Age-dependent changes in glutathione metabolism pathways in the lens: New insights into therapeutic strategies to prevent cataract formation-A review.

Ocular tissues possess a robust antioxidant defence system to minimize oxidative stress and preserve tissue structure and function. Glutathione (GSH) is a powerful antioxidant and in the lens exists at unusually high concentrations. However, with advancing age, GSH levels deplete specifically in the lens centre initiating a chain of biochemical events that ultimately result in protein aggregation, light scattering and age-related nuclear cataract. However, antioxidant supplementation has been shown to be ineffective in preventing or delaying cataract indicating that a better understanding of the delivery, uptake and metabolism of GSH in the different regions of the lens is required. This information is essential for the development of scientifically informed approaches that target the delivery of GSH to the lens nucleus, the region of the lens most affected by age-related cataract.