title: Intrinsically photosensitive (melanopsin) retinal ganglion cell function in glaucoma.
abstract: OBJECTIVE
  To determine whether glaucoma alters intrinsically photosensitive retinal ganglion cell (ipRGC) function.
  
  
  METHODS
  Forty-one patients (25 with glaucoma and 16 healthy age-matched control participants) were tested. Intrinsically photosensitive retinal ganglion cell function was directly measured by the sustained, postillumination pupil response (PIPR). Forty-one eyes of 41 participants were tested with 7°, 10-second, short-wavelength (488 nm; bluish) and long-wavelength (610 nm; reddish) stimuli (14.2 log photons · cm(-2) · s(-1)) presented to the right eye in Maxwellian view, and the consensual pupil response of the left eye was measured by infrared pupillometry. The difference between PIPR amplitude (percentage baseline pupil diameter), net PIPR (percentage change) and kinetics (time in mm · s(-1) to the PIPR plateau) for the blue and red stimuli in patients with early and advanced (moderate/severe) glaucoma was compared to that in age-matched control participants.
  
  
  RESULTS
  The blue PIPR was significantly smaller between normal participants and patients with advanced glaucoma, as well as between those with early and those with advanced glaucoma (P < 0.05). The kinetics of the red and blue PIPRs were not significantly different between any groups. Normal age-matched participants and patients with early-stage glaucoma were not significantly different on any parameter, and neither was the normal and glaucoma group (advanced and early combined).
  
  
  CONCLUSIONS
  Persons with moderate and severe glaucoma have a dysfunctional ipRGC-mediated PIPR. Intrinsically photosensitive retinal ganglion cell function measured directly with the PIPR may become a clinical indicator of progressive changes in glaucoma.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia. b.feigl@qut.edu.au
authors.forename: Beatrix
authors.initials: B
authors.lastname: Feigl
authors.forename: Dietmar
authors.initials: D
authors.lastname: Mattes
authors.forename: Ravi
authors.initials: R
authors.lastname: Thomas
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Zele
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D012165:Retinal Ganglion Cells / Q000502:physiology*; D017299:Rod Opsins / Q000378:metabolism*; D012720:Severity of Illness Index; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin