About Cataracts & Cataract Surgery

cataract vision
Normal Vision Cataract

What is a cataract?

A cataract is a clouded or opaque area over the lens of the eye--an area that is normally transparent. As this thickening occurs, it prevents light rays from passing through the lens and focusing on the retina, which is light sensitive tissue lining the back of the eye. This clouding occurs when some of the protein which makes up the lens begins to clump together and interferes with vision.

In its early stages, a cataract may not cause a problem. The cloudiness may affect only a small part of the lens. However, the cataract may grow larger over time and affect more of the lens. As less light reaches the retina, it becomes increasingly harder to see and vision may become dull and blurry. While cataracts cannot spread from one eye to another, many persons develop cataracts in both eyes.

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What causes cataracts?

Although scientists do not know for sure what causes cataracts, they suspect there could be several possible causes including:

Anatomy of the eye, internal
  • Smoking

  • Diabetes

  • Excessive exposure to sunlight

  • Steroid use

  • Diuretic use

  • Certain major tranquilizers

For several of the potential causes listed (i.e., steroids, diuretics, and/or major tranquilizers), additional research is needed to differentiate the effect of the disease from the effect of the drugs themselves.

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What are the symptoms of cataracts?

The following are the most common symptoms of cataracts. However, each individual experiences cataracts differently. Symptoms may include:

  • Cloudy or blurry vision

  • Lights that appear too bright and/or present a glare or a surrounding halo

  • Poor night vision

  • Multiple vision (i.e. double vision)

  • Colors that seem faded

  • Increased nearsightedness, increasing the need to change eyeglass prescriptions

  • Distortion of vision in either eye

Illustration of a cataract

Often in the disease's early stages, you may not notice any changes in your vision. Since cataracts tend to grow slowly, vision usually worsens gradually. Certain cataracts can also cause a temporary improvement in close-up vision, but this is likely to worsen as the cataract grows. The symptoms of cataracts may resemble other eye conditions. Consult a physician for diagnosis.

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What are the different types of cataracts?

According to the National Eye Institute, part of the National Institutes of Health, cataract types are subdivided into four groups:

  • Age-related cataracts
    The majority of cataracts are related to aging.

  • Congenital cataracts
    Some babies are born with cataracts or develop them in childhood, often in both eyes. Some congenital cataracts do not affect vision, but others do and need to be removed.

  • Secondary cataracts
    Secondary cataracts develop primarily as a result of another disease occurrence in the body (i.e., diabetes). Secondary cataract development has also been linked to steroid use.

  • Traumatic cataracts
    Eye(s) that have sustained an injury may develop a traumatic cataract either immediately following the incident, or several years later.

Other sources, including the American Academy of Ophthalmology, describe the different types of cataracts according to the cataract location on the eye lens, including:

  • Nuclear cataract
    This is the most common type of cataract, and the most common type associated with aging. Nuclear cataracts develop in the center of the lens and can induce myopia, or nearsightedness - a temporary improvement in reading vision which is sometimes referred to as "second sight." Unfortunately, "second sight" disappears as the cataract grows.

  • Cortical cataract
    This type of cataract initially develops as wedge-shaped spokes which extend from the outside of the lens to the center. When these spokes reach the center of the lens they interfere with the transmission of light and cause glare and loss of contrast. This type of cataract is frequently developed in persons with diabetes, and while it usually develops slowly, it may impair both distance and near vision so significantly that surgery is often suggested at an early stage.

  • Subcapsular cataract
    A subcapsular cataract usually starts as a small opacity under the capsule, at the back of the lens. This type of cataract develops slowly and significant symptoms may not occur until the cataract is well developed. A subcapsular cataract is often found in persons with diabetes, myopia, retinitis pigmentosa, and in those taking steroids.

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How are cataracts diagnosed?

In addition to a complete medical history and eye examination, diagnostic procedures for cataracts may include:

  • Visual acuity test - the common eye chart test (see below), which measures vision ability at various distances.

                 Picture of a standard eye chart

  • Pupil dilation - the pupil is widened with eye drops to allow a close-up examination of the eye's retina.

