Related Experiment Video
Updated: Jun 18, 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
Optic disc diameter increases during acute elevations of intraocular pressure.
Ali Poostchi1, Tracey Wong, Kenneth C Y Chan
1Capital Eye Specialists, Wellington, New Zealand.
Investigative Ophthalmology & Visual Science
|November 13, 2009
Summary
Transiently elevating intraocular pressure (IOP) caused optic disc and linear disc measurements to increase. This optic nerve diameter change was less pronounced in glaucoma patients and greater with thicker corneas.
Area of Science:
- Ophthalmology
- Glaucoma Research
- Optic Nerve Imaging
Background:
- Intraocular pressure (IOP) is a key factor in glaucoma pathogenesis.
- Understanding optic nerve head biomechanics under elevated IOP is crucial for glaucoma diagnosis and management.
Purpose of the Study:
- To investigate changes in optic nerve diameter during transient intraocular pressure (IOP) elevation.
- To compare these changes in glaucomatous versus non-glaucomatous eyes.
Main Methods:
- Prospective experimental study involving 100 subjects (38 glaucoma, 62 controls).
- Transient IOP elevation to ~64 mm Hg for <30 seconds induced via modified LASIK suction ring.
- Optic nerve head imaging performed before and during IOP elevation.
Main Results:
- Optic disc area and linear disc measurements significantly increased during IOP elevation (3.89% and 0.96%, respectively).
- Increased central corneal thickness (CCT) correlated with greater disc area enlargement.
- Disc area increase was less in glaucoma patients and inversely proportional to baseline disc area.
Conclusions:
- Transient IOP elevation causes significant, albeit small, increases in optic disc dimensions.
- Glaucoma status and baseline disc area influence the magnitude of optic nerve head response to IOP changes.
- Corneal thickness is a factor in the optic nerve's dimensional response to elevated IOP.
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...
01:29Increased Intracranial Pressure ll: Pathophysiology
Increased intracranial pressure (ICP) refers to a potentially life-threatening rise in pressure inside the skull. This usually happens when there is a major change in the volume of brain tissue, blood, or cerebrospinal fluid (CSF) — the three components inside the skull. According to the Monro-Kellie doctrine, if the volume of one component increases, the volumes of the other components must decrease to maintain normal pressure. If this does not happen, ICP rises.The process often begins with...
01:14Increased Intracranial Pressure l: Introduction
Intracranial hypertension is a sustained elevation of intracranial pressure (ICP) above 22 mm Hg. In supine adults, normal ICP is ~7–15 mm Hg.The rigid, nonexpandable cranium contains three components—brain tissue, blood, and cerebrospinal fluid (CSF)—that total ~1,700 mL in a typical adult: 1,400 mL brain (~80%), 150 mL blood (~10%), and 150 mL CSF (~10%). According to the Monro–Kellie doctrine, total intracranial volume is effectively fixed. When one component expands, CSF and venous blood...
01:27Diabetic Retinopathy
DefinitionDiabetic retinopathy is a microvascular complication of diabetes affecting the retinal blood vessels.Risk FactorsDiabetic retinopathy is present in almost all individuals with type 1 diabetes and more than 60% of those with type 2 diabetes after two decades of disease.The risk increases with poor glycemic control, hypertension, dyslipidemia, smoking, pregnancy, and puberty.Although cataracts and glaucoma are also more frequent in people with diabetes, retinopathy remains the leading...