Absence of lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices

Abstract

Purpose. To evaluate the presence and appearance of blood and lymphatic vessels in nonfunctioning bleb capsules of glaucoma drainage devices (GDD). Materials and methods. Non-functioning (n=14) GDD-bleb capsules of 12 patients were analyzed by immunohistochemistry for blood vessels (CD31, vascular endothelium), lymphatic vessels (lymphatic vessel endothelial hyaluronan receptor-1 [LYVE-1] and podoplanin) and macrophages (CD68). Results. CD31+++ blood vessels and CD68+ macrophages were detected in the outer layer of all specimens. LYVE-1 immunoreactivity was registered in single non-endothelial cells in 8 out of 14 (57%) bleb capsule specimens. Podoplanin-immunoreactivity was detected in all cases, located in cells and profiles of the collagen tissue network of the outer and/or the inner capsule layer. However, a colocalization of LYVE-1 and podoplanin as evidence for lymphatic vessels was not detected. Conclusions. We demonstrate the presence of bloodvessels but absence of lymphatic vessels in nonfunctioning bleb capsules after GDD-implantation. While the absence of lymphatic vessels might indicate a possible reason for drainage device failure, this needs to be confirmed in upcoming studies, including animal experiments.