Other tests may also be performed to help your eye care professional learn more about the health and structure of your eye.

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What are the risk factors for cataracts?

Possible risk factors for cataracts include:

  • Age
    Probably the greatest risk factor for cataracts is age. Although age-related cataracts may develop between 40 and 50 years old, vision is usually not affected greatly until after age 60.

  • Geographic location
    Recent studies have shown that people who live in high altitudes are more at risk for developing cataracts.

  • Excessive sun exposure
    People who spend more time in the sun may develop cataracts earlier. The American Academy of Ophthalmology now recommends wearing sunglasses and a wide brimmed hat to lessen exposure to ultraviolet rays.

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Treatment for cataracts:

Specific treatment for cataracts will be determined by your physician based on:

  • Your age, overall health, and medical history

  • Extent of the disease

  • Expectations for the course of the disease

  • Your opinion or preference

  • Your tolerance for specific medications, procedures, or therapies

In its early stages, vision loss caused by a cataract may be countered with the use of different eyeglasses, a magnifying glass, or stronger lighting. When these measures are no longer helpful, surgery is the only effective treatment available for most individuals. It is important to note that a cataract only needs to be removed when vision loss interferes with everyday activities such as driving, reading, or watching television. You and your doctor can make that decision together.

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What is involved in cataract surgery?

Cataract surgery is one of the most common operations performed and one of the safest and most effective. Surgery involves removing the cloudy lens and replacing it with a substitute lens. If cataracts are present in both eyes, they cannot be removed at the same time. Your physician will need to perform surgery on each eye separately.

Cataracts are generally removed in one of two ways:

  • Phacoemulsification (also called small incision cataract surgery)
    This is the most common type of cataract removal procedure. The surgeon makes a small incision on the side of the cornea--the clear, dome-shaped surface that covers the front of the eye--where a tiny probe emits ultrasound waves to soften and break up the cloudy center of the lens. The cataract is then removed by suction through the same incision.

  • Extracapsular surgery
    During this procedure, a longer incision is made on the side of the cornea to remove the hard center of the lens; the remainder of the lens is then removed by suction.

According to the National Eye Institute, in most cataract surgeries the removed lens is replaced by an intraocular lens (IOL). An IOL is a clear, artificial lens that requires no care and becomes part of the eye. With an IOL, a person has improved vision because light will be able to pass through the retina. The recipient of the new lens does not see it or feel it.

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Single focus lenses:

The most common type of lenses used in cataract surgery are monofocal (or single focus) lenses. These can be fitted to provide either near or distance vision--most patients opt for far vision in both eyes. As a result, reading glasses are usually required after surgery, and glasses are sometimes required for vision at far distances as well. This type of lens is covered by Medicare.

Advanced lenses and treatment options:

Cataract surgery is a once-in-a-lifetime investment in your eyes that can improve your quality of life for the long term. Advanced options are available that can reduce or eliminate the need for glasses after surgery. Advanced options for patients with cataracts include: 

  • Multifocal lenses: These implants split the light coming into your eye for distance and near vision, and provide the most freedom from glasses.  In a few patients, these implants can cause halos (rings around lights at night) which tend to fade 4-6 weeks after surgery.  A corneal procedure correcting astigmatism can be performed at the same time by your doctor. Medicare provides partial coverage for these lenses.

    Patients with certain eye conditions including glaucoma, diabetic retinopathy, retinal scar tissue, corneal scars, or who previously underwent radial keratotomy, are ineligible for this type of lens. Your doctor will review your examination findings to determine if you are a good candidate.

    More information on multifocal lenses is available here and here.

  • Astigmatism Correction: The cornea (front window) of the eye can sometimes be shaped more like a football than a sphere, which is called astigmatism. If you have astigmatism of the cornea, leaving it untreated would mean you would need glasses for both distance and near vision after cataract removal.  Your doctor can use laser reshaping of the cornea or an astigmatism-correcting lens implant to treat your astigmatism at the time of cataract removal. 

