IELTS Academic Reading Practice Test 389

The oldest operation for cataract — the clouding of the lens that remains the commonest cause of blindness worldwide — was not an operation of removal at all. Known in English as couching, it involved passing a sharp needle into the eye and pushing the clouded lens downwards, out of the line of sight, where it stayed for the rest of the patient's life. The technique is thousands of years old, it required no hospital and no equipment beyond a needle, and in much of the world it was the only treatment for cataract until remarkably recently.

The earliest detailed account appears in the Sushruta Samhita, a Sanskrit medical compilation whose date is still disputed but which is generally placed in the middle of the first millennium BCE. Its authors described the cataract as a disorder of the humours of the eye and recommended a curved needle, held between thumb and forefinger and steadied with the other hand, to displace the opacity. The text is strikingly practical. It lists the signs that a cataract is ready to be treated, warns against operating on an inflamed eye, and instructs the surgeon to bandage the eye afterwards.

Knowledge of the procedure appears in the Mediterranean world as well. Aulus Cornelius Celsus, a Roman encyclopaedist of the first century CE, set out a version of it in his treatise On Medicine, describing how a needle should be introduced until it reached the lens and then used to press the lens down. Celsus was not a practising physician and much of his writing was compiled from Greek sources, which suggests that Greek surgeons already knew the technique. The word cataract itself derives from a Greek term for a waterfall.

In practice the operation was brutally simple, and its simplicity explains its endurance. The patient sat on a low stool or lay on the ground, often held steady by assistants. The operator, who might be a trained physician but might equally be an itinerant craftsman, steadied the eye with one hand and drove a needle — sometimes a stout thorn or a piece of copper — through the outer coat of the eye just behind the coloured iris. If all went well, the lens dropped back into the jelly of the eye, and the patient could at once make out light, shapes and movement. There was no anaesthetic beyond, perhaps, a cold compress.

Arabic-speaking physicians took up the operation and refined it. In the tenth century Ammar ibn Ali al-Mawsili, working in what is now Iraq, described a different approach: a hollow needle through which the softened lens could be drawn out of the eye by suction. His account is the earliest known description of cataract extraction, and it shows that some practitioners were already dissatisfied with pushing the lens aside. Ammar's method demanded great skill and did not replace couching, which remained standard for centuries.

In medieval and early modern Europe, couching was largely the trade of travelling oculists, who moved from town to town, operated in public and charged a fee. Some were respected; others were little better than showmen. The operation was painful and dangerous, and its results were unpredictable. Because the displaced lens stayed inside the eye, it could provoke inflammation, bleeding or a rise in pressure, and some patients lost the eye altogether. Couching was therefore usually a last resort, attempted when the patient was already blind.

The dominance of couching ended in the eighteenth century. Building on earlier, less successful attempts by others, the French surgeon Jacques Daviel began in the 1740s to open the eye and remove the clouded lens entirely, and he described the method in print some years later. Extraction gave better sight than couching and, in skilled hands, fewer complications. It spread slowly, because it demanded far more of the surgeon, but during the nineteenth century it displaced couching in European hospitals.

Yet couching did not disappear. It survived among poor patients and in remote rural areas, and outside Europe it continued wherever there was no one able to perform extraction. Its advantages were real: it needed no operating theatre, no trained assistant, no stitches and almost no equipment. For a patient a day's walk from the nearest doctor, a needle and a steady hand were better than nothing.

Better than nothing is not the same as safe. Medical journals have continued to publish reports of couching carried out by traditional practitioners in parts of West Africa and South Asia, sometimes on people who had not been told what the procedure involved. In such cases the eye often remains inflamed, the lens may swell and cause a painful rise in pressure, and vision can end up worse than before. Repairing the damage is difficult and not always successful. For many people, the choice is not between good treatment and bad, but between bad treatment and none.

Modern cataract surgery is, in a sense, the exact opposite of couching. The clouded lens is broken up with ultrasound, drawn out through a tiny incision and replaced with an artificial lens; the first such implant was inserted by the British ophthalmologist Harold Ridley in 1949, and the technique of fragmenting the lens with ultrasound was developed by Charles Kelman in the 1960s. The operation is now among the most frequently performed in the world. What has been abandoned is not the ambition of the ancient surgeons but their method.

