Blue-Light Stimulation for Myopia Prevention: Only Retinal but Not Optic Disc Stimulation Modulates the Pattern ERG

Blue-light stimulation of the optic disc has been suggested as a means of myopia prevention by activating dopaminergic amacrine cells via intrinsically photosensitive retinal ganglion cells. This prospective, adequately powered study investigated this approach by examining its effects on pattern electroretinogram (PERG) N95 amplitude and choroidal thickness (ChT), established biomarkers associated with retinal ganglion cell function and myopia progression, respectively. Forty-six healthy adults received one minute of 450 nm blue-light stimulation to either the optic disc or central retina of the right eye, with the fellow left eye serving as control. PERG responses were measured before and 20 min after stimulation (N = 15 per stimulation location), while ChT, using swept-source optical coherence tomography images, was measured before, 20, and 60 min after stimulation (N = 8 per stimulation location). Only retinal stimulation significantly increased PERG N95 amplitude (baseline 16.16 µV, post-stimulation 17.61 µV [<i>p</i> = 0.01]), whereas optic disc stimulation did not (baseline 18.71 µV, post-stimulation 18.81 µV [<i>p</i> = 0.76]). Neither optic disc nor retinal stimulation significantly changed ChT at any time point. No significant differences were observed between myopic and non-myopic participants. Our findings do not support the hypothesis that short-duration blue-light stimulation of the optic disc is a viable strategy to activate retinal dopaminergic pathways for myopia prevention.