To the extent possible under law, AOP-Wiki has waived all copyright and related or neighboring rights to KE:1643
Key Event Title
Altered, Visual function
Key Event Components
Key Event Overview
AOPs Including This Key Event
|AOP Name||Role of event in AOP||Point of Contact||Author Status||OECD Status|
|retinaldehyde dehydrogenase inhibition,population decline||KeyEvent||Young Jun Kim (send email)||Under Development: Contributions and Comments Welcome||Under Development|
|TPOi retinal layer structure||KeyEvent||Lucia Vergauwen (send email)||Under development: Not open for comment. Do not cite|
|TPOi eye size||KeyEvent||Lucia Vergauwen (send email)||Under development: Not open for comment. Do not cite|
|TPOi photoreceptor patterning||KeyEvent||Lucia Vergauwen (send email)||Under development: Not open for comment. Do not cite|
|Inhibition of Fyna leading to increased mortality||KeyEvent||Vid Modic (send email)||Under development: Not open for comment. Do not cite|
Key Event Description
The decrease in visual function can have different aspects, such as loss of chromatic vision, changes in eye movements, differences in sensitivity to light, but also changes in the retinal pigment epithelium (RPE) that may be related to a decrease in visual function (Strauss, 2005). The visual system is highly variable from one species to another, and this variability is a key factor influencing animal behaviour (Corral-López et al., 2017).
Decreases in these visual functions can have a strong impact on behaviour, leading to changes in individual response and abilities in the environment, including, for example, perception of food or avoidance of predators. Variation in the visual system can also influence learning tasks when visual stimuli are used (Corral-López et al., 2017).
How It Is Measured or Detected
Studies of spatial and temporal aspects of the visual system have focused on assessments of optomotor (whole body swimming) or optokinetic (eye movement) responses. These responses are unconditioned optical and motor reactions including:
Opto Kinetic response, OKR (similar protocol for Rat/mice (Segura et al., 2018), fish (Zou et al., 2010) and humans (Kang and Wildsoet, 2016)). The OKR is a visually-mediated assay in which an individual will respond to alternating black and white stripes by exhibiting eye saccades, eye movements without coordinated body movements, in the same direction as rotating stripes. An eye saccade relies on the ability to rapidly move the eye from focusing on one external target to the next in a repeated manner (Magnuson et al., 2020). Optokinetic tracking has a robust performance and does not require training the animal, allowing for the quick assessment (and at earlier ages) of visual features such as visual acuity (VA) and contrast sensitivity (CS)11–14. However, the main disadvantage of optokinetic tracking is that it is a subjective method in which the decision about whether the animal is performing the optokinetic tracking or not is made by an experimenter (Segura et al., 2018).
Opto Motor Reponses, OMR. OMR tracks the ability of the fish to swim in the direction of a perceived motion when presented with a whole-field stimulus (Neuhauss, 2003), (Gould et al., 2017)).
Light-dark transition or vision startle response: reaction to change in light intensity (light sensitivity) (Brastrom et al., 2019)
Black-white preference test (Baumann et al., 2016)
Diverse Mobility assay including Tracking, touch-evoked escape-response assays, Swirl assays, locomotion assay, swimming activity, phototactic swimming activity assay, induced locomotor response (LLR) (Baumann et al., 2016; Gao et al., 2015; Zhao et al., 2014))
Domain of Applicability
Visual function decrease can be evaluated in wide range of species including mammals, amphibians, fish and humans. Evaluation of these visual function modification change according to the species and its environment.
Vision plays a crucial role in the early life stages of most species, as timing of eye development and establishment of functional vision is essential for perception of food or avoidance of predators for example (Carvalho et al., 2002).
Some studies have also shown a decrease in vision related to age (Brastrom et al., 2019; Martínez-Roda et al., 2016; Segura et al., 2018) including on visual acuity, visual fields, colour vision and dark adaptation, are well documented (Hennelly et al, 1998)
Sex seems not relevant for most of the visual function decreases observed in different studies.
Differences according to the sex of the individuals have however been reported concerning the basic visual capacities (e.g. color perception, Contrast sensitivity, visual Acuity, motion perception,...) but also concerning the frequency of certain diseases influencing these diminished visual functions, notably in humans (Vanston and Strother, 2017).
Baumann, L., Ros, A., Rehberger, K., Neuhauss, S.C.F., Segner, H., 2016. Thyroid disruption in zebrafish (Danio rerio) larvae: Different molecular response patterns lead to impaired eye development and visual functions. Aquat. Toxicol. 172, 44–55. https://doi.org/10.1016/j.aquatox.2015.12.015
Brastrom, L.K., Scott, C.A., Dawson, D. V., Slusarski, D.C., 2019. A High-Throughput Assay for Congenital and Age-Related Eye Diseases in Zebrafish. Biomedicines 7, 28. https://doi.org/10.3390/biomedicines7020028
Carvalho, P.S.M., Noltie, D.B., Tillitt, D.E., 2002. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish. Anim. Behav. 64, 1–10. https://doi.org/10.1006/anbe.2002.3028
Corral-López, A., Garate-Olaizola, M., Buechel, S.D., Kolm, N., Kotrschal, A., 2017. On the role of body size, brain size, and eye size in visual acuity. Behav. Ecol. Sociobiol. 71. https://doi.org/10.1007/s00265-017-2408-z
Gao, D., Wu, M., Wang, C., Wang, Y., Zuo, Z., 2015. Chronic exposure to low benzo[a]pyrene level causes neurodegenerative disease-like syndromes in zebrafish (Danio rerio). Aquat. Toxicol.