[Apoptosis and the ocular surface].
Apoptosis, or programmed cell death, is an active phenomenon that plays a major role in most mechanisms of regulation, differentiation and wound healing. Mostly studied in the retina, apoptosis is also extensively involved in the anterior segment, especially the ocular surface. Apoptosis of keratocytes is a rapid phenomenon following excimer refractive surgery. Any epithelial aggression stimulates a series of mechanisms leading to death of deep keratocytes. The role of epithelial cell mediators may explain the superiority of LASIK compared to PRK in terms of functional rehabilitation. Conjunctiva is also a major site in which inflammation and apoptosis are combined. Proinflammatory cytokines may both amplify immune reactions and stimulate epithelial apoptosis, which is most likely to result in elimination of injured tissues. Toxic drugs also play a major role and iatrogenic apoptosis should be avoided as much as possible, especially by eliminating preservatives from eyedrops, most of which use both proinflammatory and proapoptotic agents.
Laboratoire de Toxicologie, Faculté de Pharmacie, Université Paris V, France.
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Brignole
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Auzerie
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Baudouin
D017209:Apoptosis / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D005123:Eye / Q000166:cytology; D005128:Eye Diseases / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D009799:Ocular Physiological Phenomena; D013499:Surface Properties; D014945:Wound Healing / Q000502:physiology