You should look at the Normal Retina photo first for comparison. The angioid streaks are the gray lines emanating from the optic disk which resemble cracks in dried mud. These cracks provide access for abnormal blood vessels originating from the choroid to grow under the retina. The subtle hemorrhage near the center of the picture is evidence of such an event in this eye. The most common cause for these streaks is pseudoxanthoma elasticum, a genetic disease of elastin fibers. Pseudoxanthoma elasticum is caused in 80% of cases by one of several mutations of the ABCC6 gene on chromosome 6.