PHYSIOLOGICAL-MECHANISMS FOR THE PROTECTI ON OF THE EYE

The physiological mechanisms for the protection of the eye are only pa rtly known. It becomes increasingly evident that the eye is supervised by and included in the immune system of the body. The physiological p rotection system of the eye consists of a mechanical and an immunologi cal component. The lacrimal gland plays a key role for the immune syst em of the anterior segment. It is part of the MALT system, and the cha racterisation of the special ocular components of this system - includ ing possible homing receptors - will give important informations. Rese arch of the ocular immune system has disclosed various special feature s, like the anterior chamber associated immune deviation (ACAID). The distribution of antigen presenting cells and its localization, but als o the distribution of T-and B-lymphocytes is an important factor for l imiting ocular inflammation. The phenomenon of 'apoptosis' seems to ha ve an important role in maintenance of the ACAID, The cornea is nearly free of cells, and infiltrating antigen presenting cells may prevent ACAID. Research regarding mechanisms which are used to tune these vari ous cells will give answers to the questions how the cornea contains i ts optical transparency, how corneal transplant rejection works, how t he eye participates in systemic disorders and may also define the role of a possible dysfunction of antigen presenting cells of the retinal pigment epithelium in senile maculopathy.