- Light therapy in preterm infants is useful in preventing vision problems by activating a protein called opsin 5 that regulates the development of blood vessels in the eye which is critical for normal vision
- In preterm infants, there is a decreased expression of the opsin 5 protein and normal development of eye blood vessels is therefore affected leading to vision problems
- Eye conditions such as retinopathy of prematurity and severe myopia (near-sightedness) are common in preterm infants
Role of Opsin 5 & Dopamine in Normal Blood Vessel Development in Eye
- To see what happens when opsin 5 protein is not expressed in the retinal cells (similar to what is seen in preterm infants) the scientists used genetically modified mice to test the response
- They found that loss of opsin 5 led to increased levels of dopamine in the eye.
- The increased dopamine levels caused developing blood vessels to regress rapidly affecting normal visual development
- Activation of opsin 5 protein resulted in reduced dopamine levels in the eye, thus favoring optimal blood vessel development and normal vision
What is the Opsin 5-Dopamine Pathway?
- The opsin 5-dopamine pathway is a molecular process occurring in the developing eyes of the baby
- This process depends on specific responses in the retina controlled by opsin 5, a protein that is normally expressed in specialized light receptor cells in the retina
- The opsin 5 protein normally becomes activated by light exposure at the right time to ensure normal vision
- The activated opsin 5 along with the neurotransmitter dopamine (which causes blood vessel loss) work together to ensure optimal and balanced blood vessel development in the eye of the newborn
Scope of the Study
- In fact, earlier studies have suggested that dopamine together with violet light may be critical to the normal development of the eye
- Although, additional research is needed for the findings to be applied to humans, the current study confirms that opsin 5-dopamine pathway is key for normal vision development in mice and perhaps human babies as well
- According to one of the authors, opsin 5 is protein highly conserved across species during the process of evolution, and increases the likelihood of its presence and importance in humans as well
SummaryThe findings of the study show that the opsin 5-dopamine pathway is necessary for balanced blood vessel formation in the newborn and phototherapy may be useful to prevent eye problems in preterm infants.
- An opsin 5–dopamine pathway mediates light-dependent vascular development in the eye - (http://dx.doi.org/10.1038/s41556-019-0301-x)