Author/Editor		Tekavčič-Pompe, Manca; Brecelj, Jelka; Stirn-Kranjc, Branka
Title		Kako testirati barvni vid pri otroku
Translated title		Certification of colour vision in child
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 73, št. 5
Publication year		2004
Volume		str. 451-4
Language		slo
Abstract		Background. Studies have shown that chromatic information of visual stimulus is conducted and analysed in two major pathways, parvocellular (also named redgreen pathway) and koniocellular (also named blue yellow pathway). They both start in the retinal photoreceptors (cones) and finish in visual cortex. Colour vision can be tested in several different ways. Subjective psychophysical tests include Ishihara, Farnsworth-Munsell tests and anomaloscope, whereas objective tests include chromatic electroretinography (ERG), which can test cone function and chromatic visual evoked potentials (VEP), which can test parvocellular and koniocellular pathway function. Aim. To introduce a new method by choosing the optimal stimulus, which stimulates selectively parvocellular and koniocellular pathway. To show the stimulus and the signal in a child with normal colour vision and in a child with green deficiency (deuteranomalia). Methods and results. Isoluminant redgreen (blueyellow) stimulus was introduced. The stimulus was 7 deg large, round, composed of horizontal gratings. Spatial frequency was 2 c/deg, frequency of stimulation 1 Hz, onset: offset was 300: 700 ms. Two children are presented, a girl with normal colour vision and a boy with deuteranomalia. Characteristic N1 negative wave was significant in girl after red-green and blue yellow stimulation, whereas in boy with deuteranomalia N1 was absent after blue yellow and evident after redgreen stimulation. Conclusions. Chromatic VEP, as an objective colour vision testing method, could have an important role in testing children, therefore its study is important.
Summary		Izhodišča. Raziskave so pokazale, da se barvni vidni dražljaj prevaja in analizira po parvocelularni in koniocelularni poti od fotoreceptorjev (čepnic) do vidne skorje. V parvocelularni poti se obdelujejo informacije o rdeče-zelenem, v koniocelularni poti pa o rumeno-modrem delu barvnega spektra. Barvni vid lahko testiramo s pomočjo številnih subjektivnih, psihofizičnih testov, kot so Ishihara, Farnswoth-Munsell in anomaloskop, ter objektivnih testov, kot so barvna elektroretinografija (ERG), ki testira delovanje čepnic in barvni vidni evocirani potenciali (VEP), ki testirajo parvocelularno in koniocelularno pot. Namen. Vpeljava metode z iskanjem dražljaja, ki bi bil klinično uporaben pri testiranju barvnega vida otrok. Prikaz dražljaja in registriranega signala parvocelularne in koniocelularne poti pri otroku z normalnim barvnim vidom ter pri otroku s prirojeno slabšim zaznavanjem zelene barve (devteranomalija). Metoda in rezultati. Uveden je bil izoluminantni rdeče-zeleni/rumeno-modri 7 stopinj velik, okrogel dražljaj, sestavljen iz horizontalnih črt. Prostorska frekvenca je bila 2 c/st, frekvenca draženja 1 Hz. Dražljaj se je pojavljal in izginjal na zaslonu v razmerju 300:700 ms (onset-offset). Prikazana sta primera dveh otrok, deklice z normalnim barvnim vidom in fanta z devteranomalijo. Značilni val N1 je pri deklici dobro izražen na draženje z rdeče-zelenim in rumeno-modrim barvnim dražljajem, pri fantu pa na draženje z rdeče-zelenim dražljajem vala ne zaznamo, na draženje z rumeno-modrim dražljajem pa je val N1 izražen. Zaključki. Razvoj barvnega VEP je smiseln, saj bi kot objektivna metoda lahko igral pomembno vlogo v klinični praksi predvsem pri testiranju otrok.
Descriptors		COLOR PERCEPTION COLOR PERCEPTION TESTS EVOKED POTENTIALS, VISUAL ELECTRORETINOGRAPHY CHILD