Touch is the first sense to develop in the womb and among the last to fade, and it is the one we find hardest to do without. Yet it is not a single sense at all. The skin of an adult covers some two square metres and contains several distinct populations of nerve endings, each tuned to a different aspect of mechanical contact. What we experience as a single impression — the smoothness of a table, the warmth of a hand — is assembled in the brain from several streams of data.

In hairless skin, such as the fingertips, the lips and the soles of the feet, four kinds of mechanoreceptor have been identified. Merkel cells, sitting close to the surface, respond to steady pressure and are thought to be important for detecting edges and fine detail. Meissner corpuscles, just beneath them, are wrapped in layers of tissue and fire only when a stimulus changes, which suits them to detecting the first contact and the faint flutter of a moving object. Ruffini endings, deeper still, signal that the skin is being stretched. Pacinian corpuscles, the largest and deepest, are tuned to high-frequency vibration and can register a tap transmitted through a table.

The density of these receptors varies enormously across the body. A fingertip contains hundreds of them per square centimetre; the skin of the back contains very few. The consequence can be shown with two pencil points: on the fingertip they are felt as two separate touches when they are only a few millimetres apart, while on the back they may have to be several centimetres apart before the subject notices two. This unevenness is reflected in the brain. When the Canadian neurosurgeon Wilder Penfield stimulated the surface of the brain in awake patients during surgery in the mid-twentieth century, he found a map of the body in which the lips and hands occupied an area out of all proportion to their size.

Signals from the skin travel along nerve fibres that are among the fastest in the body, thickly insulated with myelin and capable of conducting impulses at tens of metres per second. They enter the spinal cord and ascend towards the brain. On the way they cross over in the brainstem, so that signals from the left hand are handled by the right hemisphere. They then reach the thalamus, a relay station deep in the brain, and pass to a strip of cortex at the top of the parietal lobe, where the map Penfield described is laid out. Damage to this region leaves people unable to identify an object by feel, even though they can still grip it.

How a mechanical force becomes a nerve impulse was for a long time obscure. Part of the answer is a family of ion channels called Piezo proteins. Piezo2, discovered in 2010 by a team led by Ardem Patapoutian, sits in the membrane of touch-sensitive cells and opens when the membrane is distorted, allowing charged particles to flood in and set off an electrical signal. Mice engineered to lack Piezo2 in their sensory neurons are strikingly insensitive to gentle touch. Patapoutian shared the 2021 Nobel Prize in Physiology or Medicine for this work.

Touch is rarely passive. We run a finger over a surface rather than waiting for the surface to touch us, and this active exploration changes what the brain receives. Movement generates a continuous stream of changing signals, and the brain appears to damp down the predictable consequences of our own actions so that unexpected features stand out. Experiments in which participants judge the roughness of materials show that they tend to do better when allowed to move their fingers than when a machine moves the material across a stationary hand.

A second, slower system seems to serve a different purpose. In the 1990s, researchers identified a class of unmyelinated nerve fibres in hairy skin that respond best to slow, gentle stroking at a few centimetres per second — roughly the speed at which a hand moves when it strokes an arm. These C-tactile fibres conduct signals very slowly and project not to the somatosensory cortex but to the insula, a region associated with bodily awareness and emotion. Work with a patient who had lost the large touch fibres showed that she could still perceive the pleasantness of a gentle stroke, even though she could not say precisely where it had landed.

Many questions remain open. It is still debated whether the pleasantness signalled by C-tactile fibres is an innate property of the nervous system or a learned association with affectionate contact, and their contribution to social bonding is difficult to measure. The status of Merkel cells has also been contested: they are not neurons but modified skin cells, and for years it was unclear whether they sense deformation themselves or merely pass on signals from the nerve endings beside them. Recent evidence favours the first explanation.

