Retinal compartment

The neurosensory retina is an immune privileged tissue situated in a highly protected compartment with multiple defense lines (Figure 24.3). Like brain neurons, the retinal neurons... 

Vitreous fluorophotometry is a noninvasive quantitative method for measuring small amounts of fluorescein in various ocular compartments, including assessment of the blood-retinal barrier. Both slit-lamp-based and objective scanning fluorometers have been used to characterize the fluorescence of the vitreous in health and disease. 

A compartment syndrome model has been proposed to explain the development of CRVO. According to this model, an unyielding scleral ring at the optic disk forms the boundary of the compartment. Thrombosis of the central retinal vein may occur when vascular thickening or collagen changes in the scleral ring allow increased pressure on the central retinal vein within a confined space. 

The targets of photooxidative reactions may be proteins, lipids, DNA, RNA, and/or cell membranes (Straight and Spikes, 1985). In vitro tests can be designed to determine the specific sites of damage to the various ocular compartments (i.e., lens and retinal epithelial cells and photoreceptor cells) and the products of those reactions. Table 11.2 presents a summary of additional biochemical and photophysical techniques that can be performed to predict the potential for and extent of in vivo phototoxicity more accurately. 

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