What Is a Cataract?
Inside the front of the eye is a lens, much like the lens of a camera. Its function is to focus light rays onto the retina (the film in the camera) at the back of the eye, which then transmits pictures of what you see to the brain. This lens must remain clear for the light to properly pass through and reach the retina. When all or part of the lens becomes cloudy, like a whitewashed window, the vision becomes blurred. This clouding is referred to as a cataract. A cataract is part of the lens. It is not a film or growth over the eye.
Causes of Cataracts
There are several types of cataracts. Some can be present from birth (congenital) and others can form due to an injury to the head or eye (traumatic). Some are disease related (diabetes). Most cataracts are the result of the normal aging process of the eye. Over 95% of today?s population over 60 years of age have some degree of cataract development.
Symptoms of a Cataract
Dimming and blurring of vision are the main symptoms of cataracts. Colors may seem faded or altered and reading may become difficult or even impossible. With some types of cataracts, sunlight, car headlights, or halos around lights at night may be very irritating and interfere with vision. Many patients feel as though a film is covering their eye, however, this is really the cataract (clouded lens) which is obstructing vision from inside the eye and is not a film on its surface (Fig. 1).
Treatment for a Cataract
Surgery is the only effective treatment for cataracts when glasses are no longer an option. There are no medicines, diets, or drops that will make a cataract go away. There is no laser surgery available at the present time to remove a cataract.
Decision to Have A Cataract Removed
In the great majority of cases, you are the one who will decide when to have cataract surgery. In the past, surgeons usually waited until a cataract reached the mature or ripe stage to remove it. However, modern surgical advances have made it safe and possible to perform cataract surgery at any stage of development. Therefore, if you are not able to drive a car and your lifestyle requires it; if you have difficulty reading and you do a lot of it; if you cannot do your own shopping; if you are losing a lot of golf balls; if you are forced to make significant changes in your way of life because of poor vision, you will probably want, and can, have your cataract removed. Cataract surgery is the most successful of any surgery on the body with success rates of 98% or higher.
Preparing for Surgery
There are several steps that are required prior to surgery. A standard medical examination and laboratory tests will be performed by your medical doctor to ensure your general health for surgery. Your eye will be measured by painless ultrasonic waves (Intraocular Lens Biometry) to determine the dimensions of your eye and the prescribed power of the intraocular lens implant that will be required to correct your vision, once the cataract has been removed
Intraocular Lens Biometry
While biometry, the method used to calculate the power of the Intra-Ocular Lens (IOL) which will be used to replace your clouded lens or cataract, is very accurate in the majority of patients, the final result may be different from what was planned for many reasons. Most commonly, as the eye heals the IOL can shift very slightly toward the front or the back of the eye. The amount of this shift is not the same in every patient and it may cause different results than predicted. Errors in measurement, machinery, or calculations can also cause the result to be different than expected. Patients who are highly nearsighted or highly farsighted have the greatest risk of differences between planned and actual outcomes. Patients who have had LASIK or other refractive surgeries are especially difficult to measure precisely and may have very different outcomes than planned. If the eye’s visual power after surgery is considerably different than what was planned, glasses or contact lenses may be needed, surgical replacement of the IOL might be considered, or refractive laser surgery may be used to correct the error. There may be additional costs for these procedures.
There are several methods used to remove cataracts. Each has its advantages and disadvantages. Each patient is evaluated individually for the type of surgery and type of intraocular lens implant (IOL) best suited for their particular cataract and their particular eye.
Some physicians and acquaintances may tell you they had laser removal of their cataract. There is no laser technique for removal of the original cataract. They have probably had Phacoemulsification, and are calling it laser – even though it is not .The Phacoemulsification technique (Fig.1) is the most advanced technique for cataract removal and is normally performed on an outpatient basis under local or topical anesthesia. The operation takes about 20 minutes and is usually painless during and after the surgery.
The lens of the eye is like an orange with a peel around the outside and a central core (Fig. 1). We call the outside peel the CAPSULE and the inner core, the CATARACT. In the Phacoemulsification technique, the front capsul or peel is removed. The core or cataract is then broken into many small particles by an ultrasonic probe and suctioned out of the eye, leaving the posterior capsule (peel) behind (Fig. 1). A plastic, acrylic, or soft silicone lens implant is then placed where the natural lens was, resting on the posterior capsule (peel). Intraocular lens implants are the most natural way to restore your vision after cataract surgery and are used in almost all cases.
There are several Intraocular lens implant options available to achieve distance vision and/or near vision after the cataract or clouded lens has been removed.
www.acrysofiqtoric.com (link to our preferred toric IOL)
www.tecnisiol.com/patient.htm (link to our preferred standard IOL)
www.amo-inc.com/products/cataract/refractive-iols/tecnis-multifocal-iol (link to our preferred multifocal IOL)
Astigmatism is a condition where the eye is shaped more like a football than a baseball with different curves at different angles. This means that there is no single point of focus, but rather multiple focal points. With cataract and lens implant surgery, most people without astigmatism will see reasonably well after surgery in the distance even without glasses. Glasses will be needed for near vision no matter what (unless a multifocal lens is chosen).
This is not true for patients with astigmatism who will need glasses after surgery for distance and near vision if the astigmatism is not corrected. The astigmatism can be corrected in one of two ways:
1. LRI – Limbal Relaxing Incisions are incisions in the cornea, which reduce or eliminate the astigmatism.
2. Toric lens implants correct astigmatism internally within the lens implant itself.
Either method will likely allow patients with astigmatism to see in the distance without glasses, just like those patients without astigmatism (or near if a multifocal implant is used). There are added, out-of-pocket costs for these procedures (ask office staff for fees).
When Lasers Are Used
In a certain percentage of patients (about 30%), at any time after surgery the posterior capsule, which is left behind, may become cloudy and the vision may again become impaired months or years after cataract surgery. This clouding is referred to as a secondary membrane. Should this occur, a small opening must be
made in the clouded capsule to allow light to pass through to the retina. This previously required another major surgery, but now there is a laser available in our office, which can remove this membrane. The YAG laser can be used to remove a cloudy capsule in just a few minutes and allows you to go right home! Visual improvement usually occurs within a day or two.
Lens Implants for cataract surgery
Modern day cataract surgery involves the implantation of lenses to correct vision.Depending on the patients needs and desires, different types of lenses allowing you to see at different distances can be implanted. image
TYPES OF LENS IMPLANTS:
1. Monofocal Lens Implant – You can choose to have a monofocal (single focus) lens implant for distance vision and wear separate READING GLASSES. This is the conventional procedure – meaning costs are usually deductibles only, if you have insurance or Medicare.
2. Monovision Lens Implant – With this method, a different powered implant is placed in each eye- one for near vision and the other for distance vision. This combination of one distance eye and one reading eye is called monovision and would allow you to read without glasses. This technique has been employed quite successfully in many contact lens and refractive surgery patients; however, results of this technique cannot be guaranteed. There is an added out-of-pocket cost for this technique.
3. Multifocal IOL (Lens Implant) – These lens implants (IOLs) provide distance vision AND restore some or all of the focusing (accommodating) ability of the eye for near vision. Depending upon the technological features of these IOLs, they may be described as accommodating, apodized diffractive, or presbyopia-correcting. All of these lenses are multifocal, meaning they correct for both distance vision and some other ranges, such as near or intermediate. These lenses are referred to as a Premium lenses/ procedure and there is an added out-of-pocket cost for this technique.
4. Toric Lens Implant- implant designed to correct astigmatism
These surgeries are usually performed using clear corneal, small incision-sutureless technique, though a single suture is sometimes needed.