Related Experiment Video
Updated: Jul 4, 2026
08:55
Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments
Published on: April 24, 2020
Mechanical environment of the optic nerve head in glaucoma
J Crawford Downs1, Michael D Roberts, Claude F Burgoyne
1Devers Eye Institute, Legacy Health System, Portland, Oregon 97232, USA. cdowns@deverseye.org
Summary
The optic nerve head (ONH) is a vulnerable area where retinal ganglion cell axons transition. Biomechanics plays a crucial role in the ONH
Area of Science:
- Ophthalmology
- Biomechanics
- Neuroscience
Background:
- The optic nerve head (ONH) is a structurally unique region supporting retinal ganglion cell axons.
- It acts as a transition zone between the high intraocular pressure (IOP) environment of the eye and the low-pressure retrobulbar space.
- The lamina cribrosa, a complex connective tissue network, provides essential structural and vascular support within the ONH.
Purpose of the Study:
- To describe the current understanding of the biomechanical environment of the optic nerve head.
- To emphasize the influence of biomechanics on glaucoma pathogenesis.
- To explore how biomechanics mediates IOP-related changes in ONH blood flow and cellular responses.
Main Methods:
- Review of existing literature on optic nerve head biomechanics.
- Analysis of the structural and functional roles of the lamina cribrosa.
- Investigation of the vascular supply within the ONH and its relation to biomechanical forces.
Main Results:
- The ONH is a biomechanically sensitive weak spot in the corneo-scleral envelope.
- The lamina cribrosa's intricate structure is vital for protecting axons under pressure.
- Intrascleral and intralaminar vasculature within load-bearing connective tissue is uniquely integrated.
- Biomechanical factors are believed to influence IOP-related blood flow reductions and cellular responses in glaucoma.
Conclusions:
- Biomechanics is a critical factor in maintaining ONH integrity and function.
- Understanding ONH biomechanics is essential for elucidating glaucoma mechanisms.
- Biomechanical forces likely mediate key pathological pathways in glaucoma, affecting both structure and vascular health.
Related Concept Videos
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:27Open Angle Glaucoma: Treatment
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...