Morphological Assessment of Visual Dysfunction

Abstract

The eye is an isolated unit but with a potentially high degree of sensitivity to toxic substances. The multiplicity of types of reaction to injury reflects the unique anatomical, physiological and biochemical features of the eye. The following are examples of such: The albino rat is not a good model for retinal toxicity because of problems of phototoxic retinopathy, the absence of pigment within the pigment epithelial layer and the high incidence of spontaneous retinal pathologies; The ocular toxicity of a compound cannot be anticipated from its chemical structure; Pharmacological side effects are similar between species, and are predictive for man; Mechanisms of ocular toxicity are poorly understood.

Morphological and functional evaluation of an animal model for the retinal degeneration induced byN-methyl-N-nitrosourea

“…In addition to hereditary animal models, there are various chemically induced RD models [7] which are easier to produce and in which it is easier to modulate degrees of change. One of the chemicals, N -methyl- N -nitrosourea (MNU), is a potent retinotoxin which leads to apoptotic cell death of photoreceptor cells [8-15].…”

Apoptosis of photoreceptor cells in ornithine-induced retinopathy

“…Various pharmacological agents are known to affect the RPE cells primarily [10,17] or to affect the neurosensory retina and damage the RPE secondarily [2,7,16]. When the physiological functions of the RPE are altered, the overlying retina is also affected and results in decrease of visual function.…”

Nervous System and Special Sense Organs

“…341,342 Strain and species differences in sensitivity to cataract induction by xenobiotics are illustrated by studies with paracetamol (acetaminophen), a widely used analgesic and antipyretic that has been shown to cause cataracts in mice. 341,342 Strain and species differences in sensitivity to cataract induction by xenobiotics are illustrated by studies with paracetamol (acetaminophen), a widely used analgesic and antipyretic that has been shown to cause cataracts in mice.…”