Choroidal vasculature

Sodium fluorescein is a pharmacologically inert component of resorcinolphthalein. Its fluorescent characteristics allow its electrons to be stimulated by blue light (465 to 490 nm) and then to decay, emitting yellow-green light (520 to 530 nm). In the eye fluorescein is confined to the retinal and choroidal vasculature, which is seen in stark contrast to the surrounding nonfluorescent structures. 

Water transport from the vasculature into the ventricle is facilitated by aquaporin-1 (AQPl) highly expressed in the apical (ventricular-facing) membrane of the choroid plexus, and via AQP4 in the ependymal lining of the ventricles (Zador et al., 2007). Deletion of AQPl reduces by fivefold osmotically induced water transport in the choroid plexus (Oshio et al., 2005). CSF production is significantly reduced in AQPl-deficient mice, but only by 20-25%, indicating a substantial contribution of extrachoroidal fluid production by the brain parenchyma (Zador et al.,... 

Conventional fluorescein angiography has been a very useful clinical tool to assess the ocular vasculature. However, it has a number of limitations. First, the dye rapidly fills both the retinal and choroidal vessels thus, the visualization of small vascular beds, such as CNV, is often obscured by the lack of contrast caused by the bright fluorescence emanating from the large volume of dye present in the... 

BPD-MA is an example of a porphyrin, which in pre-clinical studies was shown to target the tumor vasculature. Intra-ocular tumors implanted in rabbit eyes were used as a model for neovasculature and the very efficient destruction of these tumors could be attributed primarily to the destruction of the tumor vasculature. The established choroidal vessels remained largely intact [61,161]. Based on these studies, this compound has been developed by QLT Phototherapeutics and Ciba-Vision as a first line treatment for age-related macular degenerateion (AMD) of the eye [162-166]. In 1999, approval for PDT using BPD-MA in the treatment of AMD was obtained in Switzerland and more recently in Canada, the USA and several other European countries. It is anticipated that the development of this agent or its analogues for oncological indications will be resumed. 

---