Cataracts are cloudy areas that form in the lens, which is normally transparent. They are the main cause of vision loss in people aged over 40 years.
Cataracts cause more vision problems globally than any other eye condition or disease, and the number of cataracts is increasing with the aging population.
In the United States in 2010, there were 20.48 million cases, rising to 24.41 million in 2015. By 2050, nearly 50 million Americans are expected to have cataracts.
A cataract causes a part of the lens to becomes opaque, or cloudy. Light does not pass through easily, and vision becomes blurry, like looking through a fogged-up window. The cloudier the lens, the worse the vision will be.
Congenital cataracts may be present at birth or appear shortly after, or at some time during infancy or childhood.
Age-related cataracts appear later in life and are the most common type. This article will focus on age-related cataracts.
Cataract surgery is a routine operation nowadays and the most common kind of eye surgery.
A doctor will normally recommend surgery for cataracts.
For severe cataracts, the only effective treatment is surgery.
Patients who take alpha-blockers or are considering taking alpha-blockers should be aware that these drugs may increase the difficulty of cataract surgery.
Pre-operative assessment: Before surgery, the specialist will assess the patient's eyes and general health. The eye will be measured so that the replacement artificial lens can be prepared.
Before the operation: Eye drops will be given just before the procedure, to dilate, or widen, the pupils. Sometimes the eye drops will contain an anesthetic, or the doctor may inject local anesthesia into the tissue around the eye.
As the anesthetic starts working, the area will become numb, and the patient will feel nothing. During the operation they will be aware of a bright light, but they will not be able to see what is happening. Cataract surgery is normally keyhole, or minimally invasive, surgery, and the patient will return home on the same day.
The operation involves removing the cloudy lens from the eye and putting an artificial, clear, plastic one in its place. This is an intraocular implant, or an intraocular lens.
This is known as phacoemulsification or phaco-extracapsular extraction.
The eye surgeon makes a tiny cut in the cornea at the front and inserts a minute probe through the cut. The probe uses ultrasound and breaks up the cloudy lens into very small pieces. These are sucked out.
The artificial lens is then inserted through the cut. The lens capsule acts as a pocket, to hold the lens in place. When it is first inserted the lens is folded, but it unfolds when in position.
The whole procedure takes around 30 minutes. Most patients will wear an eye pad for protection for a short while.
In manual extracapsular extraction, the lens is removed in one piece, and no ultrasound is used to break it up. The surgeon will make a slightly larger cut in the eye.
In intracapsular extraction, both the lens capsule and the lens are removed. The artificial lens is sewn into the eye. This type of procedure is much less common.
If both eyes need operating, this will usually be done 4 weeks apart.
Cataract surgery may be done using traditional tools, or it may be laser-assisted.
Laser may later be used to solve a complication known as after-cataract surgery that may occur months or years later.
For most patients, vision improves almost immediately. It may take a while for the eye to settle down completely. Sometimes, the cut in the eye needs a stitch, but this is normally small enough to heal by itself.
Patients should avoid vigorous activities for a while, but most people find they can go about their daily activities as soon as they get home.
The patient will need a vision test, because they will probably need different glasses after their operation. The new glasses can only be determined after their vision has settled down, but this can take several weeks.
Cataracts cause the lens to become cloudy.
Cataracts normally take years to develop, and they tend to appear in older age. The lens gradually becomes cloudy.
Cataracts can make it hard to read or drive a car, especially during the night. Seeing people's facial expressions can become difficult.
They develop slowly, so most people do not know they have them at first, but as the clouding progresses, the vision gradually gets worse. Long-distance vision is more severely affected at the beginning.
Cataracts often affect both eyes, but rarely equally.
As vision deteriorates, and the glare of oncoming headlights and street lights gets worse, driving becomes dangerous. Drivers with cataracts start to experience eyestrain and find themselves blinking more frequently as they try to clear their vision.
Cataracts do not usually change the appearance of the eye. Any discomfort such as irritation, aching, itching or redness is more likely caused by another eye disorder.
Cataracts are not hazardous to the health of the person or the eye. If the cataract becomes hypermature, or completely white, there may be inflammation, headache, and some pain. A hypermature cataract that causes pain or inflammation needs to be removed.
Anyone can develop a cataract, because the greatest risk factor is age.
In the U.S., over 40 percent of people aged 75 years or above have some degree of lens clouding. Over half of all Americans aged 80 or greater have their vision significantly impaired by cataracts.
Airline pilots are more likely to develop nuclear cataracts, because of exposure to ionizing radiation.
If the impact is mild, surgical treatment may not be needed. During the early stages, stronger glasses and brighter lights may help improve vision.
These are temporary measures, because the cataracts will continue to develop and the eyesight will worsen.
As it becomes harder to carry out everyday tasks, the individual may need surgery. This is usually a safe and effective procedure.
To minimize the complications of cataracts, people should have regular eye exams, especially as they get older.
The following tips can reduce the risk of developing cataracts. Some have been proven to work, while others are not confirmed.
Giving up smoking: Smoking raises the risk of a number of eye conditions, and studies have linked it to a 3-fold increase in cataracts. There are also indications that smokers may experience cataract symptoms earlier.
Nutrition: Healthy food reduces the risk of disease, including eye problems. A healthy diet has plenty of fruits, vegetables, whole grains, unrefined carbohydrates, good quality fats, such as avocado, olive oil, and omega oils, and either plant-sourced proteins or lean, animal-sourced proteins.
Lutein and zeaxanthin have been described as "promising" in preventing cataracts.
Obesity and diabetes: Obesity significantly raises the risk of developing type 2 diabetes, a cataract risk factor. Maintaining a healthy weight and keeping diabetes under control will help reduce the risk.
Research has suggested that pycnogenol, a pine bark extract, may help reduce the risk of cataracts.
There are different types of cataract. Some of them are not related to age.
Secondary cataract: These can develop after eye surgery for other conditions, such as glaucoma, or as a result of health issues such as diabetes. Steroid use may increase the risk.
Traumatic cataract: An eye injury may trigger a cataract, up to several years later.
Radiation cataract: Some type of radiation exposure can lead to cataract formation.
Congenital cataract: A cataract may be present at birth, often in both eyes. They do not always affect vision, but if they do, surgery may be needed.
Anybody who experiences vision problems should see a doctor, who then may refer them to an ophthalmologist or optometrist.
An eye examination and some tests can reveal a cataract.
An ophthalmologist specializes in the medical and surgical care of the eye, while an optometrist provides eye care, but not surgery.
The eye specialist will carry out tests.
A visual acuity test, to find out how clearly the person can see an object. It involves reading a list of letters from across a room.
A slit-lamp examination uses a microscope to inspect the cornea, the iris, the lens, and the space between the iris and the cornea.
Tonometry measures the pressure inside the eye.
A retinal examination is carried out after using eye drops to dilate the pupils.
In a retinal examination, dilating the pupils provides a larger window to the back of the eyes. The specialist examines the lens for signs of a cataract, and to see how dense any clouding is.
Nordqvist, Christian. "What you need to know about cataracts." Medical News Today. MediLexicon, Intl., 19 Dec. 2017. Web.