Cataracts are cloudy areas that form in the lens, which is normally transparent. They are the principal cause of loss of vision in people over 40 years of age.
Cataracts cause more vision issues globally than any other eye disorder or disease and with the aging population the number of cataracts is increasing.
There were 20.48 million cases in the US in 2010, rising to 24.41 million in 2015. Nearly 50 million Americans are predicted to get cataracts by 2050.
A cataract makes a section of the lens blurry, or cloudy. Sight doesn’t easily pass through, and vision becomes blurred, like seeing through a fogged-up window. The more blurry the lens is, the worse the vision becomes.
Congenital cataracts can occur at birth, or appear shortly after, or during infancy or childhood at some stage.
Later in life, age-related cataracts occur, and are the most common type. This article will concentrate on cataracts linked to ageing.
Cataract surgery is nowadays a routine procedure, and the most common form of eye surgery.
Surgery
The only successful treatment for serious cataracts is surgery.
The specialist will recommend surgery if the patient:
- Is having trouble looking after themselves or 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 their job
- Cannot read or watch television properly
Patients who take alpha-blockers or are considering taking alpha-blockers should be mindful that these medications will make cataract surgery more difficult.
What to expect in surgical procedures
Pre-operative evaluation: The doctor would examine the patient’s eyes and general health prior to surgery. The eye will be tested to help prepare the new artificial lens.
Before the operation: eye drops will be given to dilate or expand the pupils just before the procedure. The eye drops may also contain an anesthetic, or the doctor may inject local anesthesia into the tissue around the eye.
When the anesthetic begins to function, the region gets numb and the patient can feel nothing. They will be conscious of a bright light during the operation but they will not be able to see what is going on. Cataract surgery is typically a keyhole, or minimally invasive, operation and on the same day the patient will return home.
Various types of replacement lens may be used:
- A monofocal lens is a fixed-strength lens that is set for one level of vision, usually distance
- A multifocal lens may have two or more different strengths, providing for near and distance vision
- An accommodating lens is most similar to the natural human lens. It allows the eye to focus on near and distant objects
The procedure involves removing the blurry lens from the eye and inserting it in place of an artificial, clear, plastic one. This is an implant intraocular, or intraocular lens.
This is called phacoemulsification, or extraction phaco-extracapsular.
The eye surgeon makes a tiny cut in the front cornea and inserts through the cut a minute of a scope. The probe uses ultrasound and breaks up very small pieces of the cloudy lens. What are all being sucked out.
You then insert the artificial lens through the hole. The capsule of the lens functions as a pocket, to keep the lens in place. The lens is folded when it is first inserted but it opens when it is in place.
The whole process takes about 30 minutes to complete. For a limited period, most patients will wear an eye-pad for safety.
Other operating procedures
The lens is cut in one piece for manual extracapsular extraction, and no ultrasound is used to break it up. The surgeon can make the cut in the eye slightly wider.
In intracapsular extraction it removes both the capsule of the lens and the lens. It sews the artificial lens into the eye. This form of procedure is considerably less common.
Usually this is performed 4 weeks apart if both eyes are to be working.
Cataract surgery may be done using conventional instruments, or laser-assisted.
Laser may be used later to address a condition known as after-cataract surgery, which can occur months or years later.
After the operation
Vision improves almost instantly for most patients. It can take a while for the eye to fully calm down. Often the cut in the eye involves a stitch, but usually this is small enough to heal on its own.
Patients can stop physical activity for a while, but as soon as they get home, most people feel they can go about their everyday activities.
The patient will need a vision test, since after their operation they will possibly need new glasses. Only after their vision has settled down will the new glasses be decided, but that can take several weeks.
Symptoms
Cataracts typically take years to grow and appear to show up in older age. Gradually, the lens is getting blurry.
Cataracts can make it difficult to read or drive a car, especially at night. It can get tough to see the facial expressions of people.
They grow slowly, because most people don’t realize they have them at first, but the vision eventually gets worse as the clouding progresses. At the outset, long distance vision is more seriously impacted.
Cataracts often impact both eyes, but not on a level playing field.
People with cataracts can have the symptoms of following:
- Blurry, cloudy, or misty vision
- Vision may be affected by small spots or dots
- The patient sees small patches that blur parts of the field of vision
- Vision worsens when lights are dim
- Vision is sometimes worse when there is very bright light, or glare
- Some people with cataracts also comment that colors appear less clear and faded
- Reading becomes difficult and eventually impossible
- Glasses need to be changed more frequently
- Eventually wearing glasses becomes less effective
- Rarely, the person may see a halo around bright objects, such as car headlights or street lights, or have double vision in one eye
As vision worsens, and the glare of the oncoming headlights and street lights worsens, driving becomes risky. Cataract drivers begin feeling eyestrain and find themselves blinking more often as they try to clear their vision.
Cataracts typically do not affect the looks of the eye. Any discomfort such as pressure, pain, scratching or redness is more likely to be caused by another eye disease.
Cataracts are not harmful to the person’s health or to the eye. If the cataract becomes hypermature, or white, inflammation, headache and some pain can occur. It is necessary to remove a hypermature cataract which causes pain or inflammation.
Causes
Everyone may develop a cataract, but age is the biggest risk factor.
More than 40 percent of people aged 75 or older in the U.S. have a degree of clouding of the lens. About half of all Americans aged 80 or older have a serious deterioration in their vision from cataracts.
Factors which may increase the risk of cataract development include:
- Age
- Family history
- Diabetes
- Long-term exposure to bright sunlight
- Previous eye inflammation
- Previous eye injury
Because of exposure to ionizing radiation, airline pilots are more likely to develop nuclear cataracts.
Treatment
If the effect is mild it does not require surgical care. Stronger lenses and shinier lights can help enhance vision during the early stages.
The following tips could help people who are not yet ready for surgery
- Make sure any glasses have the most accurate prescription possible
- Use a magnifying glass for reading
- Get brighter lamps for the house, such as halogen lamps
- Wear sunglasses to reduce glare on sunny days
- Avoid driving at night
These are preventive steps, as the cataracts will begin to grow and the eyesight will deteriorate.
As daily activities become more difficult to carry out, the person will need surgery. Typically that is a safe and successful procedure.
Prevention
People should have frequent eye exams to reduce the complications of cataracts, particularly as they get older.
The following tips could reduce the risk of cataracts developing. Some have proved to be successful while others have not been confirmed.
Giving up smoking: Smoking increases the risk of a variety of eye disorders and studies have related this to a 3-fold rise in cataracts. There are also signs that smokers may earlier develop symptoms of cataracts.
Nutrition: A healthy diet decreases disease risk, including eye problems. A balanced diet includes 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.
In the prevention of cataracts, lutein and zeaxanthin were identified as “promising“
Obesity and diabetes: Obesity greatly increases the risk of developing type 2 diabetes, which is a contributing factor for cataracts. Maintaining a healthy weight and maintaining control of diabetes can help minimize the risk.
Other factors which may help protect against cataracts are:
- Wearing sunglasses that block UV radiation when in sunlight
- Get at least 7 hours of good quality, continuous sleep every night
Research has suggested that pycnogenol, a pine bark extract, may help reduce the risk of cataracts.
Types
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.
Diagnosis
Anyone who has issues with vision should see a doctor, who will then refer them to an ophthalmologist or optometrist.
An ophthalmologist specializes in the eye’s medical and surgical care, while an optometrist offers eye care but not procedure.
Tests are carried out by the eye specialist.
These may include:
- 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.
Dilating the pupils in a retinal test gives a wider view to the back of the eyes. The specialist investigates the lens for signs of a cataract, and to see how dense any clouding is.
