What is Cataract
Cataracts are cloudy areas in the lens inside the eye – which is normally clear. Cataracts can develop in one or both eyes. If they develop in both eyes, one will be more severely affected than the other. A normally clear lens allows light to pass through to the back of the eye, so that the patient can see well-defined images. If a part of the lens becomes opaque light does not pass through easily and the patient’s vision becomes blurry – like looking through cloudy water or a fogged-up window. The more opaque (cloudier) the lens becomes, the worse the person’s vision will be.
There are two types of cataracts:
- Age related cataracts
They appear later in life; the most common form. Males and females are equally affected.
- Congenital cataracts (childhood cataracts)
These may be present when the baby is born, or shortly after birth. Cataracts may also be diagnosed in older babies and children – these are sometimes referred to as developmental, infantile or juvenile cataracts.
Age Related Cataract
A patient with cataracts will eventually find it hard to read, or drive a car – especially during the night. Even seeing people’s facial expressions becomes difficult. Cataracts are not usually painful. The patient’s long-distance vision is more severely affected at first.
As cataracts develop very slowly most people do not know they have them at first. However, the clouding progresses and vision will gradually get worse. Stronger lighting and eyeglasses can help improve vision. Nevertheless, eventually the vision impairment affects the patient’s ability to carry out everyday tasks. At this point the individual will need surgery. Fortunately, cataract surgery is usually a very effective and safe procedure. Cataracts cause more vision problems globally than any other eye condition or disease.
The following factors may increase a person’s chances of developing cataracts:
- Close relatives who have/had cataracts (family history).
- Ionizing radiation exposure – airline pilots have an increased risk of nuclear cataracts compared with non-pilots, and that risk is associated with cumulative exposure to cosmic radiation.
- Statins – people who take statins have a higher risk of developing age-related cataracts.
- Long-term exposure to bright sunlight.
- Long-term use of corticosteroids.
- Previous eye inflammation.
- Previous eye injury.
- Exposure to lead – lifetime lead exposure may increase the risk of developing cataracts.
- Crystallins loss of function – A specific type of protein (crystallins) begins to lose function as the eye ages. As the protein loses function, small peptides, made of 10 to 15 amino acids, start forming and accelerate cataract formation in the eye.
How Cataract is treated ?
Surgery is the only way to remove the Cataract.
What are the symptoms of age-related cataracts ?
Symptoms usually creep up many years after onset – usually when the person is elderly. Progressively, more of the lens becomes cloudy. People with mild cataracts will not notice, they usually have it for a long time.
Cataracts often affect both eyes, but rarely equally.
When should I Plan my surgery ?
- Blurry, cloudy, or misty vision.
- Some describe it as similar to looking through frosted glass.
- Vision may be affected by small spots or dots.
- The patient sees small patches which blur parts of his/her field of vision.
- Vision gets worse when lights are dim.
- Vision is sometimes worse when light is very bright (glare).
- Some people with cataracts also comment that colors appear less clear and faded.
- Reading becomes very difficult, and eventually impossible.
- Glasses need to be changed more frequently.
- Eventually wearing glasses becomes less effective.
- In some rare cases patients can see a halo around bright objects, such as car headlights or street lights.
- Double vision in one eye (rare).
- As the person’s vision deteriorates, and the glare of oncoming headlights and street lights gets worse, driving becomes awkward and potentially very dangerous – research carried out by optometrists and psychologists in Australia shows that motorists suffering from cataracts are less able to spot potentially dangerous hazards on the roads. Drivers with cataracts eventually start suffering from eyestrain and find themselves blinking more frequently in an attempt to clear their vision.Cataracts do not usually cause any change in the appearance of the eye. Any discomforts, such as irritation, aching, itching or redness are most likely caused by some other eye disorder.Cataracts are not hazardous to the sufferer’s health, or the health of the eye. If the cataract becomes hypermature (completely white), the sufferer may experience inflammation, headache and some pain. Hypermature cataracts need to be removed if there is inflammation or pain.
