Viral disease
Ocular viral infections are a particularly complex topic for diagnosticians and clinicians alike. The eye’s component parts, though packed into a space measuring approximately one inch in diameter, are rich in diversity and varied in embryonic origin, inviting infection by viruses with a wide range of tissue tropisms. Some of the eye’s compartments have evolved mechanisms of immune privilege; while offering potential protection against injurious effects of inflammation on the transparency of the eye’s optical path, these mechanisms may alter the immune response to pathogens, including viruses. The anterior segment of the eye is separated from the external world by only a thin mucous membrane, providing ready access for a panoply of viral carriers, including airborne particulate matter, purposely introduced foreign bodies such as contact lenses, and the occasional errant finger. Blood vessels and the optic nerve provide alternative portals for virus entry.
