THESIS DEFENSE — PUBLIC SEMINAR: Assessment of Photoreceptor Function Using The Pupillary Light Reflex

Start Date & Time: 
Monday, 3 October, 2016 - 10:30
End Date & Time: 
Monday, 3 October, 2016 - 11:30
Venue: 

Training Room 5C, Level  5,
Duke-NUS

Speaker: 
Speaker Details: 

ANNADATA  VENKATA RUKMINI
IBM PhD PROGRAM (INTAKE 2011)

Synopsis: 

The pupillary light reflex is mediated by rods, cones, and melanopsin-containing retinal ganglion cells (RGCs), which differ in their response characteristics. Hence, pupillary responses to different wavelengths and intensities of light can potentially be used to assess the functional integrity of the inner versus outer retina. Here, a novel light exposure protocol was developed in which a gradually increasing blue light (469nm) or red light (631nm) stimulus was used to activate rods, cones, and melanopsin sequentially. In patients with glaucoma, deficits in pupillary constriction to high-irradiance blue light correlated with disease severity, suggesting comparable damage to melanopsin cells and RGCs that mediate vision. Ageing was associated with reduced pupillary light responses, but age-dependent yellowing of the lens and cataracts did not selectively reduce pupillary responses to blue light. These experiments demonstrate that a short-duration chromatic pupillometry test can potentially be used to screen retinal health in ageing and ocular diseases.

Thesis Advisor: A/Prof Joshua Gooley