPDS) using enhanced depth imaging (EDI) spectral domain optical coherence tomography (SD-OCT). Methods A total of 28 eyes from 28 patients presenting with primary open angle glaucoma who underwent NPDS were studied. SD-OCT scans using EDI technology were obtained before surgery and 1 week, 1 month, and 3 months postoperatively. The OCT device was set to image a 15 Â 101 vertical rectangle centred on the optic disc. The scan closest to the optic nerve head (ONH) centre was selected for analysis. The vertical distances from three equidistant points on the reference line (Bruch's membrane opening) to the anterior prelaminar tissue surface and the anterior and posterior surfaces of the LC were measured. Results The IOP decreased from 18.7 ± 4.3 to 9.1±4.0 at the first week, 11.4±3.7 at 1 month, and 13.1±3.6 mm Hg at 3 months postoperatively (Po0.001). There was a significant reduction of the ONH cupping at 1 week (22.3%, Po0.001), 1 month (13.7%, Po0.001), and 3 months (9.8%, P ¼ 0.001) after surgery. Anterior displacement of the LC was slight but statistically significant at 1 week (4.5%, P ¼ 0.003), 1 month (3.8%, P ¼ 0.014), and 3 months postoperatively (3.3%, P ¼ 0.010). IOP reduction was significantly correlated with a reduction of ONH cupping and anterior displacement of LC at the first week and first month (Po0.05). Conclusions Cupping reversal after NPDS is mainly due to changes in prelaminar tissue thickness, whereas the LC changes in position are less pronounced.

Bruch's membrane opening changes and lamina cribrosa displacement in non-arteritic anterior ischaemic optic neuropathy

“…PT thickening has been implied in the cupping reversal phenomenon observed after intraocular pressure (IOP) reduction in patients with glaucoma 15 16. In a NAION context, optic fibre swelling is the most plausible explanation, reinforced by the fact that average PTT and RNFL thickness significantly correlated at onset and in corresponding points of measurements (table 3).…”

“…All subjects underwent peripapillary OCT (RNFL (retinal nerve fibre layer)-N axonal protocol),8 and ONH scanning using the EDI technique16 with Spectralis OCT (Heidelberg Engineering, Inc, Heidelberg, Germany) at onset and at 2 and 6 months after the acute episode.…”

Intra- and Inter-Rater Agreement of Anterior Lamina Cribrosa Depth Measurements Using Enhanced-Depth Imaging Optical Coherence Tomography

“…Numerous studies have focused on the intraocular pressure-induced ALCD displacement as an important factor of glaucomatous neuropathy [5,16,18,20,21] . For instance, posterior LC displacement and increased depth of the anterior LC have been described and may constitute the primary event in glaucoma [2,4,8,9,16,22] .…”

“…ALCD is being measured more often, is an emerging area of study and may become a widely accepted procedure in clinical practice and research [16,20] . In contrast to retinal imaging, automated ALCD segmentation algorithm software is not available.…”

Prelamina and Lamina Cribrosa in Glaucoma Patients With Unilateral Visual Field Loss

“…30,32,33 The results of a previous in vitro study showed that elevated IOP can cause the LC to deflect posteriorly, 34 leading to its curvature change. 9 He et al 24 observed longitudinal change of ONH in an experimental monkey model, demonstrating that ONH surface change precedes the changes of RNFL, scanning laser perimetry, and multifocal electroretinography.…”