What is an Eye Cataract?
A cataract is opacity of the lens, the degree and density of which can vary enormously. Cataracts occur due to a variety of causes, but most are associated with ageing. Nearly everybody over the age of 70 has some degree of cataract.
They usually occur in both eyes, but severity differs. There are other causes, such as traumatic cataracts (commonly seen after a metal object such as when a BB air-gun bullet pierces the eye or a piece of metal damages the lens of an industrial worker). Congenital ones can take place if a mother contracts rubella during the first trimester (first three months) of pregnancy when the eye is developing.
Cataracts are also seen in older diabetics. Senile cataracts are the most common kind. Progressive blurring of the vision is the only symptom. Distant vision is usually affected more severely, and strangely, near vision is often improved in the early stages.
Patients are often delighted to find they can read better than ever, and without their usual glasses. The condition is slowly progressive. Often the patient can make do and is satisfied to lead a life of reduced visual acuity rather than undergo surgery, the only cure.
Eye Cataract Causes
A cataract simply means a clouding of the normally crystalline-clear lens. This reduces vision, until it may advance to total visual loss. The lens may appear cloudy or simply as a white circle. There is no pain. Occasionally the child may seem to develop strabismus (cross-eyes). This may be the first symptom.
In the pre-immunization days when rubella was common among pregnant women – if contracted during early pregnancy when the infant’s eyes were developing – cataract formation was fairly prevalent. But this is now much less common, fortunately.
Any penetrating eye injury may be disastrous. Pellets from air guns have been incriminated, and recently there seem to be more of these needless, serious and very sad accidents. Parents – please do not give your children these as toys unless you are prepared to police their use strictly. Too many injuries causing blindness have been reported. Certain diseases may be responsible, however. Diabetes, glaucoma and thyroid disorders are among the more probable. Some children on long-term steroid treatment may also develop this problem.
Eye Cataract Treatment
With very young children, surgeons prefer not to operate and may give drops a trial run. After the age of six years, surgery may be carried out and often an excellent result is possible. With new techniques in recent years, especially lens implants, often there may be a remarkably natural outcome. Or the child may be given special spectacles or contact lenses to wear. If there is an underlying cause, this may give rise to added problems despite surgery, but in general the outlook is relatively good.
Parents are cautioned never to neglect any failing vision in their children. Early, prompt attention is essential.
Treatment depends on the degree of visual loss. There is no simple medical treatment, and the only cure is an operation called lens extraction. In 90 per cent of cases, this can dramatically improve vision.
After the operation, the patient must avoid straining of any type for three weeks. The eyes may be bandaged for a few days. When the eyes are opened everything is 30 per cent larger. The patient is later given special glasses to wear eight weeks after the operation, which bring things into normal perspective again. However, if the patient can tolerate contact lenses, vision is virtually normal. If only one eye is involved, it is possible for the patient to regain almost normal vision again.
Eye surgeons are now able to insert an implant, so replacing the diseased cataract. This is made from an artificial transparent product, and often provides excellent near-normal vision after the operation. Implants arc a major step forward in eye surgery. Implants are now being carried out at almost any age – advancing years are no barrier if the patient is in relatively good health. Patients in their 70s, 80s and even older are undergoing this form of surgery with excellent results.
Congenital cataracts may require surgery at an early age, and results are frequently good.
Traumatic cataracts can often be prevented by people working in “at risk” industries wearing protective goggles when carrying out hazardous tasks, such as striking steel on steel. Pieces of metal may penetrate the cornea and lens at tremendous speed to become lodged in the vitreous. Fortunately, in younger people, aged 20 and younger, the lens material in a traumatic cataract may automatically become absorbed, so making surgery unnecessary. But in other instances, the lens may have to be removed to allow vision to return.