Couching (ophthalmology)
Couching is the earliest documented form of cataract surgery. It involves dislodging the lens of the eye, thus removing the cloudiness caused by the cataract, resulting in aphakia. Couching was a precursor to modern cataract surgery and pars plana vitrectomy.
History
The Code of Hammurabi contains the earliest reference to the surgical procedure known as couching. The code also details the first recorded sliding scale for medical fees, linking the payment to a patient's wealth. A surgeon who successfully performed eye surgery with a bronze lancet would receive 10 silver shekels for a patrician, five for a plebeian, and two for a slave. This indicates that couching is one of the most ancient surgical procedures.The first reference to cataract and its surgical treatment in Europe are found in the writings of Chrysippus of Soli. The procedure was described in detail in the encyclopedia De Medicina, by the author Celsus.
The procedure was described in detail in the Indian medical treatise Sushruta Samhita, in the third volume, entitled the Uttara Tantra, which is attributed, in the traditions of both India and China, to a figure named Nagarjuna of the early Common Era. Evidence shows that couching was practiced in China, Europe and Africa. After the 19th century AD, with the development of modern cataract surgery, couching fell out of fashion over the next century, though it is still used in parts of Asia and Africa.
Couching was practiced in ancient India. The Sushruta Samhita's Uttaratantra section describes an operation in which a curved needle was used to push the opaque "phlegmatic matter" in the eye out of the way of vision. The eye would later be soaked with warm, clarified butter and then bandaged. Here is a translation from the original Sanskrit:
"At a time that is neither too hot or too cold, the patient who has been oiled and sweated is restrained and seated, looking symmetrically at his own nose. The wise physician should separate two white sections from the black part and from the outer corner of the eye. Then he should press properly into the eye, at the naturally occurring opening with a probe made of copper or iron, with a tip like a barley-corn, held by a steady hand with the middle finger, forefinger and thumb, the left one with the right hand and the other one contrariwise. When the piercing is done properly, there is the issue of a drop of liquid and a sound. The expert should moisten the exact place of piercing with a woman's breast-milk. Then he should scratch the circuit of the pupil with the tip of the probe. Without injuring, gently pushing the phlegm in the circuit of the pupil against the nose, he should remove it by means of sniffing."
Cataract couching began to gradually be replaced by cataract extraction after 1752, when Jacques Daviel of Paris presented his cataract extraction technique.