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Our study 2 provided substantial ultrastructural and immunohistochemical evidence using lymphatic markers for the existence of early absorption lymphatic capillaries located on the external side of the fenestrated vessels of the choriocapillaris, an ideal juxtaposition for the recirculation of extracellular fluid, as well as being a strategic location for immunologic surveillance. The presence of the lymphatic-like system we described in the human choroid thus provides an anatomical basis for antigen presentation in the posterior segment of the eye, as well as a pathway from the eye to the sentinel lymph nodes, similar to that described for the anterior uveal lymphatic vessels. 3

Schroedl et al. 4 proposed in their original consensus statement on the immunohistochemical detection of ocular lymphatic vessels that “the use of markers in ultrastructural analysis is recommended (except for ocular regions where existence of lymphatics is well established as in conjunctiva and inflamed cornea).” Further, Heindl et al. 1 commented on our study of the developing and adult human choroid 2 that “despite possible postmortem tissue alterations, numerous previous studies successfully applied different detection systems for ultrastructural investigations using ocular human donor tissue.” However, a recent paper from this group of authors investigating lymphatics in the human iris and ciliary body 5 does not provide ultrastructural evidence, let alone immunogold transmission electron microscopy (TEM), to support their conclusion that “various structures in the anterior uvea were immunoreactive for several lymphatic markers, while a classical lymphatic system was not …