CD34 and age-related macular degeneration: In a previous screen of endothelial cell adhesion markers in eyes with AMD, we noted that some capillaries that were reactive with the lectin Ulex europaeus agglutinin-I (UEA-I), previously used as a marker of viable endothelial cells [11], did not exhibit immunoreactivity with antibodies directed against CD34, a cell surface glycoprotein expressed on vascular endothelial cells.