Electrooculography: Difference between revisions

Latest revision as of 11:36, 15 February 2025

Electrooculography[edit]

Electrooculography (EOG) is a technique for measuring the cornea-retina standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram. EOG is used to assess the function of the retina and the ocular system, and it is also employed in the study of eye movements.

Principle[edit]

The principle of electrooculography is based on the fact that the eye acts as a dipole in which the anterior pole (cornea) is positive and the posterior pole (retina) is negative. When the eyes move, the potential between electrodes placed around the eyes changes, allowing the measurement of eye movement.

Applications[edit]

Clinical Applications[edit]

Electrooculography is used clinically to assess the function of the retina, particularly in conditions such as retinitis pigmentosa and Best's disease. It is also used to evaluate the vestibulo-ocular reflex and in the diagnosis of nystagmus.

Research Applications[edit]

In research, EOG is used to study saccades, smooth pursuit, and other types of eye movements. It is also used in sleep studies to monitor REM sleep, as shown in the diagram.

Procedure[edit]

The procedure involves placing electrodes around the eyes. Typically, electrodes are placed on the skin at the outer canthi of the eyes and above and below the eyes. The patient is asked to perform specific eye movements, and the resulting changes in potential are recorded.

Advantages and Limitations[edit]

Advantages[edit]

Non-invasive and relatively easy to perform.
Can be used to monitor eye movements in various settings, including sleep studies.

Limitations[edit]

Less precise than other methods such as infrared oculography or video-based eye tracking.
Susceptible to noise from muscle activity and electrical interference.

Related pages[edit]

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-'''Electrooculography''' ('''EOG''') is a technique used to measure the corneo-retinal standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram. Primary applications are in ophthalmological diagnosis and in recording eye movements. Unlike the [[electroretinography]] (ERG), the EOG does not measure response to individual visual stimuli.
+== Electrooculography ==
+[[File:Sleep_Stage_REM.png|thumb|right|Diagram showing eye movements during REM sleep]]
+'''Electrooculography''' (EOG) is a technique for measuring the [[cornea]]-[[retina]] standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram. EOG is used to assess the function of the [[retina]] and the [[ocular]] system, and it is also employed in the study of [[eye movement]]s.
 == Principle ==
-The eye acts as a dipole in which the anterior pole is positive and the posterior pole is negative. EOG measures the potential difference between the front and the back of the human eye. It is usually recorded using electrodes placed on the skin around the eye, which detect changes in the electrical potential as the eye moves. This change in potential provides a measure of eye movement.
+The principle of electrooculography is based on the fact that the eye acts as a dipole in which the anterior pole (cornea) is positive and the posterior pole (retina) is negative. When the eyes move, the potential between electrodes placed around the eyes changes, allowing the measurement of eye movement.
+== Applications ==
+=== Clinical Applications ===
+Electrooculography is used clinically to assess the function of the [[retina]], particularly in conditions such as [[retinitis pigmentosa]] and [[Best's disease]]. It is also used to evaluate the [[vestibulo-ocular reflex]] and in the diagnosis of [[nystagmus]].
+=== Research Applications ===
+In research, EOG is used to study [[saccades]], [[smooth pursuit]], and other types of eye movements. It is also used in [[sleep studies]] to monitor [[rapid eye movement sleep|REM sleep]], as shown in the diagram.
 == Procedure ==
-The patient is asked to sit with their head steady, and to move their eyes in a specific pattern. This can include looking straight ahead, looking to the left or right, or following a light as it moves across the patient's field of vision. The electrodes detect the movement of the eye, and this information is recorded and can be analyzed to help diagnose a range of conditions.
+The procedure involves placing electrodes around the eyes. Typically, electrodes are placed on the skin at the outer canthi of the eyes and above and below the eyes. The patient is asked to perform specific eye movements, and the resulting changes in potential are recorded.
+== Advantages and Limitations ==
+=== Advantages ===
-== Applications ==
+* Non-invasive and relatively easy to perform.
+* Can be used to monitor eye movements in various settings, including sleep studies.
-EOG is used in the investigation and diagnosis of some diseases such as [[Parkinson's disease]], [[brain stem death]] and [[multiple sclerosis]]. It is also used in research into sleep disorders, where it is used to measure rapid eye movement (REM) during sleep. In addition, it can be used to detect eye movement in situations where it may not be observable otherwise, such as in the study of reading.
+=== Limitations ===
-== Limitations ==
+* Less precise than other methods such as [[infrared oculography]] or [[video-based eye tracking]].
+* Susceptible to noise from [[muscle]] activity and [[electrical interference]].
-EOG is not very accurate for tracking eye position, which is better achieved with infrared eye trackers. The EOG is most useful for measuring saccadic eye movement, and is not very reliable for slow eye movement or where the eye is stationary.
+== Related pages ==
-== See also ==
 * [[Electroencephalography]]
 * [[Electromyography]]
-* [[Electroretinography]]
+* [[Polysomnography]]
+* [[Eye movement]]
-== References ==
+[[Category:Electrophysiology]]
-{{reflist}}
-[[Category:Medical tests]]
 [[Category:Ophthalmology]]
-[[Category:Neurophysiology]]
-[[Category:Electrophysiology]]
-{{medicine-stub}}