47.: Effects of stimulating melanopsin-containing retinal ganglion cells in migraine patients using multifocal objective pupillometry

Abstract

Recent evidence has linked intrinsically-photosensitive retinal ganglion cells (ipRGC) to photosensitivity in migraine. It is possible that multifocal pupillographic objective perimetry (mfPOP) might exacerbate migraine and the response to mfPOP might be different in migraineurs. This study aimed to establish the effects of stimulating ipRGC using mfPOP on migraine severity parameters and pupillary response characteristics. A randomized case-control crossover study tested migraineurs and normal controls using mfPOP utilising a blue protocol to target the intrinsic melanopsin response of the ipRGC and a yellow protocol to stimulate cone photoreceptors. Migraine diaries were obtained a week prior to and a week after each testing. Responses were analysed according to response time-to-peak and standardised amplitude (AmpStd). The percentage area under the receiver operator characteristic curve (%AUC) was used to predict migraine status. Thirty-eight migraineurs and 24 normal controls were enrolled. There was no significant difference in the mean number of migraine attacks/subject in the weeks prior to, or following, testing with either protocol. The AmpStds (in dB) were lower for migraineurs than controls, though these differences did not reach statistical significance. A migraine attack occurring in the 2 weeks prior to testing had a significant independent effect in lowering AmpStd while a history of triptan use increased AmpStd. Time-to-peak was shorter in yellow protocol, probably related to differences in the stimuli. The %AUC was highest for AmpStd. Stimulating ipRGC did not affect migraine severity. Pupillary response characteristics were influenced by recent attacks of a migraine and a history of triptan use.