The eyes of albino animals appear red because the colour of the red blood cells in the retina can be seen through the iris, which has no pigment to obscure this. Some albino animals may have pale-blue eyes due to other colour generating processes. Albino vertebrates exposed to intense light typically lose photoreceptors due to apoptosis. In all albino mammals studied, the centre of the retina is under-developed and there is a deficit of rod cells; the central ganglion cell density is approximately 25% below normal (except for the gray squirrel). In nearly all mammals, the overwhelming majority of photoreceptors are rods rather than cones. Albinism specifically affects the rod cells, but the number and distribution of the cones is unaffected. In contrast, the retinas of birds are cone rich meaning that the vision of albino birds is affected less than albino mammals. Reduced protection from sunlight in albino creatures
Melanin protects the skin from ultra-violet radiation in sunlight. Melanosomes block harmful electromagnetic radiation from the sun while allowing beneficial frequencies to enter the body. This means some animals may die from UV radiation due to a lack of protection. Albino humans must use an excessive amount of sunscreen, even if the sun is hidden behind the clouds.
On physical examination, a palpable and pulsatile abdominal mass can be noted. Bruits can be present in case of renal or visceral arterial stenosis.The signs and symptoms of a ruptured AAA may include severe pain in the lower back, flank, abdomen or groin. A mass that pulses with the heart beat may also be felt. The bleeding can lead to a hypovolemic shock with low blood pressure and a fast heart rate, which may cause fainting. The mortality of AAA rupture is as high as 90 percent. 65 to 75 percent of patients die before they arrive at the hospital and up to 90 percent die before they reach the operating room. The bleeding can be retroperitoneal or into the abdominal cavity. Rupture can also create a connection between the aorta and intestine or inferior vena cava. Flank ecchymosis (appearance of a bruise) is a sign of retroperitoneal bleeding and is also called Grey Turners sign. Causes
The exact causes of the degenerative process remain unclear. There are, however, some hypotheses and well-defined risk factors. Tobacco smoking: More than 90% of people who develop an AAA have smoked at some point in their lives. Alcohol and hypertension: The inflammation caused by prolonged use of alcohol and hypertensive effects from abdominal edema which leads to hemorrhoids, esophageal varices, and other conditions, is also considered a long-term cause of AAA. Genetic influences: The influence of genetic factors is high. AAA is four to six times more common in male siblings of known patients, with a risk of 20–30%.