Nutritional and Metabolic Imbalance in Keratoconus

Abstract

Keratoconus (KC) is a progressive corneal degeneration characterized by structural changes consisting of progressive thinning and steepening of the cornea. These alterations result in biomechanical weakening and, clinically, in vision loss. While the etiology of KC has been the object of study for over a century, no single agent has been found. Recent reviews suggest that KC is a multifactorial disease that is associated with a wide variety of genetic and environmental factors. While KC is typically considered a disease of the cornea, associations with systemic conditions have been well described over the years. In particular, nutritional and metabolic imbalance, such as the redox status, hormones, metabolites, and micronutrients (vitamins and metal ions), can deeply influence KC initiation and progression. In this paper, we comprehensively review the different nutritional (vitamins and minerals) and metabolic (hormones and metabolites) factors that are altered in KC, discussing their possible implication in the pathophysiology of the disease.

Distribution of pediatric keratoconus by different age and gender groups

“…A gender-related difference is believed to play an important role in changes in corneal tissue structures ( 27 – 30 ). Male patients account for a higher proportion than female patients based on previous investigations of adult keratoconus ( 7 , 9 , 10 , 31 , 32 ).…”

“…Males have higher levels of androgens, while females have a higher estrogen level ( 34 , 35 ). The cornea expresses multiple receptors and enzymes for sex hormone metabolism and cellular activities, which further bind to sex hormones, leading to hormonal level changes and further causing other anatomic and physiological differences between males and females ( 9 , 30 , 36 ). In addition, the male/female ratio decreased with age in the current analysis.…”

Role of Oxidative Stress in Ocular Diseases: A Balancing Act

“…Untargeted mass spectrometry analysis of human serum from a small case–control study revealed increased dehydroepiandrosterone sulfate and prostaglandins in patients with KC compared to age-matched controls [ 85 ], which is consistent with a study by our group [ 86 ] and others [ 87 , 88 ] associating altered hormone levels or their receptors with KC. Growing evidence supports the hypothesis that there is a systemic component involved in KC pathogenesis upstream of the endogenous oxidative stress observed in the cornea [ 89 , 90 ].…”

Corneal wound healing and nerve regeneration by novel ophthalmic formulations based on cross-linked sodium hyaluronate, taurine, vitamin B6, and vitamin B12

“…Previous studies demonstrated the importance of vitamins in maintaining ocular surface homeostasis, suggesting the possible protective effects against damages ( Lasagni Vitar et al, 2022 ). Vitamins are essential for many corneal functions and help ensuring corneal integrity supporting the epithelial barrier and cells survival ( Yin et al, 2011 ; Bucolo et al, 2015 ; Reins et al, 2015 ; Gozzo et al, 2021 ; Kaminska et al, 2021 ; Lasagni Vitar et al, 2022 ). Moreover, their anti-inflammatory, antimicrobial and antioxidant properties have been demonstrated ( Wimalawansa, 2019 ).…”