    More information about Toric  IOLs, which are used to treat astigmatism, is available here

  • Accomodating Lens Implants: These implants change position within your eye based on your eye muscle effort. Accommodating lenses can treat astigmatism, but give slightly less near power than multifocal lenses.  They are typically used in patients who are ineligible for multifocals due to mild or moderate glaucoma, diabetic retinopathy, retinal scar tissue, corneal scars, or prior radial keratotomy. Medicare provides partial coverage for these lenses. 
  • Laser-assisted cataract surgery As an alternative to manual incisions, the Moran Eye Center also offers laser-assisted cataract surgery. The Alcon® LenSx® Laser adds computer control to key steps of the procedure. Its unique system analyzes high-resolution OCT images of your eye; helps the surgeon to design a customized procedure; and then, visualizes and performs the procedure on command from the surgeon. To further enhance accuracy, a patient interface connects your eye to the image-guided surgical unit, so that both the LenSx® Laser computer and the surgeon commanding it have precise, real-time images at all times during the laser procedure.

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What is an "after-cataract?"

An "after-cataract" occurs when part of the natural lens not removed during cataract surgery becomes cloudy and blurs vision. Unlike a cataract, an "after-cataract" can be treated with a technique called YAG laser capsulotomy. In an outpatient procedure, the doctor uses a laser beam to make a tiny hole in the lens to let the light pass through.

After-cataracts may develop months, or even years, after cataract surgery.

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Balamurali K. Ambati, M.D., Ph.D.

Locations
John A. Moran Eye Center (801) 581-2352
South Jordan Health Center (801) 213-4500

Specialties: Cataract Surgery, Comprehensive Ophthalmology, Ophthalmology, Refractive Surgery, Uveitis

William R. Barlow, M.D.

Locations
South Jordan Health Center (801) 213-4500

Specialties: Cataract Surgery, Comprehensive Ophthalmology, Ophthalmology, Refractive Surgery

Craig J. Chaya, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Redwood Health Center (801) 213-9940
Rocky Mountain Ophthalmology (801) 264-4464

Specialties: Cataract Surgery, Comprehensive Ophthalmology, Glaucoma, Ophthalmology

Alan S. Crandall, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Rocky Mountain Ophthalmology (801) 264-4464

Specialties: Cataract Surgery, Glaucoma, Ophthalmology

Bradley J. Katz, M.D., Ph.D.

Locations
John A. Moran Eye Center (801) 581-2352

Specialties: Cataract Surgery, Neuro-Ophthalmology, Ophthalmology, Vasculitis

Nick Mamalis, M.D.

Locations
Redwood Health Center (801) 213-9940
Rocky Mountain Ophthalmology (801) 264-4464

Specialties: Cataract Surgery, Comprehensive Ophthalmology, Geriatric Ophthalmology, Ophthalmic Pathology, Ophthalmology

Mark D. Mifflin, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Moran Vision Center at Old Mill (801) 585-3937
Rocky Mountain Ophthalmology (801) 264-4464

Specialties: Cataract Surgery, Cornea, Ophthalmology, Refractive Surgery

Majid Moshirfar, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Moran Vision Center at Old Mill (801) 585-3937
Redwood Health Center (801) 213-9940

Specialties: Cataract Surgery, Cornea, Ophthalmology, Refractive Surgery

Randall J. Olson, M.D.

Locations
John A. Moran Eye Center (801) 581-2352

Specialties: Cataract Surgery, Cornea, Eye Muscle Surgery, Ophthalmology

Jeff Pettey, M.D.

Locations
John A. Moran Eye Center (801) 581-2352

Specialties: Cataract Surgery, Comprehensive Ophthalmology, Ophthalmology

Geoffrey C. Tabin, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Redstone Health Center (435) 658-9250

Specialties: Cataract Surgery, Cornea, Ophthalmology, Refractive Surgery

Norm A. Zabriskie, M.D.

Locations
John A. Moran Eye Center (801) 581-2352
Redwood Health Center (801) 213-9940
Rocky Mountain Ophthalmology (801) 264-4464

Specialties: Cataract Surgery, Glaucoma, Ophthalmology

All clinical services and programs are part of University of Utah Hospitals & Clinics