Ultrastructural changes in the developing chicken cornea following caffeine administration.

Abstract

Caffeine is one of the most frequently consumed psychoactive substances. It has been known for many years that caffeine at high concentrations exerts harmful effects on both women's and laboratory animals' fertility, moreover it may impair normal development of many organs in the prenatal period. So far there have been few studies performed that demonstrate teratogenic effects of caffeine on structures of the developing eye, particularly the cornea. The aim of the study was to show ultrastructural changes in the developing cornea, as the effect of caffeine administration to chicken embryos. The experimental materials were 26 chicken embryos from incubated breeding eggs. Eggs were divided into two groups: control (n=30) in which Ringer liquid was administrated, and experimental (n=30) in which teratogenic dose of caffeine 3.5mg/egg was given. In 36th hour of incubation solutions were given with cannula through hole in an egg shell directly onto amniotic membrane. After closing the hole with a glass plate and paraffine, eggs were put back to incubator. In 10 th and 19 th day of incubation corneas were taken for morphological analysis with a use of electron microscopy. Administration of caffeine during chicken development causes changes of collagen fibers of Bowman's membrane patterns and of the corneal stroma but it also changes proportion of amount of collagen fibers and of the stromal cells.

The acute effects of single cup of coffee on ocular biometric parameters in healthy subjects

“…Kujawa-Hadryś et al. demonstrated that caffeine causes changes of collagen fiber pattern in Bowman's membrane and corneal stroma 26 and decreases the total thickness of developing chick embryo cornea 27 . Evereklioglu et al.…”

Effect of Single Administration of Coffee on Pupil Size and Ocular Wavefront Aberration Measurements in Healthy Subjects

“…Animal studies have found that caffeine, when applied topically, prevents apoptosis and removes reactive oxygen species in lens, thus having anticataractogenic effect [ 20 , 21 ]. Moreover, it has been demonstrated that administration of caffeine causes changes of collagen fibers of Bowman's membrane and corneal stroma along with alterations in the amount of collagen fibers and stromal cells in developing chicken corneas [ 22 ]. Evereklioglu et al [ 23 ] have shown that high dose of caffeine administration to pregnant rats leads to histopathological changes in the cornea of newborn rats including vacuolated endothelial cells with proliferation, hyperchromasia, polymorphism, endothelial cell agenesis, increased stromal mitotic activity, and focal increase in corneal thickness with widely separated corneal lamellae.…”

Excess caffeine exposure impairs eye development during chick embryogenesis

“…In addition, the orbital bone, which is the accessory structure of the eye, was deficient after caffeine treatment. It has been reported that excess caffeine causes changes to the cornea and the failure of neural tube closure because of excessive neuroepithelial cell proliferation . In rat embryos, up to 91% of the caudal neural tubes failed to close following caffeine treatment .…”