Cataract Eye Surgery With Intraocular Lens Implants
Cataracts are one of the most common eye diseases that affect people over the age of 40. Vision with cataracts becomes cloudy and blurry gradually and can lead to blindness if not treated.
Thankfully, there is a simple procedure to remove cataracts and restore vision: cataract surgery with intraocular lens implant.
To understand cataract surgery, you'll need to know a little bit about the anatomy of a cataract.
About the Author
Melissa Flagg is an ophthalmic technician and has been examining patients on a daily basis for over 20 years.
She has had rigorous training under the supervision of an ophthalmologist and specialized in the cornea, cataracts, and retina as well as how systemic disease affects the eye. She has been certified by JCAHPO as a Certified Ophthalmic Assistant.
What Are Cataracts?
Behind the iris, the color part of the eye, is the lens. This structure is densely packed with cells inside a bag known as a capsule. This capsule is suspended by little filaments called zonules that are attached to the ciliary body or muscle, which is responsible for focusing the lens.
The zonules bend and flex the lens when pulled or relaxed by the ciliary body in order to focus on objects at different distances. This is how we are able to read up close and focus on distant objects almost instantly.
As we age, the lens hardens and yellows, usually from the center, or nucleus, outward (although there are different types of cataracts). This causes cloudy vision, an inability to read and vision that is dimmed.
The yellowing can also cause changes in color vision; however, the changes happen so slowly that they typically go unnoticed. The cataract starts to form between the ages of 40 and 50, when most people start to need reading glasses. Most ophthalmologists will not call it that however. In essence, when the lens starts to harden, a cataract is forming.
The Anatomy of the Human Lens
Cataracts can cause a variety of symptoms, and many people describe their symptoms differently. However, there are common symptoms that just about everyone experiences as their cataracts develop including:
- Blurry/hazy/foggy vision
- Inability to read at close range
- Difficulty seeing a computer screen or vehicle dashboard
- Problems with contrast sensitivity
- Glare from lights (both headlights and traditional lighting)
- Problems driving at night
- Vision that seems dim, or dark
- Changes in color perception
Cataract Treatment Options
Glasses will improve vision in the beginning of this aging process. However, when the lens starts to yellow, and is no longer able to focus at all on its own, glasses will no longer improve vision adequately. At this point, surgery is required.
Surgery is very simple and typically only takes about 10 minutes. The patient is prepped by administering anesthesia, usually Versed, a conscious sedation, and the eye is numbed with a topical anesthetic such as Marcaine. An incision is then made in the limbus, the junction between the cornea and the sclera. (If you are looking in the mirror, this junction is where the color part meets the white of the eye.)
The hardened lens, or cataract, is removed by a process called phacoemulsification, an instrument that produces a sonic wave to break up the cataract and then vacuum it out. The capsule, or bag that held the original lens, is left intact in order to hold the implant, also known as the intraocular lens (IOL).
In some cases, the capsule may rupture or rip. If this happens the surgeon may place the IOL in the sulcus, the area between the back of the iris and the ciliary body. The surgeon may also opt to place the implant in the anterior chamber, just behind the cornea, in front of the iris.
Types of Lenses
IOLs have come a long way. There are several different classes of lenses on the market, and there are several different lenses in each class (with exception of 2 classes). The classes are:
- Monofocal lenses - these are the standard implants that have been used since the inception of the IOL.
- Toric lenses - these IOLs correct astigmatism (an irregular shaped cornea)
- Multifocal lenses - these implants allow patients to see at distance and near and just about everything in between. There are a few different types of multifocal lenses.
- High definition lenses (for patients who drive at night)
- Accommodating lenses (i.e.: the Crystalens)
There is something for just about everyone, and all different lifestyles. It's important to talk with your physician to determine if you are a candidate for premium multifocal or accommodating lenses. Typically, patients with retinal pathology such as macular degeneration are not good candidates because they will not reap all of the benefits the lens has to offer.
Premium lenses do come with an extra cost. Most insurances won't pay for anything other than the typical monofocal implant. Premium lenses can range from $500 to $1500 per eye, depending on the type of lens chosen. However, choosing a premium lens can save you money in the long run since you won't be spending money on glasses or contact lenses in the future.
Dr. Kevin Barber Explains Cataract Surgery Options
Before Cataract Surgery
Before cataract surgery, the patient undergoes several different tests to determine the power of the implant. The two most important of these tests are the refraction and the A-scan.
The A-scan is essentially an ultrasound that measures the length of the eye. A patient’s refractive error (their need for glasses) is determined by the length of the eye.
In those who are nearsighted, the eye is too long, and the images land just in front of the retina instead of on it.
In those who are farsighted, the eye is too short causing images to land behind the retina. Knowing how long the eye is can give an estimate of the patient’s prescription, thus confirming the refraction.
The refraction is the test that is used to determine your glasses prescription. This is important because it changes the value of the lens power generated by the A-scan to more accurately reflect what the patient actually needs. It also tells the doctor where your astigmatism is, and whether or not it should be corrected during surgery.
Corneal topography is rapidly becoming a routine test prior to cataract surgery. This is essentially a color mapping of the cornea and all its aberrations.
This map allows the doctor to pinpoint exactly where the astigmatism is allowing him to correct it with either an implant or axial keratotomy which involves making cuts in the cornea at specific points in order to flatten the astigmatism.
There are a number of other tests that can be done including keratometry which is another method used to measure astigmatism, and OCT scans, also called Optical Coherence Tomography.
OCTs allow the doctor to see the layers of the macula and the surrounding retina to determine if there is anything pathology (such as a CNVM or swelling) that may affect the outcome of the surgery.
If at any point during this testing you feel that the person doing your tests may not be performing them correctly or you have no confidence in the person, make sure you convey this to your physician. If the numbers of the testing are off even the slightest bit, the lens power will be off and you’ll be very unhappy with the outcome.
After Cataract Surgery
After one of these lenses is implanted in the eye, the patient is taken to the recovery area for about 30 minutes to let the anesthesia wear off.
Typical cataract surgery requires no stitching or patches after the procedure. There are times when these are required, but your physician should be able to tell you prior to surgery if this will be necessary.
Cataract Surgery With a Toric Intraocular Implant
Recovery time is usually about four weeks. During the first week, the patient is not allowed to wash their hair, or lift anything over ten pounds. Patients really shouldn’t bend over to pick anything up for at least 3 days after surgery.
Swimming is not allowed for three weeks. Rigorous exercise is generally limited the first week, I always told my patients that when they can resume swimming, they will be able to get back to their exercise regimen (better to be safe than sorry.) Patients will also need to use eye drops for the duration of recovery, unless they have opted to have "dropless" cataract surgery.
During the first week patients will use an antibiotic to prevent infection and a steroid to help prevent the body’s natural immune response and prevent inflammation. These drops are typically used four times a day.
The antibiotic will usually be Vigamox or Zymaxid, but it varies from doctor to doctor. The steroid is almost universal. It is a form of Prednisolone Acetate, either generic or brand name.
Some physicians add a non-steroidal anti-inflammatory (NSAID) such as Nevanac or Ilevro one to three times a day to help alleviate any pain from possible inflammation. The antibiotic and NSAID will usually last about a week before the bottles run out. Once the drops are gone, the patient stops taking them.
The second week the physician will start to taper the steroid so that by the fourth week all drops are discontinued. At this point, the patient will be tested for eyeglasses if needed. If a second eye is to be done, it is typically done a week or more after the first eye and the final refraction for glasses will take place about four weeks after the second surgery.
© Copyright 2012 - 2015 by Melissa "Daughter of Maat" Flagg ALL RIGHTS RESERVED
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