Abstract

The aim of this study was to evaluate the morphometry and ultra structure of retinal pigmented layer in continuous light exposed and dark adapted domestic female cats. Twenty four healthy adult cats were divided into three groups: control, continuous light exposed and continuous dark adapted groups. The eyes of animals were routinely fixed and studied by electron microscope. The results showed that in light exposed group, the mean of thickness and number of melanosome of retinal pigmented layer had significant increment when compared with  control and dark adapted groups (P<0.05). Mitochondria, golgi apparatus and rough endoplasmic reticulum were also observed to increase in the light exposed group. Our finding have confirmed that high cell activity occur in cat retinal pigmented layer under the effect of 24 h continuous light.

Key words: Morphometry, ultra structure, retinal pigmented layer, cat.