Summary
This thesis characterized the temporal, spatial, and adaptation properties of melanopsin-driven contributions to the human pupil light reflex, finding that melanopsin inputs are timing-independent but sensitive to spatial location and adaptation state. The findings establish objective biomarkers of melanopsin function that could be translated into clinical diagnostic tools for eye and brain diseases, with broader implications for understanding how intrinsically photosensitive retinal ganglion cells contribute to non-visual light responses relevant to circadian lighting design.
Key Findings
- Melanopsin inputs to the pupil light reflex are independent of stimulus timing (phase of presentation) but are sensitive to stimulus spatial location within the visual field.
- Melanopsin contributions to the PLR are modulated by adaptation level, suggesting that background light history affects intrinsically photosensitive retinal ganglion cell (ipRGC) responsiveness.
- New functional measures of melanopsin cell activity were developed, providing objective biomarkers potentially usable in clinical diagnosis of conditions involving dysfunctional melanopsin signaling.
Categories
The Science of Light: Directly investigates melanopsin cell function, photoreceptor biology, and the pupillary light reflex with implications for lighting standards and biomarker development.
Eye Health & Vision: Develops clinical tools based on melanopsin-driven PLR measurements for diagnosing and monitoring eye and brain disorders affecting photoreceptor function.
Author(s)
DS Joyce
Publication Year
2016
Number of Citations
1
Related Publications
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice
Eye Health & Vision
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Genetic reactivation of cone photoreceptors restores visual responses in retinitis pigmentosa
- Melanopsin and rod–cone photoreceptors play different roles in mediating pupillary light responses during exposure to continuous light in humans
- Characteristic patterns of dendritic remodeling in early-stage glaucoma: evidence from genetically identified retinal ganglion cell types
- Intrinsically photosensitive melanopsin retinal ganglion cell contributions to the pupillary light reflex and circadian rhythm