Pregnancy Signs & Symptoms, Week by Week Pregnancy Guide

The latest edition of the journal Nature has published a paper that emphasizes the importance of light exposure during pregnancy for normal eye development in the baby. This research was conducted by scientists at the University of California, San Francisco. The finding is particularly useful in understanding ocular diseases caused due to vascular disorders especially ones like retinopathy of premature infants which can lead to blindness.

The study was set up with the primary objective of identifying the light-response pathway which controls retinal neurons. Richard Lang, the principal investigator of the project along with fellow scientist David Copenhagen set up the initial experiments on laboratory mice. For this, the mice were divided into 2 groups – one where the mice were kept in the dark, and the other where the mice were allowed exposure to normal light. They introduced a marker in the ‘opsin’ gene so that the pathway and its effect could be identified. Using these molecular tools, the scientists deciphered the functions of the light response pathway and how it was affecting the infants leading to retinopathy and other vascular diseases of the eye in them.

Function of the Light Response Pathway

Using these mouse models the researchers demonstrated that:

1. The activation of the light-response pathway must occur during pregnancy in order to produce a healthy eye at the time of birth.
2. They showed that this activation process has to be completed by about 16 days into the gestational period of a mouse. For humans, the period translates into last trimester. For this to happen a certain number of photons have to enter into the mother’s body.
3. Later it was also showed that the photons activate melanopsin, a protein present in the fetus that initiates normal vascular development and retinal neurons as well.
4. Another function of the pathway is suppressing the vascular system of the retina which supplies large amounts of oxygen to the retinal neurons. Retinopathy occurs when this suppression is hindered leading to uncontrolled growth of the retinal blood vessels, which puts pressure on the eye leading to irreversible damage and even blindness.