CATARACTS

Definition
 

A cataract is a clouding or loss of clarity of the natural lens of the eye.

 

Cataracts are increasingly common with aging and can occur in one or both eyes.

 

Cataracts do not spread from one eye to the other.

What causes cataracts?
 

 

Cataracts can occur with age, trauma, use of certain medications (notably steroids) and can be associated with diseases (e.g., diabetes).

 

 

Cataract progression may be exacerbated by social habits (e.g., smoking and alcohol use). 

 

Extensive sun-exposure has been linked with cataract formation.

 

Importantly, what is an insignificant cataract in one eye or in one person's life may be more impacting to another.

How can cataracts affect my life?
 

Cataracts can cause many visual effects:

  • Clouding of vision
    • Cataracts typically start in a small part of the lens and may be noticable to the ophthalmologist but not the patient.
    • The vision may worsen so gradually that the patient does not notice or adjusts to it without realizing.

    • As the cataract advances, the vision may get duller or darker.

 

  • Change in color perception
    • As cataracts develop the lens transforms from clear to yellow and eventually to brown.
    • This change does not necessarily reduce acuity (vision) but color-sensitive people can misinterpret or incorrectly perceive color. Amazingly, people do not realize that this change has occured until after the cataract is removed.
  • Glare and/or sensitivity to light
    • Some cataracts do not reduce acuity, such that the patient can see small letters on the chart, but the patient may be distracted by glare from lights.
    • Glare and halos are particularly distressing when driving at night, crossing the street in bright daylight, or working at a computer.
 
 Because the majority of cataracts advance gradually, people adapt to these visual  changes and fail to notice the progressive compromises in their vision.
What are the common symptoms of a cataract?
 

In face of the typically gradual evolution of cataracts, the patient adjusts to their development aming the ophthalmologist the best qualified to identify the cataract and correlate a cataract's impact on the patient's vision.

Cataracts may cause:
  • Blurred or cloudy vision
  • Glare and/or halos around lights
  • Double images or 'ghost' images in one eye
 
  • Color changes or fading of colors
  • Reduced night vision
  • Difficult achieving a proper spectacle correction
How is a cataract diagnosed?
 

Cataracts are usually diagnosed by the ophthalmologist during a comprehensive examination.

 

The symptoms of a cataract may be elusive, and cataracts are often discovered during routine exams, or visits prompted by the patient's perceived need for new glasses. The patients often do not realize that they have cataracts.

 

 

In the event that the vision is compromised, other causes for this compromise must be assessed as well.

 

The discovery of a cataract does not necessarily imply that surgery is needed.
The visual impact of a cataract must be assessed in the context of an individual's lifestyle and needs.

 

How is a cataract treated?
 

Cataracts are treated surgically.

 

The faulty lens is replaced with a synthetic, permananet lens.

 

Cataract Surgery
 

Cataract surgery is performed as an outpatient in a hospital or at an ambulatory surgery center. Only one eye is operated on in a given day.

 

The lens is pulverized and removed as a semi-liquid (phacoemulsification). This allows for faster, safer surgery that requires no stitches.  Usually topical anesthetic (drops applied to the eye) is all that is needed, but the surgery is always performed in a proper opearting room at a hospital or ambulatory surgery center.

 

 

The older concept of a 'mature' or 'ripe' cataract is no longer as desirable.  Since no stitches are used and the eye usually recovers quickly, there are fewer restrictions afterward, but this depends on variables like the degree of surgical difficulty, the age of the patient and the severity of the cataract.

 

How is the cataract lens replaced?
 

The cataract lens is removed and a synthetic lens is inserted in its place.  The lens is self-retaining (requires no stitches) and will last the duration of a person's life time.

 

The Intraocular lens (IOL) can be made of many materials and can have many different (refractive) qualities that can help to reduce or eliminate a person's dependency on glasses.

Is a LASER used in cataract surgery?

 

Until recently the answer was no.  Femtosecond Laser has been introduced into cataract surgery as an elective adjunct to the conventional procedure.

 

The Femtosecond Laser allows for 'bladeless' incisions, a more refined capsulotomy (incision into the front surface of the lens) and softening of the cataract (by making many laser incisions in the lens, thus converting a 'block' of ice into tinier 'cubes').

 

The application of this technology reduces the trauma of 

 

 

 

of surgery, thereby reducing the surgical risk and speeding visual recovery.  Of course, this technology also requires an out-of-pocket investment by the patient.

