Neuroendocrine responses to light in people without daylight vision: Patient engagement

Manuel Spitschan, Psychiatric Hospital of the University of Basel (UPK)

 

Aims

Light exposure in the evening and at night strongly affects the human neuroendocrine system by suppressing the production of melatonin. This is largely mediated by the melanopsin-containing retinal ganglion cells in the eye, but there is converging evidence that the dim-sensitive rods and the daylight-sensitive cones also participate in this process. Patients with the rare condition congenital achromatopsia (prevalence 1:30,000-50,000) lack a functional cone system and only 'see' using their rods. As a consequence, they are extremely sensitive to daytime light levels, including typical outdoor illumination. How neuroendocrine responses to light are affected by the absence of daylight vision is at present not known. 

In this project, performed during a research visit at the Centre for Chronobiology in Basel, we will build on a previous relationship with a well-described group of genetically confirmed congenital achromats to further understand how light affects their neuroendocrine system. Specifically, we will:

(1) Examine the patterns and regularity of the day-to-day light exposure to identify opportunities for improving their light exposure and activity timing to support the entrainment of their circadian rhythms to the external-light dark cycle;
(2) Examine and improve the trade-off between visual comfort and circadian response of filtered glasses and contact lenses typically used by congenital achromats using computer simulations and informed models of circadian photoreception.

 

Grant awarded: €2,000