The story of EDTA chelation

Published: June 15, 2020

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The story of EDTA chelation – a common procedure in ophthalmic practices – begins in Switzerland in 1892, with a brilliant young man presenting a revolutionary theory for his doctoral dissertation in chemistry. At 24, Alfred Werner described the idea of “coordination compounds,” now called chelates. The word chelate comes from the Greek word for claw. Werner’s theory explained how some organic molecules, almost like claws, bind to metals. In 1913, Werner was awarded the Nobel Prize in Chemistry.

 

The first application to come out of Werner’s work was in the 1930s, when EDTA (ethylene diamine-tetra-acetic acid) was synthesized in a German laboratory and used as a chelating agent to treat heavy metal contamination in workers who had been exposed to lead paint. Administered via IV, EDTA binds to metals, creating a compound that is then excreted through urine. EDTA chelation was later used as an antidote for poison gas. In the 1950s, chelation therapy was used by the US Navy to treat workers who had developed iron overload after painting old warships.

 

So, how do we get to ophthalmology? It has to do with the metal calcium. The disorder of band keratopathy is characterized by calcium deposits across the cornea, resulting in blurred vision, irritation, and the sense of sand in the eye. For previous generations, the treatment was to mechanically debride the eye of the calcium. In 1952, Dr. W. M. Grant wrote an article in Archives of Ophthalmology describing his new work using EDTA chelation to remove calcium from corneas. Dr. Goodwin Breinin and Dr. A. Gerard DeVoe expanded on Grant’s work, and two years later wrote in the Archives of Ophthalmology that Grant’s technique was rapid, simple, and highly effective, adding, “It should be the primary treatment in cases of band keratopathy and may make future corneal surgery unnecessary.”

 

For organizations requiring EDTA for ophthalmic procedures, Edge Pharma produces two concentrations: 1.5 percent and 3 percent.

 


References

Eckes, E. MSN, Clinical Nurse Specialist, Journal of Infusion Nursing, Chelation Therapy for Iron Overload: Nursing Practice Implications https://www.ncbi.nlm.nih.gov/

Online article, Nobel Prize website, “The Nobel Prize in Chemistry 1913 was awarded to Alfred Werner "in recognition of his work on the linkage of atoms in molecules by which he has thrown new light on earlier investigations and opened up new fields of research especially in inorganic chemistry."