 

PREMIUM INTRAOCULAR LENS IMPLANTS (IOL's)

 

Premium IOL's enjoy the name 'premium' for two very different reasons

 

1.            They provide an additional refractive (glasses-related) advantage

2.            They require that the patient pay a 'premium' over the usual cost of cataract surgery

 

Essentially, PREMIUM IOL's come in three categories.  The choice of which type of IOL, and which specific IOL is correct for a given patient, is the amalgam of a patient's personal needs and preferences and the judgment of the surgeon.

These lenses are not multifocal and cannot compensate far and near vision in the same eye.

 

Usually, when an astigmatic lens is used, the eye is measured again at the time of surgery after the cataract has been removed. The measuring device is incorporated into the microscope. In this way, the artifacts imposed by the cataract are eliminated and a maximally accurate reading of the eye's native prescription can be made. 

 

This same technology is used to assure that the placement of the lens is ideal. 

 

 

ASTIGMATIC:        Astigmatic implants, also known as TORIC LENSES, are intended to compensate a person's native (Toric)                    astigmatism in order to reduce that individual's need for spectacles that correct astigmatism. 

 

Astigmatic implants, also known as TORIC LENSES, are intended to compensate a person's native astigmatism in order to reduce that individual's need for spectacles that correct astigmatism. These lenses are not multifocal and cannot compensate far and near vision in the same eye.

 

 

MULTIFOCAL:      Multifocal lenses come in many varieties. In the correct patient, these lenses can supplant the need                                 for glasses at all distances: far, intermediate (the computer) and near.  

A patient's candidacy for these implants depends on the amount of astigmatism that the patient has, the pre-surgical refraction, history of prior ophthalmic procedures, binocularity (whether both eyes work well together), and if both eyes will be receiving the same lenses in near proximity. Other ophthalmic conditions may also override a person's eligibility for these lenses.

 

Multifocal lenses are NOT like progressive spectacles.  There is no need to move your head to see far vs. near.
Some patients will see halos around lights, especially at night. This diminishes over time for some, but not all patients.

 

 

ACCOMODATING:     

 

 

 

 

These lenses are somewhat flexible and help the person, by capitalizing on their native musculature, to bring near images into relative focus without glasses.

 

The range of near vision with these lenses is not as extensive as with multifocal implants, but there is far less likelihood of halos or adverse visual effects.

A patient's candidacy for these implants depends on the amount of astigmatism that the patient has, the pre-surgical refraction, history of prior ophthalmic procedures, binocularity (whether both eyes work well together), and if both eyes will be receiving the same lenses in near proximity. Other ophthalmic conditions may also override a person's eligibility for these lenses.

 

DO CATARACTS COME BACK?      

No.  A cataract is the lens of the eye, so once removed, it cannot recur.  

 

However, as explained above, the challenge of cataract surgery is the preservation of the original lens' capsule (outer peel). Because this tissue is organic, it can become hazy much like the cataract itself.  This is often referred to as a secondary cataract.

 

EVOLUTION OF 

A CAPSULAR

OPACITY

 

 

 

 

The hazy capsule, also called a capsular opacification, can interfere with vision, since light that passes through the lens must then pass through the posterior capsule. Symptoms may include:

  • reduced clarity

  • haze

  • glare

  • double vision in one eye, monocular diplopia,  as opposed to binocular diplopia, or double vision with both eyes.

    • monocular diplopia exists in one eye only and does not disappear when the other eye is closed

    • binocular diplopia is present only when both eyes are open and goes away when either eye is closed.

  • ghosting around images

  • less commonly, distortion, or metamorphopsia.

 

While a capsular opacity, or secondary cataract, is not of great concern and is easily treated in the office, it is important to contact your ophthalmologist as soon as you note these symptoms to make sure that another, more serious ophthalmic condition is not responsible for these symptoms.

 

Does a hazy capsule require additional surgery?

 

No.  This development can be treated in the office with a

laser. The process is called photodisruption which means

creating changes in (or disrupting) tissue (the capsule)

with laser photocoagulation.

 

The laser is a Yag laser, which refers to its spectrum and is

invisible.  When the laser is focused on the hazy capsule,

it creates a series of holes in the capsule that eventually coalesce (come together) and create a hole.  

 

This hole is not structurally compromising, and the process is painless.

 

Are there risks to Yag Laser Photocoagulation?

 

Naturally, there are risks to any procedure, but they are relatively limited.  Cases of post-treatment edema (swelling) in the macula have been reported, as well as temporary elevations in the intraocular pressure, and torn and detached retinas have been observed in rare cases after treatment.

 

There are, however, predictable side effects that most patients should expect to see. These include floaters that dissipate days to weeks after treatment.