Nina is wearing her new sunglasses for dogs (Doggles). She looks cool and is now a babe magnet.
She has to wear them outside because she has Chronic Superficial Keratitis (Pannus), a progressive change occurs where blood vessels and scar tissue invade the cornea. Without her Doggles when out in the sun, and eye drops every two days, the disease will damage most or all of the corneal surface area resulting in blindness. It is believed that Pannus is an immune mediated disease. That is, some subcellular change has occurred in the cornea which the immune system then recognizes as abnormal resulting in an immune mediated attack in the cornea almost as if the cornea was foreign or transplanted tissue. The damage to the cornea which starts everything is thought to be associated with ultraviolet radiation. The first reports of cases of Pannus came from Austria and in the United States - from Colorado, both areas of higher elevation. Today, Pannus is diagnosed world wide, however it is well recognized that cases of pannus are more severe and harder to treat in areas of higher elevation, supporting the UV radiation theory. It is hypothesized that dissipation of the ozone layer has resulted in greater exposure to ultraviolet radiation.