Related Experiment Video
Updated: Mar 28, 2026
16:49
Multifocal Electroretinograms
Published on: December 4, 2011
19.0K
Local Relationship between Global-Flash Multifocal Electroretinogram Optic Nerve Head Components and Visual Field
Chan Hee Moon1, Jungwoo Han2, Young-Hoon Ohn2
1Department of Ophthalmology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul 06591, Republic of Korea.
Journal of Ophthalmology
|December 24, 2015
Summary
Glaucoma patients show reduced optic nerve head component (ONHC) amplitude in multifocal electroretinograms (mfERG). This ONHC loss strongly correlates with visual field defects, aiding glaucoma diagnosis.
Area of Science:
- Ophthalmology
- Neuroscience
- Medical Imaging
Background:
- Glaucoma is a leading cause of irreversible blindness.
- Early detection and monitoring of glaucoma are crucial for preserving vision.
- Multifocal electroretinography (mfERG) assesses retinal function, but its optic nerve head component (ONHC) relationship with visual fields needs clarification.
Purpose of the Study:
- To investigate the spatial correlation between quantified global-flash mfERG ONHC and visual field defects in glaucoma patients.
- To determine if ONHC measurements can serve as a biomarker for localized visual field loss in glaucoma.
Main Methods:
- Enrolled 39 glaucoma patients and 30 healthy controls.
- Measured and normalized ONHC amplitude from global-flash mfERG.
- Constructed ONHC deficiency maps and calculated overlap with visual field defect plots.
Main Results:
- Glaucoma patients exhibited significantly lower mean ONHC amplitudes (6.01 nV/deg²) compared to controls (10.29 nV/deg²).
- An average overlap of 71.4% was found between ONHC deficiency maps and visual field defects.
- Highest overlap (75.0%) occurred between ONHC ratios < 0.5 and total deviations < 5%.
Conclusions:
- Reduced ONHC amplitude is a characteristic finding in glaucoma patients.
- Global-flash mfERG ONHC deficiency demonstrates a strong local agreement with visual field defects, suggesting its utility in glaucoma assessment.
Related Concept Videos
01:25Glaucoma: Overview
1.6K
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...
1.6K
01:27Open Angle Glaucoma: Treatment
1.1K
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...
1.1K
01:20Anatomy of the Eyeball
11.7K
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...
11.7K
01:28Angle Closure Glaucoma: Treatment
1.6K
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...
1.6K
01:22Photoreceptors and Visual Pathways
11.0K
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,...
11.0K