Anterior Lamina Cribrosa Surface Position in Idiopathic Intracranial Hypertension and Glaucoma

Abstract

Purpose To compare the anterior lamina cribrosa (LC) surface position in patients with idiopathic intracranial hypertension (IIH), primary open-angle glaucoma (high-tension glaucoma [HTG] and normal-tension glaucoma [NTG]), and healthy controls using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Methods This was a retrospective, cross-sectional observational study of 11 eyes with IIH, 20 eyes with HTG, 20 eyes with NTG, and 37 control eyes. Serial horizontal B-scans of the optic nerve head were obtained using EDI-OCT. The LC depth, defined as the distance from the Bruch membrane opening plane to the anterior LC surface, was manually measured on selected B-scans covering the central three-quarters of the optic nerve head in each eye. Results Mean LC depth in patients with IIH (325.2 ± 92.1 µm) was significantly (p<0.01) decreased compared to control subjects (387.8 ± 53.9 µm). In HTG, the mean LC depth (493.0 ± 115.2 µm) was significantly increased compared to NTG (376.6 ± 27.1 µm, p<0.05) and control subjects (332.7 ± 53.1 µm, p<0.001). The trans-LC pressure difference (TLPD) (intraocular pressure − cerebrospinal fluid pressure) was positively correlated with the LC depth (r = 0.96, p<0.001) and inversely correlated with visual field perimetric mean deviation in patients with IIH (r = -0.88, p<0.001). Conclusions The LC is positioned anteriorly in patients with IIH and posteriorly in glaucomatous eyes compared to normal controls. The positional changes of the LC could be a result of the TLPD between the intraocular and intracranial pressure compartments.