gms | German Medical Science

Patients with diabetes mellitus have an increased frequency of dry-eye symptoms. The morphological changes of "diabetic conjunctiva" include squamous metaplasia and goblet cell loss; these alterations are reported to correlate with the blood-sugar levels and the severity of peripheral polyneuropathy. Furthermore, changes of the conjunctival microcirculation of diabetic patients have been described. Latest reports suggest that the pathogenesis of the above-mentioned alterations is an immunomodulatory inflammatory one, possibly initiated by autoantigens, which are localized in the lacrimal gland or in the layers of the ocular surface.

In the proposed research project, conjunctival biopsies of patients with diabetes mellitus will be compared with a non-diabetic control group. These biopsies will be obtained on opening of the conjunctiva during standard pars plana vitrectomies. These specimens will be fixed in formalin, and examined using both conventional histological and immunohistological methods. These investigations will aim at characterizing the lymphocytic populations (CD4 versus CD8), possibly with demonstration of the transcription factor T-bet in the T- and/or B-cell populations. Further the expression of the B-cell antigen BAFF in the cellular infiltrates will be analysed. The aim of the examinations is determine if there is any correlation between the density of the inflammtion, and the presence of- and degree of dry eye symptoms in diabetic patients.