Permeability of iridial blood vessels

Ocular Pharmacokinetics

“…Electron-dense markers injected intravenously are held within the vessel lumen, but solutes of small molecular weight can probably escape between the cells (CUNHA-VAZ et al 1966;BELLHORN 1980). The rate at which the transfer occurs depends on species and age (SZALAY et al 1975) as well as the molecular size of the solute. Dyes are used for these observations, and their passage could be missed because of dilution in the stromal fluid and aqueous humor.…”

Effect of Topical Chemical Irritation on the Blood-Aqueous Barrier of the Rat Eye

“…In the present study the analysis of the epithelial barrier could not be done using the present tech nique. However, based on the previous study in the rat, the ciliary body seems to play only a minor role in the breakdown of the bloodaqueous barrier [Szalay et al, 1975].…”

“…In our preliminary experiments, irritation of the rat eye with 5% formaldehyde did not enhance the response in comparison to re sponse obtained with a 1% solution. A 5% solution has been shown to cause an unspe cific irritation in the rabbit eye [Butler ct al., 1979], No age-related differences were ob served in responses to neural irritation, such as have been observed after paracentesis in the rat [Szalay et al, 1975], Histologically, the breakdown of the blood-aqueous barrier was demonstrated in the iris vessels of the rat. In the rabbit some leakage of fluorescein from the iris vessels has previously been shown after chemical irritation [Uusitalo, 1984], although the main site of the disruption of the bloodaqueous barrier seems to be the ciliary pro cesses [Butler et al, 1979].…”

Ultrastructure of the iris

“…These vessels are, for example, impermeable to intravenously injected horseradish peroxidase ( Fig. 20; Freddo and Raviola, 1982a;Szalay et al, 1975;Vegge, 1971). …”