The light women see during pregnancy may play a huge role in healthy eye development in the fetus. According to research recently published in the journal Nature, light promotes release of the protein melanopsin, but the protein is only released in the fetus. Melanopsin, present in both mice and humans, may play a more important part in healthy eye development than doctors and researchers thought.
The study was performed on lab mice, but researchers believe the similarities between mouse and eye development suggest similar effects in humans. Three groups were used for study - total darkness, Opn4 suppression and normal day/night. Opn4 is the opsin gene that regulates melanopsin production. Mice in this group were genetically altered to produce no melanopsin.
Both the total darkness and Opn4 groups showed signs of abnormal retinal development after birth. Abnormal growth of retinal vessels and hyaloids vessel expansion were noted. Vegfa (vascular endothelial growth factor) is the protein thought to be responsible for keeping vascular growth under control. Vegfa did not perform adequately when the fetus did not produce adequate amounts of melanopsin.
In humans, retinopathy of prematurity (ROP) may be associated with melanopsin and Vegfa production. Researchers believe this study may shed light on retinal development and ROP. ROP can cause blindness in premature infants. Prior to the study, researchers believed the majority of eye development occurred after birth, but according to study findings presence of light in the latter stages of pregnancy may a key role.
Retinopathy of prematurity is not the only vascular disorder of the eye, but it is the most dangerous for preterm infants. Vascular diseases also play a part in eye health in patients with diabetes. With additional research, the findings of this study may prove beneficial for all patients with vascular eye disease. According to Richard Land PhD from the Cincinnati Children’s Hospital, “We have identified a light-response pathway that controls the number of retinal neurons. This has downstream effects on developing vasculature in the eye and is important because several major eye diseases are vascular diseases.”
Source: Sujata Rao, Christina Chun, Jieqing Fan, J. Matthew Kofron, Michael B. Yang, Rashmi S. Hegde, Napoleone Ferrara, David R. Copenhagen, Richard A. Lang. A direct and melanopsin-dependent fetal light response regulates mouse eye development. Nature, 2013; DOI: 10.1038/nature11823