Purpose
To investigate corneal neovascular complexes (CoNV) in vivo for the presence of lymphatic vessels.
Methods
Patients with clinically recognizable corneal neovascularisation (CoNV) undergoing corneal angiography for fine needle diathermy were included. Each CoNV complex was imaged using slit lamp biomicroscopic photography, confocal, and fluorescein and indocyanine green angiography (FA and ICGA). Fluorescein dye leakage and uptake from the extravascular to the intravascular space was investigated determined using repeat angiography and subtraction analysis. Vessel parameters (area, diameter, branching, tortousity, flow) were analysed using in house software.
Results
11 patients, (7 males and 4 females, mean age 68 years; range 22 - 74 years) were included. Only vessels containing red blood cells were visible using colour or red free images. Additional vessels not containing cells were detected using confocal and angiography (mean diameter 10-20mm); often adjacent to larger venules.
Conclusions
Not all vessels in the cornea carry or only intermittently carry red blood cells. Imaging of CoNV complexes using confocal and angiography allowed the differentiation between vessels with red blood and other cell trafficking, and vessels with acellular flow. It is unclear whether these latter ‘plasma’ vessels are dual functional and serve as lymphatic type vessels. These vessels may be of importance in mediating inflammation and rejection.