Light and myopia: from epidemiological studies to neurobiological mechanisms

Abstract

Myopia is far beyond its inconvenience and represents a true, highly prevalent, sight-threatening ocular condition, especially in Asia. Without adequate interventions, the current epidemic of myopia is projected to affect 50% of the world population by 2050, becoming the leading cause of irreversible blindness. Although blurred vision, the predominant symptom of myopia, can be improved by contact lenses, glasses or refractive surgery, corrected myopia, particularly high myopia, still carries the risk of secondary blinding complications such as glaucoma, myopic maculopathy and retinal detachment, prompting the need for prevention. Epidemiological studies have reported an association between outdoor time and myopia prevention in children. The protective effect of time spent outdoors could be due to the unique characteristics (intensity, spectral distribution, temporal pattern, etc.) of sunlight that are lacking in artificial lighting. Concomitantly, studies in animal models have highlighted the efficacy of light and its components in delaying or even stopping the development of myopia and endeavoured to elucidate possible mechanisms involved in this process. In this narrative review, we (1) summarize the current knowledge concerning light modulation of ocular growth and refractive error development based on studies in human and animal models, (2) summarize potential neurobiological mechanisms involved in the effects of light on ocular growth and emmetropization and (3) highlight a potential pathway for the translational development of noninvasive light-therapy strategies for myopia prevention in children.

The Connection between High Myopia Patients and MiR-708a or MiR-148 Expression Levels in Aqueous Studies of Visual Acuity

“…Without enough intervention, the current prevalence of myopia is supposed to 50% of the world's population by 2050 and become the main reason of irreversible blindness. Though the main symptom blurred vision can be improved through contact lenses, glasses, or refractive surgery, correcting myopia, especially HM, is still in risk of secondary blinding complications, like myopic maculopathy, glaucoma, and retinal detachment, so it needs to be prevented [ 28 ]. This is particularly of concern for HM patients [> −5 Dioptres (D)] who have the risk of pathologic myopia and other related eye diseases such as retinal detachment, choroidal neovascularization, glaucoma, and myopic macular degeneration [ 29 , 30 ].…”

Detection of adaptation to light environment in myopia-associated loci Diversity of the myopia genetic background

“…This study aimed to understand the diversity in the genetic background of myopia from an evolutionary perspective, and provide evidence of local adaptation to the sunlight environment in the retina. The protective effect of bright sunlight against myopia progression in humans6-10 and animal models of chickens, guinea pigs, tree shrews, mice, and some nonhuman primates[44,45,46] implies that adaptation to sunlight conditions in the eyes is long known, conserved, and remains active. In this case, the evolutionary history of the genetic background of myopia highly conforms to traits shaped by light-related adaptation[17], such as pigmentation, and eventually played a role in myopia prevalence divergence.…”

Empfehlungen bei progredienter Myopie im Kindes- und Jugendalter. Stellungnahme von DOG, BVA und der Bielschowsky Gesellschaft für Schielforschung und Neuroophthalmologie

“…Grundsätzlich ist eine gezielte Information sinnvoll, welche Verhaltensmaßnahmen zum Auftreten einer Myopie und zur Abnahme einer Progression beitragen können: Lichtexposition Eine ausreichende Aufenthaltszeit im Freien zeigte schon mit relativ geringen Lichtintensitäten (1000 lx) positive Auswirkungen [ 19 ]. Die tägliche Exposition sollte besonders auch im Winter beachtet werden bzw.…”

“…Eine ausreichende Aufenthaltszeit im Freien zeigte schon mit relativ geringen Lichtintensitäten (1000 lx) positive Auswirkungen [ 19 ]. Die tägliche Exposition sollte besonders auch im Winter beachtet werden bzw.…”