Food Supplements in the Treatment of Ophthalmic Diseases: Preclinical and Clinical Studies

Among the 2.2 billion people in the world affected by any type of eye condition, the World Health Organization estimates 196 million with Age-related Macular Degeneration (AMD), 146 million with diabetic retinopathy (DR) and 76 million with glaucoma [1]. No clear estimate exists on the global presence of dry eye, though the English Agency known as Global-Data UK Ltd. in a document published on June 2018, considering the 8 more industrialised Countries (US, France, Germany, Italy, Spain, UK, Japan, and China), reports a prevalence of 267,680,785 cases in 2016, destined to raise to 286,308,974 cases in 2026, therefore with an annual growth rate of 0.70% [2]. Approximately 200 million eyes globally are affected by cataracts causing a visual acuity less than 6/60, which become 3-4 times more including cataracts causing an acuity below 6/18 [3], accounting for one third of the worldwide blindness [4]. Globally, over 300 millions adolescents (less than 19 years old) are affected by progressive myopia [1], which in older ages may bring serious complications, like glaucoma or retinal detachment. All these eye pathologies pose a serious threat to vision, and have a strong social and economic impact. It has been estimated in 2014 by the National Eye Institute that the annual economic burden of vision loss, eye diseases and vision disorders in the U.S. amounted to 139 billion $ [5]. Now, what all these pathologies have in common is that there is no efficient pharmacological treatment for any of them. Resolutive surgery is possible in the case of cataract, but it is not devoid of – although minimal – side effects [6]. Surgical approaches are routinary applied also to the other pathologies, but most often they are not curative, and can at best attenuate their progression [7,8]. However, for all of them there is a link with lifestyle and alimentary habits, which becomes more evident in older ages [9,10]. This opens a space Review Article