Issue: November 2020
Source/Disclosures
Disclosures: Agarwal reports no relevant financial disclosures.
May 06, 2019
3 min read
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Management method addresses couching complications

The ancient cataract removal procedure is still used in some parts of the world.

Issue: November 2020
Source/Disclosures
Disclosures: Agarwal reports no relevant financial disclosures.
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Cataract surgery by “couching” is one of the oldest surgical procedures, first described by Maharshi Sushruta, an ancient Indian surgeon, and later adopted by the Greeks, the Romans as well as the Egyptians, Arabs and Europeans.

Couching was typically performed on mature cataracts. The technique involved using a sharp instrument, such as a thorn or needle, to pierce the eye at the limbus. The opaque lens was then dislocated from the central visual axis and pushed down into the vitreous cavity through the pars plana. The cataract thus remained in the eye but was no longer blocking light, producing an instantaneous improvement in vision. In fact, this was the only method of cataract treatment until the 19th century (Figure 1).

Couching in the present era

Couching
Figure 1. Couching. Needle is pierced through the sclera (a). Rocking movements are done to break the zonules (b). The cataractous lens is dislocated (c). The visual axis is clear (d).

Source: Amar Agarwal, MS, FRCS, FRCOphth

Cataract surgery has come a long way since then with pivotal discoveries during the last 60 years. But couching is still not a thing of the past, and much to our disbelief, it is still being practiced in certain countries.

Couching camps are quite the norm, and patients with visual disability assemble on a particular day of the week at these sites for the surgery. After a brief history and a crude check for visual acuity, the coucher selects his patients for surgery. The patient is led into an apparent operation theater room. With just a piece of carpet on the floor for more religious reasons than for asepsis, the OR room appears to be primitive and rustic.

Couching technique
Figure 2. Couching technique. The needle is the instrument that performs couching (a). The couching needle is passed about 4 mm from the limbus to break the zonules and dislodge the cataract (b).

The coucher then reveals his magic weapon: a pen sort of instrument, which when uncapped shows a needle that appears to be almost blunt. Without any preparation or anesthesia, he begins his surgery by stabilizing the eye with his thumb. The needle is injected perpendicular into the eye, almost 3 mm to 4 mm behind the limbus, and gradually pushed forward with a rotating movement (Figure 2). With sweeping movements, the whole lens is dislodged into the vitreous cavity. It is also swept up and down several times to ensure the cataract will not rise up again.

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Complications of couching
Figure 3. Complications of couching. The needle is passed inside the eye to break the zonules (a). The needle can create a tear in the retina, leading to retinal detachment (b).

An immediate postoperative functional visual examination is then done to see if the patient is able to count fingers. With some grime and hot water, the needle gets sterilized for the next patient.

Complications of couching

Glued IOL scaffold for couching cases
Figure 4. Glued IOL scaffold for couching cases. After vitrectomy, the subluxated cataract is brought above the iris with the PAL technique and a glued IOL is implanted. The glued IOL acts as a scaffold, and the phaco probe can emulsify the cataract without fear of the cataract falling down (a). Phaco completed. Note the glued IOL behind (b). Vitrectomy done (c). Single-pass four-throw pupilloplasty performed if needed for optic capture or traumatic mydriasis (d).

Couching is a largely unsuccessful technique with abysmal outcomes. The retained cataractous lens and the lack of aseptic technique have deleterious effects on the eye, often resulting in blindness shortly after the procedure. Other complications such as corneal edema, iritis, secondary glaucoma and optic atrophy, vitreous hemorrhage, cystoid macular edema, retinal detachment (Figure 3), and the more dreadful endophthalmitis and phthisis have also been reported. Because the patient is left aphakic, a powerful positive prescription lens is required to compensate.

Clinical examination

We examined five consecutive new cases of couched eyes that presented to our hospital in Nigeria. After a thorough history, the patients underwent a detailed slit lamp and indirect ophthalmoscopic examination. The cataracts were found to be dangling in the vitreous cavity partially supported by the zonules. One of the five patients also had a retinal detachment. The findings were further documented by an ultrasound B-scan.

Management

Due to deficient capsular support, a cataractous lens extraction with a secondary IOL procedure using the glued IOL technique was planned for each of them. This involves scleral flap making and covering the part of the externalized haptic by the scleral flaps, then sealed with fibrin glue. With adequate and appropriate haptic tuck, glued IOL imparts a stable IOL fixation and is a secured method of secondary IOL placement.

Another way to manage these cases is to first do a glued IOL after bringing the cataract lens anteriorly with the posterior assisted levitation (PAL) technique. This is followed by phaco of the cataract as the glued IOL works like a scaffold This is the glued IOL scaffold technique (Figure 4).