Retinoic acid cornea

Systemic treatment of 13-cis retinoic acid frequently leads to cheilitis and eye irritations (e.g., unspecific cornea inflammation). Also other symptoms such as headache, pruritus, alopecia, pains of joints and bone, and exostosis formation have been reported. Notably, an increase of very low density lipoproteins and triglycerides accompanied by a decrease of the high density lipoproteins has been reported in 10-20% of treated patients. Transiently, liver function markers can increase during oral retinoid therapy. Etretinate causes the side effects of 13-cis retinoid acid at lower doses. In addition to this, generalized edema and centrilobulary toxic liver cell necrosis have been observed. 

An analogue of vitamin A, isotretinoin (Accutane), or 13-c/s-retinoic acid, is used for control of severe recalcitrant cystic acne and other keratinizing dermatoses (also see Isotretinoin under Drugs Affecting the Cornea and Lens, above). 

Two retinoids, retinoic acid and retinal, appear to have most of the biochemical functions attributed to vitamin A Retinoic acid is required for cell differentiation and is the ligand for two families of nuclear receptors, RAR . y and RXR 0 y. These receptors are part of a family of superreceptors that include the steroid hormones and cholecalciferol. Vitamin A deficiency can lead to a variety of symptoms depending on the age of the deficient person. The most serious syndrome is keratomalacia, which results in desiccation, ulceration, and xerophthalmia of the cornea and conjunctiva. It is one of the leading causes of blindness in infants and children. 

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