title: The post-illumination pupil response of melanopsin-expressing intrinsically photosensitive retinal ganglion cells in diabetes.
abstract: OBJECTIVE
  This study investigates the clinical utility of the melanopsin-expressing intrinsically photosensitive retinal ganglion cell (ipRGC) controlled post-illumination pupil response (PIPR) as a novel technique for documenting inner retinal function in patients with Type II diabetes without diabetic retinopathy.
  
  
  METHODS
  The PIPR was measured in seven patients with Type II diabetes, normal retinal nerve fibre thickness and no diabetic retinopathy compared to healthy age-similar controls. A 488- and 610-nm, 7.15-diameter stimulus was presented in Maxwellian view to the right eye and the left consensual pupil light reflex was recorded.
  
  
  RESULTS
  The group data for the blue PIPR (488 nm) identified a trend of reduced ipRGC function in patients with diabetes with no retinopathy. The transient pupil constriction was lower on average in the diabetic group. The relationship between duration of diabetes and the blue PIPR amplitude was linear, suggesting that ipRGC function decreases with increasing diabetes duration.
  
  
  CONCLUSIONS
  This is the first report to show that the ipRGC-controlled PIPR may have clinical applications as a non-invasive technique for determining the progression of inner neuroretinal changes in patients with diabetes before they are ophthalmoscopically or anatomically evident. The lower transient pupil constriction amplitude indicates that outer retinal photoreceptor inputs to the pupil light reflex may also be affected in diabetes.
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane 4059, Queensland, Australia. andrew.zele@qut.edu.au
authors: Beatrix
authors: B
authors: Feigl
authors: Andrew J
authors: AJ
authors: Zele
authors: Samantha M
authors: SM
authors: Fader
authors: Annelisa N
authors: AN
authors: Howes
authors: Catherine E
authors: CE
authors: Hughes
authors: Kris A
authors: KA
authors: Jones
authors: Rawlyn
authors: R
authors: Jones
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000528:radiation effects*; D012025:Reflex, Pupillary / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D017299:Rod Opsins / Q000378:metabolism*; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin