title: Age-related cataract and drug therapy: opportunities and challenges for topical antioxidant delivery to the lens.
abstract: OBJECTIVE
  The search for anticataract drugs has been continuing for decades; some treatments no longer exist but antioxidants are still of much interest.
  
  
  RESULTS
  The primary function of the human lens, along with the cornea, is to refract light so that it is correctly focused onto the retina for optimum image quality. With age, the human lens undergoes morphological, biochemical and physical changes leading to opacification. Age-related or senile cataract is one of the main causes of visual impairment in the elderly; given the lack of access to surgical treatment in many parts of the world, cataract remains a major cause of sight loss. Surgical treatment is the only means of treating cataract; this approach, however, has limitations and complications.
  
  
  CONCLUSIONS
  This review discusses the anatomy and physiology of the lens and the changes that are understood to occur with ageing and cataract formation to identify potential areas for effective therapeutic intervention. Experimental techniques and agents used to induce cataract in animal models, the advantages and disadvantages of potential pharmacological treatments specific barriers to delivery of exogenous antioxidants to the lens and the prospects for future research are discussed.
authors: Drug Discovery, Delivery and Patient Care (DDDPC) Theme, School of Pharmacy and Chemistry, Kingston University London, London, UK; Pharmaceutics Department, Faculty of Pharmacy, Minia University, Mina, Egypt.
authors: Hamdy
authors: H
authors: Abdelkader
authors: Raid G
authors: RG
authors: Alany
authors: Barbara
authors: B
authors: Pierscionek
mesh_terms: D000287:Administration, Topical; D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D002386:Cataract / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism / Q000473:pathology; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D009883:Ophthalmic Solutions
keywords: antioxidants; aspirin; bendazac and naltrexone; carnosine; carotenoids; cataract; crystallins; flavonoids; ocular delivery