RT Journal Article
A1 Mutti, Donald O.
A1 Mulvihill, Shane P.
A1 Orr, Danielle J.
A1 Shorter, Patrick D.
A1 Hartwick, Andrew T. E.
T1 The Effect of Refractive Error on Melanopsin-Driven Pupillary Responses
JF Investigative Ophthalmology & Visual Science
JO Invest. Ophthalmol. Vis. Sci.
YR 2020
DO 10.1167/iovs.61.12.22
VO 61
IS 12
SP 22
OP 22
SN 1552-5783
AB    Human and animal studies suggest that light-mediated dopamine release may underlie the protective effect of time outdoors on myopia development. Melanopsin-containing retinal ganglion cells may be involved in this process by integrating ambient light exposure and regulating retinal dopamine levels. The study evaluates this potential involvement by examining whether melanopsin-driven pupillary responses are associated with adult refractive error.    Subjects were 45 young adults (73% female, 24.1 ± 1.8 years) with refractive errors ranging from –6.33 D to +1.70 D. The RAPDx (Konan Medical) pupillometer measured normalized pupillary responses to three forms of square-wave light pulses alternating with darkness at 0.1 Hz: alternating long wavelength (red, peak at 608 nm) and short wavelength (blue, peak at 448 nm), followed by red only and then blue only.    Non-myopic subjects displayed greater pupillary constriction in the blue-only condition and slower redilation following blue light offset than subjects with myopia (P = 0.011). Pupillary responses were not significantly different between myopic and non-myopic subjects in the red-only condition (P = 0.15). More hyperopic/less myopic refractive error as a continuous variable was linearly related to larger increases in pupillary constriction in response to blue-only stimuli (r = 0.48, P = 0.001).     Repeated light exposures to blue test stimuli resulted in an adaptation in the pupillary response (more constriction and slower redilation), presumably due to increased melanopsin-mediated input in more hyperopic/less myopic adults. This adaptive property supports a possible role for these ganglion cells in the protective effects of time outdoors on myopia development.  
RD 4/23/2021
UL https://doi.org/10.1167/iovs.61.12.22