{"id":6017,"date":"2026-01-23T14:20:28","date_gmt":"2026-01-23T11:20:28","guid":{"rendered":"https:\/\/lvo.hosting.dgu.uoc.gr\/?page_id=6017"},"modified":"2026-01-29T14:20:15","modified_gmt":"2026-01-29T11:20:15","slug":"visual-electrodiagnostic-tests","status":"publish","type":"page","link":"https:\/\/lvo.hosting.dgu.uoc.gr\/en\/for-patients\/visual-electrodiagnostic-tests\/","title":{"rendered":"Visual electrodiagnostic tests"},"content":{"rendered":"\t\t
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Electrophysiology of Vision\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Sometimes it is difficult to find out the exact point of damage in the pathway of vision or to determine how well babies can see. Each image we see is interpretated to an electrical sign. It is possible to detect this elecrical response each time a light flashes or a stimulus moves or suddenly appears. This responce comes either from retina, the light-detecting part of the eye (electro-retinogram, ERG) or the region of the brain that is responsible for vision (visual evoked potentials, VEP). We have the ability to detect all reaction that come from different stimuli through electods that are placed at the back of the head for VEP and next to the eyelids for the ERG.<\/p>

These special tests may help us in the diagnosis of a dysfunction in the optical pathway, at the level of retina, optic nerve or brain cells. They also provide information about the right perception of shapes.\u00a0These examinations are held daily in our Institute by trained staff, they are not at all invasive and they are completely safe for babies and infants. Local anaesthesia is not necessary.<\/strong>\u00a0In the ERG exam we have to use eye drops for the mydriasis of the pupil. In case that a child is examined, the parental support and cooperation is very important to make the examination convenient.<\/p>

Please do not forget to bring your glasses and eyeglasses with you!<\/p>

Further information from:<\/b><\/mark><\/p>

Department of Electrophysiology<\/h2>

The Department of Electrophysiology of the Lab of Vision and Optics provides diagnostic services of high quality, guaranteed by the use of advanced equipment such as the Ganzfelt dome (Colordome, Diagnosys LLC<\/a>), a high resolution screen, a differential signal amplifier (CED 1902 amplifier<\/a>), a timing unit (CED Micro 1401<\/a>), a photometer and a scpectroradiometer.<\/p>

All examinations are prepared in accordance with the standards of the International Society of Clinical Electro-Vision (ISCEV<\/a>) by trained personel. In all tests recording electrodes are used and there is no need of any kind of anaesthesia.<\/p>

