BLOOD-OCULAR BARRIER BREAKDOWN IN EYES WITH OCULAR MELANOMA - A POTENTIAL ROLE FOR VASCULAR ENDOTHELIAL GROWTH-FACTOR VASCULAR-PERMEABILITYFACTOR

A series of 130 eyes with ocular melanomas, 19 normal eyes, and 18 eye s affected with other disorders leading to blood-ocular barrier (BOB) breakdown were immunohistochemically stained for albumin to localize s ites of BOB failure within the retina, ciliary body, and iris. Thirty- nine of the eyes containing melanomas and all of the other eyes were a lso immunohistochemicallly stained for vascular endothelial growth fac tor (VEGF), to investigate its potential role as a mediator for BOB fa ilure. Eyes with melanomas showed widespread leakage through the retin al pigment epithelium, and 58% demonstrated leakage from retinal vesse ls in the proximity of the tumor. BOB failure remote from the tumor al so occurred in retina (50%), optic nerve head (77%), ciliary body (51% ), and iris (51%), suggesting that a soluble mediator may be involved. VEGF was demonstrated intraretinally in the proximity of (46%) and re mote from (24%) melanomas and in eyes affected by other disease proces ses, particularly those involving neoplasia or retinal detachments, us ually, within particular cell populations (ie, retinal vessel walls, g anglion cells, inner or outer nuclear layers, retinal pigment epitheli um). VEGF localization in retina, ciliary body, and iris often coincid ed with sites of extravasated albumin. Preincubation of albumin or VEG F antibodies with normal serum or VEGF peptide, respectively, eliminat ed or markedly reduced all immunoreactivity. Only 1 of 14 normal postm ortem eyes and 0 of 5 normal surgically, removed eyes showed VEGF posi tivity in the retina, 5 of 19 normal eyes had weak positivity in the c iliary body, and VEGF was not demonstrated in the iris of normal eyes. VEGF cannot account for all of the BOB failure associated with ocular melanomas, but appears likely to play a contributing role in many cas es.