Optic nerve cupping and lamina cribrosa sclerae depth as a resultant of translaminar pressure difference

Abstract

PurposeThe aim of the research was to evaluate correlation between translaminar pressure difference (TLPD) and optic nerve head (ONH) morphology parameters: lamina cribrosa sclerae depth (LCD) and optic nerve cupping (ONC).MethodsStudy included 42 eyes of 25 patients qualified to undergo lumbar puncture (LP) due to neurological circumstances. LCD, ONC and intraocular pressure (IOP) were measured 1–3 h prior to LP during ophthalmic examination. IOP was measured using Goldmann applanation tonometry. ONH morphology parameters: LCD and ONC were assessed using enhanced depth imaging optical coherence tomography (EDI‐OCT). CSFP was measured during lumbar puncture. TLPD was calculated as a difference between IOP (mmHg) and CSFP (mmHg).Results20 female eyes and 22 male eyes were included in the study. Mean age of female subjects was 44.1 ± 18.00 while the mean age of male subjects was 54.73 ± 13.57. LCD was revealed to be significantly deeper in male population (mean 365.83 μm vs. 296.07 μm). Statistical analysis revealed a strong positive correlation between LCD and TLPD (p < 0.0001, R = 0.78) and between LCD and ONC (p < 0.0001, R = 0.71).ConclusionsThere is a strong positive correlation between TLPD and ONH morphology parameters. LCD and ONC should therefore be viewed as a resultant of two pressure compartments: IOP and CSFP. Intraocular pressure is since many years a confirmed modifiable risk factor for development and progression of glaucomatous neuropathy. CSFP was also proved to be significantly lower among primary open angle glaucoma subjects. In future LCD and ONC as a resultant of TLPD could therefore play a role in assessing the risk of glaucomatous neuropathy progression. According to significant correlation between TLPD and ONH morphology parameters, combined LCD and IOP measurement could moreover play a role as a non‐invasive CSFP assessment tool.