TY - JOUR T1 - Local synthesis of sex hormones: are there consequences for the ocular surface and dry eye? JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 1596 LP - 1603 DO - 10.1136/bjophthalmol-2017-310610 VL - 101 IS - 12 AU - Emma J Gibson AU - Fiona Stapleton AU - James S Wolffsohn AU - Blanka Golebiowski Y1 - 2017/12/01 UR - http://bjo.bmj.com/content/101/12/1596.abstract N2 - Sex hormones are associated with the physiology and pathophysiology of almost all organs in the body, as well as most diseases. Interest in the associations between sex hormones and ocular tissues has increased in recent years. Androgens may have a positive effect on dry eye, whereas the effects of oestrogen on ocular conditions remain unclear. Intracrinology, the local synthesis and metabolism of hormones that is unique to humans, is of relevance to the eye and may help to explain why studies of the relationship between oestrogens and dry eye signs and symptoms are inconclusive. Knowledge of the pathways of hormone formation and metabolism is crucial to understanding the pathogenesis of ocular disease including dry eye. This review examines the mechanisms of steroidal sex hormone biosynthesis and reviews the significance of locally produced sex hormones, with a focus on ocular surface tissues. Much of the current literature is based on animal studies, which may not be transferable to humans due to the absence of intracrine production in animals. A large proportion of the human studies investigate systemic hormone levels rather than local levels. There is subsequently a need for additional studies to provide a better understanding of the local production of sex hormones within the human eye and ocular surface and to clarify the relationships between ocular levels of sex hormones and conditions including dry eye. ER -