The electrophysiological tests provide us with information on the fuction of the optical path from the eye to our brain via the optic nerve. Depending on which stage of the process of the optical sign they monitor, we divide them as following:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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The evoked by diffuse light electroretinogram (flash ERG)<\/h6>\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t
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\u03a4his is the main test for diagnosing diseases of the retina, such as retinitis pigmentosa, retinal dystrophies and any kind of macula degeneration (ie cone dystrophies, Staargardt disease, Leber disease etc). Using this test we can test the integrity of the two kinds of photoreceptors -cones and rodes- separately and at the same time the separation of different types of cones (S cones) is feasible.<\/p>\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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The electroretinogram evoked by stimulation (pattern ERG)<\/h6>\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t
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\u03a4he pERG reflects activity in the gagglion layer and it is the examination of choice for checking the integrity of central vision, ie the functionality of the macula. The visual stimuli that are typically used consist of a “chessboard” oe black and white squares of alternating form. Measurments are performed separately for each eye.<\/p>\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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The electrooculargram<\/h6>\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t
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\u0399t is used to check the integrity of the melachroun epithelium. It is the examination of choice for patients that suffer from the disease of Best.<\/p>\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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The Visual Evoked Potentials (VEP)<\/h6>\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t
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\u03a4his test records group responses of ganglion cells in the pre-cortical visual tract and brain neurons of the occipital lobe. Therefore VEP are used in the diagnosis of diseases of the optic nerve. For the examination we use the same pattern as in pERG.\u00a0<\/p>\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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To make an appointment, please contact the Department Secretariat.<\/h4>\n\t\t\t\n\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\tPhone number<\/span>\n\t\t\t\t\t\t\t\t+30 2810 371800<\/span>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Electrophysiology of Vision Sometimes it is difficult to find out the exact point of damage in the pathway of vision or to determine how well babies can see. Each image we see is interpretated to an electrical sign. It is possible to detect this elecrical response each time a light flashes or a stimulus moves or suddenly appears. This responce comes either from retina, the light-detecting part of the eye (electro-retinogram, ERG) or the region of the brain that is responsible for vision (visual evoked potentials, VEP). We have the ability to detect all reaction that come from different stimuli through electods that are placed at the back of the head for VEP and next to the eyelids for the ERG. These special tests may help us in the diagnosis of a dysfunction in the optical pathway, at the level of retina, optic nerve or brain cells. They also provide information about the right perception of shapes.\u00a0These examinations are held daily in our Institute by trained staff, they are not at all invasive and they are completely safe for babies and infants. Local anaesthesia is not necessary.\u00a0In the ERG exam we have to use eye drops for the mydriasis of the pupil. In case that a child is examined, the parental support and cooperation is very important to make the examination convenient. Please do not forget to bring your glasses and eyeglasses with you! Further information from: Department of Electrophysiology The Department of Electrophysiology of the Lab of Vision and Optics provides diagnostic services of high quality, guaranteed by the use of advanced equipment such as the Ganzfelt dome (Colordome, Diagnosys LLC), a high resolution screen, a differential signal amplifier (CED 1902 amplifier), a timing unit (CED Micro 1401), a photometer and a scpectroradiometer. All examinations are prepared in accordance with the standards of the International Society of Clinical Electro-Vision (ISCEV) by trained personel. In all tests recording electrodes are used and there is no need of any kind of anaesthesia. The electrophysiological tests provide us with information on the fuction of the optical path from the eye to our brain via the optic nerve. Depending on which stage of the process of the optical sign they monitor, we divide them as following: The evoked by diffuse light electroretinogram (flash ERG) \u03a4his is the main test for diagnosing diseases of the retina, such as retinitis pigmentosa, retinal dystrophies and any kind of macula degeneration (ie cone dystrophies, Staargardt disease, Leber disease etc). Using this test we can test the integrity of the two kinds of photoreceptors -cones and rodes- separately and at the same time the separation of different types of cones (S cones) is feasible. The electroretinogram evoked by stimulation (pattern ERG) \u03a4he pERG reflects activity in the gagglion layer and it is the examination of choice for checking the integrity of central vision, ie the functionality of the macula. The visual stimuli that are typically used consist of a “chessboard” oe black and white squares of alternating form. Measurments are performed separately for each eye. The electrooculargram \u0399t is used to check the integrity of the melachroun epithelium. It is the examination of choice for patients that suffer from the disease of Best. The Visual Evoked Potentials (VEP) \u03a4his test records group responses of ganglion cells in the pre-cortical visual tract and brain neurons of the occipital lobe. Therefore VEP are used in the diagnosis of diseases of the optic nerve. For the examination we use the same pattern as in pERG.\u00a0 To make an appointment, please contact the Department Secretariat. Phone number +30 2810 371800<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":5974,"menu_order":7,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-6017","page","type-page","status-publish","hentry","post-no-thumbnail"],"_links":{"self":[{"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/pages\/6017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/comments?post=6017"}],"version-history":[{"count":11,"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/pages\/6017\/revisions"}],"predecessor-version":[{"id":6440,"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/pages\/6017\/revisions\/6440"}],"up":[{"embeddable":true,"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/pages\/5974"}],"wp:attachment":[{"href":"https:\/\/lvo.hosting.dgu.uoc.gr\/wp-json\/wp\/v2\/media?parent=6017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}