Upward vs. downward lens dislocations!
A dislocated lens (ectopic lens) is a lens that has moved out of position because some or all of the supporting ligaments have broken. Some people are born with conditions that can cause weak ligaments and are prone to having a dislocated lens.For example, about half of the patients with Marfan syndrome, in which there is a defect in fibrillin gene and normal connective tissue function is disrupted, develop upward dislocated lenses (the top photo), as well as tall stature, long fingers and tendency toward aortic wall ruptures. A downward dislocated lens (bottom photo) is very typical for a condition called Homocystinuria. Homocystinuria is an inherited disorder that affects the metabolism of the amino acid methionine, resulting in the accumulation of homocystine. It is associated with cardiovascular disease, deep vein thrombosis, thromboembolism, and stroke. Mental retardation and ectopic lens do occur too.