Bioactive Properties of Carotenoids in Ocular Diseases: Antioxidant, Anti-Inflammatory, and Neuroprotective Effects.

Ocular diseases are a significant public health problem worldwide and represent one of the leading causes of disability. The prevalence of visual impairment is steadily increasing, largely driven by the ageing population. Oxidative stress, chronic inflammation and neurodegenerative processes underlie the pathogenesis of many eye diseases, including age-related macular degeneration (AMD), diabetic retinopathy, glaucoma, and cataracts, contributing to progressive vision loss and functional impairment. Carotenoids such as lutein, zeaxanthin, meso-zeaxanthin, β-carotene, lycopene, and astaxanthin exhibit multidirectional biological effects, including antioxidant, anti-inflammatory, and neuroprotective properties. These compounds are selectively accumulated in the tissues of the eye, especially in the retina and macula, where they neutralise reactive oxygen species, modulate inflammatory pathways, stabilise mitochondrial function and support the survival and function of retinal ganglion cells and photoreceptors. The aim of our review was to provide a comprehensive review of current data regarding the mechanisms of action of carotenoids and their potential clinical significance in the prevention and treatment of retinal, optic nerve, lens, and eye surface diseases, including dry eye syndrome and Meibomian gland dysfunction. We identified results of available experimental and clinical research and outlined that an adequate supply of carotenoids in the diet or in the form of supplementation may support the protection of eye structures against oxidative and inflammatory damage, improve visual performance and potentially slow disease progression. However, high-quality prospective clinical trials are necessary to conclusively assess their therapeutic efficacy and establish evidence-based recommendations for clinical practice.