Light: Key Factor to Foetal Eye Development

Rebecca Lewis January 18, 2013

Scientists at the Cincinnati Children’s Hospital Medical Centre and University of California, San Francisco (UCSF) found that light, which the eye depends on to see, is also necessary for its development particularly during conception.

This finding gives a better understanding to the nature of foetal eye development and ocular diseases caused by vascular nerve damage.

Dr Richard Lang, the lead researcher from the Division of Paediatric Ophthalmology at Cincinnati Children’s Hospital Medical Centre, said they have identified a light-response pathway that controls most of the retinal neurons. According to him, the pathway has downstream effects on the development of the vasculature in the eye. Knowing this is very important because several major ocular problems are caused by vascular damage.

Unexpected Findings

The researchers have assumed that since several stages of ocular development happen after birth, the role of light in the development of the eye would also happen after birth. However, this was not the case.

For the study, the team reared laboratory mice in a dark and normal-day cycle beginning at late gestation to observe the comparative effects of light to the vascular development in the eye. They mimicked the function of light response pathway in humans by mutating a gene in the mice called Opn4. This gene is responsible for producing melanopsin – a protein that prevents the activation of photo pigment in the eye. Melanopsin is present in both mice and humans during pregnancy.

Researchers found that for the body to produce a healthy eye, the activation of the light-response pathway must happen during pregnancy. They also discovered that photons of light activate melanopsin directly in the foetus to help regulate the growth of blood vessels and retinal neurons.

According to the team, in retinopathy of prematurity that occurs in infants, retinal neurons tend to grow faster and bigger. Such continued expansion puts great pressure in the eye and could later on lead to damage, even blindness. The light-response pathway is essential in suppressing the speedy growth of neurons in the retina, paving way to normal eye development.

Lang and his colleagues further suggest that it is important for a sufficient number of photons to enter the mother’s body during late gestation.

Their report was recently published in the journal Nature.

Source of this article:

Light Exposure During Pregnancy Key to Normal Eye Development