The association of visual impairment and poor diet has long been recognized. The
retina and retinal pigment epithelium have the highest trace mineral content as
compared to any body tissue. Malnutrition as a cause of blindness has been under
estimated. This study aimed to investigate the relation between both deficiency as well
as the excess of micronutrients (Vitamin A, zinc and iron) and the ocular eye diseases.
This work was done on 48 albino rats divided into six groups. Group one fed on
control basal diet, group two, three and four were fed on a diet free from vitamin A,
iron, and zinc respectively. Group five was fed on a diet free from all the above
micronutrients while group six was fed on a diet contain excess of all these
micronutrients. At the end of the feeding period, ophthalmological and histological
examinations were done to all rats. The level of vitamin A was estimated in the serum
and the concentration of zinc and iron were determined in the cornea, lens and retina.
Also total protein and its fractions were estimated in the lens. The result of this study
showed that cortical cataract was detected in the rats fed on the diet containing
deficient or excess micronutrients. The level of vitamin A in serum and the
concentration of iron and zinc in cornea, lens and retina revealed a significant
change in different tissues studied due to different treatment especially in deficient
and excess groups. Histological examination revealed photoreceptor degeneration in
the retina and intact endothelial cells of the cornea. The data of this work also
revealed that the level of these micronutrients in the diet affect ocular function,
therefore they have to be provided in adequate amounts that satisfy the physiological
requirements to avoid eye complications.