Environmental scanning electron microscopic study of macrophages associated with the tunica vasculosa lentis in the developing rat eye

Aims - To demonstrate the value of environmental scanning electron microscopy (ESEM) when used in combination with immunogold/silver enhancement methods as a valuable tool in ocular research, and to determine the phenotype of macrophages associated with the tunica vasculosa lentis while maintaining a topographical view of the lens surface. Methods - Prenatal and postnatal rat eyes were investigated by conventional scanning electron microscopy and ESEM. In the latter case tissues were prestained with a panel of antileucocyte monoclonal antibodies and visualised with colloidal gold conjugated secondary antibody followed by silver enhancement. Results - The preliminary data demonstrate that ED1⁺ ED2⁺ macrophages occur in large numbers around the lens and are associated with sectors of both normal vessels and those undergoing regression. Conclusion - The present study demonstrates that ESEM is an ideal way to combine scanning electron microscopy with immunohistochemistry and is therefore likely to have multiple other applications in ocular research.