One thing is clear: touch fades with age. The number of Meissner corpuscles in the fingertips falls steadily from early adulthood, and older people are slower to detect a light touch and less accurate at telling two points apart. The loss is rarely total, and it is often unnoticed until it interferes with tasks such as buttoning a shirt. Because touch is so rarely tested in clinics, its decline is seldom recorded.

An eighty-year-old with a chest infection who would once have been admitted to a hospital ward can now be treated in her own bedroom. A nurse visits once or twice a day to give intravenous antibiotics, a doctor reviews her by video link, and a monitor by her bed relays her oxygen levels to a team watching for signs of deterioration. Schemes of this kind, known variously as hospital at home, early supported discharge or virtual wards, have multiplied over the past two decades in Australia, Canada, the United States and Europe. They raise a question that is increasingly answered by budgets rather than by argument: how much of what hospitals do should be done at home?

The case for moving care into the home is substantial. For a selected group of patients, reviews that combine the results of trials have generally found that recovery at home is no worse than recovery on a ward, and that costs are lower. Hospital brings hazards of its own. Infection spreads between patients, sleep is broken by noise and by being woken for observations, and older people, particularly those who are confused, often deteriorate when separated from familiar surroundings. Patients who have experienced both usually say they prefer to be at home. For pneumonia, heart failure and flare-ups of chronic lung disease, the evidence is now reasonably strong.

In practice, hospital at home is neither cheap nor simple. It requires a nurse with the right skills to be available seven days a week, a doctor who can be reached at night, oxygen and intravenous drugs in the house, and a hospital bed kept free in case the patient has to return. None of this is beyond a well-funded health system, but all of it costs money, and some of the savings that appear in official figures are produced by not counting these things at all.

The evidence is also narrower than the enthusiasm it has generated. Trials recruit patients who are stable enough to be randomised and who have somebody at home to help them; they rarely include the very frail, the acutely confused or those who live alone. A treatment that works well for a fit seventy-year-old with pneumonia may be quite unsuitable for her neighbour. Some virtual ward programmes have expanded faster than the evidence behind them, and it is not always clear which patients are admitted to them or what happens to those who deteriorate overnight.

Safety is the obvious objection, and it deserves a serious answer rather than a dismissive one. A ward has a nurse within calling distance at three in the morning; a house may have nobody. Deterioration can be rapid, and the delay involved in summoning help from a distance may matter. The counter-argument is that hospitals carry their own risks, and that a patient watched closely by a capable relative may be safer at home than one who is left alone on a ward.

The cost that is most consistently left out of account is the one borne by families. Home treatment assumes a carer: somebody who can answer the door, keep an eye on a drip, cook, wash and stay awake. In most countries that person is a woman, often a daughter in her sixties, and she may have to give up work or sleep for a fortnight. Studies that do count this time find that the savings shrink or vanish. A service that is cheaper for the treasury because it transfers work to an unpaid relative is not obviously cheaper for society, and it may not be cheaper at all.

There is also a question of fairness. A spare bedroom, a reliable telephone line, a warm house and a carer are not distributed evenly, and a service that depends on them will be easier to provide in prosperous suburbs than in crowded flats or remote villages. The risk is a two-tier system in which well-housed and articulate patients are treated at home while the poor remain on wards — or, worse, in which those without support are quietly excluded from a service presented as universally available.

It is sometimes argued that home care will solve the shortage of hospital beds. It will not. Even the most enthusiastic programmes keep beds empty for patients who may need to return, and the patients who most need hospital care are precisely those who cannot be treated anywhere else. Hospitals remain essential for surgery, for intensive care and for the growing number of very old people with several conditions at once. Home care can relieve pressure; it cannot replace capacity.

My own view is that the expansion should continue, but on conditions that are rarely stated so plainly. It should be funded as an addition to hospital care rather than as a substitute for it, and it should be offered only where the evidence for that condition is good. It should come with money for community nursing, with real support for carers, including the right to refuse, and with honest evaluation of what happens to patients afterwards. Above all, the decision to treat somebody at home should be made by clinicians and patients together, not by managers counting beds.