Purpose
To assess iris angiogenesis using human explants and determine the role of hypoxia during iris neovascularization.
Methods
Human irises were isolated post‐mortem from human research consented donnors. Explants were seeded onto extracellular matrix (ECM), and kept at normal oxygen concentrations (normoxia, 20% O2) or exposed to hypoxia (1% O2) in standard tissue culture conditions for 48 h. Iris angiogenesis was analyzed by quantifying the neovascular area. Furthermore, iris neovascular structures were characterized by immunofluorescence.
Results
Human iris ex vivo neoangiogenesis could be observed within 48 h after the explants were seeded onto ECM, and was defined as vascular sprouts and/or tufts. Vascular sprouts were more common in normoxia, while vascular tufts were mostly formed in hypoxia. A significant increase in vascular area was observed in irises exposed to hypoxia when compared to normoxia. Positive immunoreactivity to specific endothelial cell markers confirmed human iris neoangiogenesis ex vivo.
Conclusions
Our data shows the first human ex vivo neoangiogenesis assay, using iris. The method here presented could have potential use in testing pro‐ and anti‐angiogenic drugs in an human ocular context.