Couching is the earliest documented form of

cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble ...

surgery. As a cataract is a clouding in the lens of the eye, couching is a technique whereby the lens is dislodged, thus removing the opacity. Although couching is nowadays routinely practiced only in remote areas, it was a precursor to modern cataract surgery and pars plana vitrectomy.

History

Cataract surgery by “couching” (lens depression) is one of the oldest surgical procedures. The technique involves using a sharp instrument to push the cloudy lens to the bottom of the eye. Perhaps this procedure is that which is mentioned in the articles of the Code of Hammurabi (ca. 1792–1750 BC) though it is a mere speculation. Sushruta, an ancient Indian surgeon, described the procedure in “Sushruta Samhita, Uttar Tantra”, an Indian medical treatise (800 BC) (Duke-Elder, 1969; Chan, 2010). From then on the procedure was widespread throughout the world. Evidence shows that couching was widely practiced in China, Europe and Africa. After the 19th century AD, with the development of modern cataract surgery (Intra ocular extraction of lens (1748)), couching fell out of fashion, though it is still used in parts of Asia and Africa.

Modern use

Couching continues to be popular in some developing countries where modern surgery may be difficult to access or where the population may prefer to rely on traditional treatments. It is commonly practiced in Sub-Saharan Africa. In

Mali Mali (; ), officially the Republic of Mali,, , ff, 𞤈𞤫𞤲𞥆𞤣𞤢𞥄𞤲𞤣𞤭 𞤃𞤢𞥄𞤤𞤭, Renndaandi Maali, italics=no, ar, جمهورية مالي, Jumhūriyyāt Mālī is a landlocked country in West Africa. Mal ...

it remains more popular than modern cataract surgery, despite the fact that the cost of both methods is similar, but with much poorer outcome with couching. In

Burkina Faso Burkina Faso (, ; , ff, 𞤄𞤵𞤪𞤳𞤭𞤲𞤢 𞤊𞤢𞤧𞤮, italic=no) is a landlocked country in West Africa with an area of , bordered by Mali to the northwest, Niger to the northeast, Benin to the southeast, Togo and Ghana to ...

, a majority of patients were unaware of the causes of cataracts and believed it to be due to fate. It is not performed by ophthalmologists, but rather by local healers or "

witch doctor A witch doctor (also spelled witch-doctor) was originally a type of healer who treated ailments believed to be caused by witchcraft. The term is now more commonly used to refer to healers, particularly in regions which use traditional healing ...

s".

Technique

A sharp instrument, such as a thorn or needle, is used to pierce the eye either at the edge of the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

or the sclera, near the limbus. The opaque lens is pushed downwards, allowing light to enter the eye. Once the patients sees shapes or movement, the procedure is stopped. The patient is left without a lens ( aphakic), therefore requiring a powerful positive prescription lens to compensate.

Results

Couching is a largely unsuccessful technique with abysmal outcomes. A minority of patients may regain low or moderate visual acuity, but over 70% are left clinically blind with worse than 20/400 vision. A

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

n study showed other complications include

secondary glaucoma Secondary glaucoma is a collection of progressive optic nerve disorders associated with a rise in intraocular pressure (IOP) which results in the loss of vision. In clinical settings, it is defined as the occurrence of IOP above 21 mmHg requiring t ...

, hyphaema, and

optic atrophy Optic neuropathy is damage to the optic nerve from any cause. The optic nerve is a bundle of millions of fibers in the retina that sends visual signals to the brain. Damage and death of these nerve cells, or neurons, leads to characteristic featu ...

. Couching does not compare favourably to modern cataract surgery.

References

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