Responses to tuberculin in the guinea-pig eye as a model of cell mediated immune responses in the external eye

Polyamine and histopathological changes after unilateral endotoxin-induced uveitis and its contralateral effects

The polyamines putrescine, spermidine and spermine are essential for normal cell function and proposed to be involved in inflammatory reactions. The polyamines were measured bilaterally in rabbit aqueous humor after unilateral endotoxin-induced uveitis. The contralateral eyes were injected with saline or not touched. Aqueous protein levels and leukocytes were determined and a histological evaluation was performed. Protein, leukocytes, putrescine and spermine increased in the treated eyes, but not in the untouched eyes. When saline was injected in the contralateral eye, a small increase in spermine was seen. Spermidine decreased first, but increased later, in both the endotoxin-injected and the other eye. Histopathologically, the treated eyes showed an infiltration of leukocytes, vasodilatation and in some cases optic nerve involvements. A mild reaction was also seen in the unchallenged contralateral eyes. The results show that polyamines might serve as a marker for acute inflammation in the eye and that the mechanism of putrescine and spermine induction is different from the one of spermidine. Polyamines are suggested to play a role in the cellular immune response.

Immunological responses in the eyelid and orbit

Immunological responses in the eyelid and the orbit are reviewed: (1) A local immune response is dependent on the presence of lymphoid tissue in an organ. Lymphoid tissue is found in the conjunctival fornices and in the lacrimal gland but not in the orbit. The eyelids also have lymphatic drainage into the local lymph nodes. A local immune response is found in the palpebral conjunctiva and in the lacrimal gland, measureable both as immunoglobulin or specific antibody levels in tears or as immunoglobulin producing cells within the tissue. No local immunity has been demonstrated in the orbit. (2) The other type of immune response found in the eyelids, the lacrimal gland and the orbit is the involvement of these tissues in systemic diseases. Systemic diseases with an immunological basis, which affect the above mentioned tissues are: atopic diseases of the skin, autoimmune diseases, immunodeficiency diseases and lymphoproliferative diseases. (3) Finally, it is possible that the extraocular muscles and the lacrimal gland have tissue specific antigens and therefore may be target tissues for organ specific autoimmune processes.