Tools to fight the cataract epidemic: A review of experimental animal models that mimic age related nuclear cataract

Cataract is the leading cause of blindness worldwide and accounts for approximately half of all forms of vision loss. Currently, the only way to treat cataracts is by surgery. However, with an ageing population, the demand for surgery and the need for cost effective alternative solutions grows exponentially. To reduce the need for cataract surgery, alternative medical therapies to delay cataracts are urgently required. However, given the difficulty in accessing human cataract lenses, investigating the process of cataract formation and testing the efficacy of potential therapies in humans is problematic. Therefore, researchers have looked to create suitable animal models of cataractogenesis to identify therapeutic options. This review will provide an overview of the cataract specific changes previously reported in human cataract lenses, before focussing on the specific changes that occur in age related nuclear (ARN) cataract, the most common form of cataract in humans. This will be followed by a discussion of a range of existing animal cataract models and their respective suitability for mimicking the processes associated with the development of ARN cataract, and therefore their utility as models to test anti-cataract therapies for future use in humans.