IMMUNOHISTOLOGICAL STAINING OF THE VITREO US

Background: Immunohistological staining of the vitreous is difficult b ecause of its high water content. We present a method for immunohistol ogical staining of celloidin-embedded eyes. Results from diabetic and nondiabetic eyes are demonstrated. Method: Diabetic and non-diabetic e yes were firstly immersed in formol and then slowly dehydrated using r ising concentrations of glycerine (sink method). Subsequently, the who le globe was embedded in celloidin and cut into 200-mu m sections. Con trol areas of interest were dissected from the 200 mu m sections under a lightmicroscope. These specimens were then embedded in paraffin and cut into 7-mu m sections. The 7-mu m sections were immunohistochemica lly stained for type I-collagen, type IV-collagen, fibronectin and lam inin. Results: This method makes immunohistochemical staining of the v itreous possible. Type IV collagen, laminin and fibronection were foun d at higher concentrations in diabetic eyes than in normal eyes. Type I collagen was detected in neither diabetic nor in normal eyes. Conclu sions: Our method of examination allows immunohistological staining of the vitreous in its place of origin. Although our method is time cons uming, it has some advantages over biochemical analysis: Even minimal changes and their exact distribution can be detected. Our first result s show that the vitreous is built up inhomogeneously and that patholog ical influence can cause structural changes.