Under ordinary circumstances cataract surgery is not an emergency situation except few rare instances. Therefore in most of the cases the choice of undergoing surgery largely depends upon patients. In the past, surgeons usually waited till the time Cataract becomes mature or ripe, but modern technique an advances have now made possible to perform Cataract removal at early stage. When it interferes with your day to day work, it is time for surgery. However, it is advisable to have cataract operated early before it becomes hard. An Ophthalmologist can give proper guidance.
How are cataracts diagnosed ?
Anybody who experiences vision problems should see a GP (general practitioner, primary care physician), an ophthalmologist, or an optometrist. The GP will most likely refer the patient to an ophthalmologist, or an optometrist. Following test are performed
- Visual acuity test – this tests how clearly the individual can see an object. It tests the person’s sharpness of vision. The patient reads letters from across a room. The two eyes are tested separately (one is covered). By using a chart with progressively smaller letters, the specialist can determine how acute the patient’s vision is. The chart is called a Snellen Eye Chart.Sometimes the chart has to be read twice – once with, and once without bright lights. This will give an indication of glare sensitivity.
- Slit-lamp examination – this is a microscope which allows the specialist to see the structures at the front of the eye. An intense line of sight (a slit) is used to illuminate the cornea, iris, lens, as well as the space between the iris and the cornea. The slit makes it possible for the specialist to see these structures in small sections, making it easier to spot any problems.
Dilated examination – eye drops are administered which dilate the pupils, providing a bigger window to the back of the eyes. The specialist examines the lens for signs of cataract with either an ophthalmoscope or a slit lamp. If signs of cataract are found, the specialist can also determine how dense the clouding is.
Treatment of cataracts
If the patient is found to be only mildly affected surgical treatment may not be needed. During its early stages, stronger glasses and brighter lights may help improve vision. The following simple approaches may assist people who are not ready yet to have surgery:
- Make sure your glasses are the most accurate prescription possible.
- Use a magnifying glass for reading.
- Get brighter lamps for your house. Halogen lights may help a lot.
- Wear sunglasses to reduce glare on sunny days.
- Try to refrain from driving at night.
The specialist will recommend surgery if the patient:
- Is having difficulties looking after someone else.
- Cannot drive, or finds driving difficult.
- Has problems leaving the house.
- Finds it hard to see or recognize people’s faces.
- Has problems doing his/her job.
- Cannot read properly.
- Can no longer watch television properly.
The cloudy lens is removed from the eye and an artificial clear plastic one is put in its place – an intraocular implant (intraocular lens). The operation is commonly performed is phacoemulsification or small incision cataract surgery.
Pre-operative assessment (assessment before surgery)
The specialist will assess the patient’s eyes and general health. During the pre-operative assessment the lens power is calculated which will be implanted in the patient’s eye.
The day of the operation – before it begins
Eye drops that dilate (widen) the pupils will be administered just before the procedure. The doctor may inject local anesthetic around the eye. As soon as the anesthetic starts working the area will be numbed and the patient will feel nothing. During the operation he/she will be aware of a bright light, but will not be able to see what is happening.
Various types of replacement lenses may be used:
- Monofocal lens – this is a fixed-strength lens which is set for one level of vision – usually distance vision.
- Multifocal lens – this type of lens may have two or more different strengths; near and distance vision.
- Accommodating lens – this type of lens is the most similar to the natural human lens. It allows the eye to focus on near and distant objects.
After the Operation
Most patients will experience vision improvement virtually immediately. It may take a while for the eye to settle down completely. The cut in the eye may occasionally need a stitch – in most cases, however, it is so small that it heals by itself. Patients should avoid vigorous activities for a while. Most individuals find they can go about their daily activities as soon as they get home. An appointment will be made next day to see if everything is fine.
There is no other way to cure cataracts. Medications, dietary supplements, exercise or optical devices are not effective. As mentioned earlier, during the early stages there are some things the patient can do to help see things better – but they are only temporary.