For Patients with Astigmatism, there are two options:
1. Toric Lens Implants to neutralize astigmatism
Riverside Eye Center was the first practice in the Bluewater area to offer this new technology. Alcon’s AcrySof® Toric lens implant is designed to correct for both cataracts and astigmatism simultaneously. Implanted in the eye to restore single-distance vision after cataract surgery, the AcrySof® Toric lens has a unique patented design that provides both spherical and astigmatic correction. The AcrySof® Toric intraocular lens belongs to the trusted family of Alcon AcrySof® lens implants that are some of the most widely used intraocular lenses for cataract surgery, with more than 30 million implanted worldwide.
The AcrySof® Toric lens is designed to reduce corneal astigmatism and improve uncorrected functional distance vision.
The AcrySof® Toric lens offers these advantages over traditional lens implants:
- Correction of corneal astigmatism
- Enhanced clarity and quality of uncorrected distance vision.
- Filtered blue light protection
- Rich, vibrant color perception
The AcrySof® Toric lens is ideal for patients who wish to be corrected for distance vision and are comfortable wearing glasses. Because this lens does not offer the ability to accommodate or adjust one’s vision to varying distances, glasses would be required for near and intermediate tasks for people who have this implant.
The AcrySof® Toric lens implant is also an excellent choice for those who drive a lot at night, as it delivers great clarity with minimal reports of glare or haloes under both bright and dim lighting conditions.
Whether myopic or hyperopic, most eyes have corneal astigmatism to some degree. Corneal astigmatism means that the front part of your eye, the clear window you look through, is not perfectly round. Instead of being spherical like a basketball, an astigmatic cornea is slightly flattened, more oval in shape like a football, with one side steeper than the other (as illustrated above).
Because the astigmatic cornea is curved more (steeper) in one direction than the other, light entering the eye is refracted differently as it passes through these different areas. This causes light to come into focus at several different points on the back of the eye, rather than ideally coming into focus at just one point (note the illustration, right).
Depending on the direction and the amount of astigmatism, vision through an astigmatic cornea will be affected in various ways. The illustration (below) gives a broad example of the visual effects, depending on the overall direction of the curve.
2. Limbal Relaxing Incisions For The Correction of Astigmatism
It is most common for eye surgeons to simply prescribe glasses or contact lenses for the correction of astigmatism after cataract surgery. Some surgeons will treat corneal astigmatism at the time of cataract surgery by placing “limbal relaxing incisions” (LRI’s). This involves making tiny incisions in the cornea to “relax” or flatten the steeper meridian, thereby causing the corneal curvature to become more rounded, reducing astigmatism.
These long, thin incisions are placed at the very edge of the cornea (known as the corneal limbus) on the steepest meridian and differ in number and length according to the amount of astigmatism. Relaxing incisions generally do not eliminate corneal astigmatism completely, but rather reduce it to an acceptable level. Because the cornea is living tissue, there may be “over-response” or “under-response” to these incisions. Seldom is corneal astigmatism completely resolved; however, a significant reduction in your astigmatism produces a more satisfactory uncorrected visual result.
Some patients with extreme amounts of astigmatism may still require the addition of limbal relaxing incisions to correct astigmatism after cataract surgery with the AcrySof toric lens. For the patients, with unusually high amounts of astigmatism, implanting the toric lens means that less corneal surgery in the form of a limbal relaxing incision is needed to achieve the same amount of correction.
In the future, the AcrySof® Toric Lens will be available in higher powers of astigmatic correction so that for very high amounts of corneal astigmatism can be corrected without the need for the addition of limbal relaxing incisions.
UV Blue Light Protection
In addition to its refractive role, the natural lens inside your eye is also responsible for filtering high-energy blue light commonly found within the sun’s rays and some artificial light. As part of the aging process, your natural lens gradually turns yellow and it is thought that this change in color may help to protect the aging retina by filtering more of these harmful wavelengths.
When your natural lens is removed during cataract surgery, the eye loses the ability to filter blue light because most available lens implants are clear and filter UV light only. A cataract surgery patient receiving one of those implants is left vulnerable to the transmission of UV blue light. Some researchers believe that overexposure to blue light may be harmful to the retina and may contribute to macular degeneration and loss of vision. The AcrySof® Toric lens implant is unique in its ability to filter blue light, having a patented yellow tint that filters both UV and blue light.
The light yellow color of the AcrySof® Toric lens is very similar to that of your natural lens and is necessary to filter blue light, yet the Toric lens does not alter the natural colors of the things you see or change the quality of your vision. In fact, results of a recent study show equal or better color perception for patients implanted with the AcrySof® Toric lens as compared to the same lens without the light yellow color.
Advantages of the AcrySof® Toric Lens Implant:
- The AcrySof® Toric intraocular lens is designed to correct for nearsightedness or farsightedness and corneal astigmatism of the human eye.
- The AcrySof® Toric intraocular lens is designed to have the lens capsule “shrink wrap” around it. This helps the lens stay stable and centered within the eye.
- The patented yellow color of the AcrySof® Toric intraocular lens implant is biocompatible and bonded to the structure of the acrylic material.
- The yellow color of the AcrySof® Toric intraocular lens implant, approximates the natural discoloration (i.e., natural yellowing) of a healthy adult crystalline lens, without a negative impact on color perception.
- The AcrySof® Toric intraocular lens implant is compatible with secondary cataract treatment (i.e., Nd: YAG laser treatment) if required.
The AcrySof® Toric lens is available in a wide range of optical powers that effectively correct eye that is nearsighted and farsighted. As each patient is unique, both in physiology and in viewing distance preferences, the correct power intraocular lens for your cataract surgery will be selected using biometry equipment. An in-depth discussion of your needs and options will take place with your eye surgeon at Riverside Eye Center.
Could You Have Cataracts?
Our eyes work much like a camera. A clear lens is necessary in order for images to be focused clearly on the retina. At birth, our lenses are clear. Lenses can become “cloudy” or “yellow” over time, eventually degrading the quality of our vision. These “cloudy” lenses are referred to as “cataracts”. (please see cataract section for more information) While the development of cataracts can often be a natural result of the aging process, surgeons have been correcting distance vision for decades by replacing natural lenses with clear replacement lenses. Usually, surgery is performed when the progression of your visual disturbance is negatively impacting activities like driving, watching television, or reading. The majority of intraocular lenses that ophthalmologists use are designed to give patients good distance vision but patients still need to wear reading glasses to see things up close.
Cataract Surgery Now Offers the Benefits of Improved Near, Intermediate, and Distance Vision.
If your doctor has informed you that you are a candidate for cataract surgery, you may want to consider enhancing your procedure by selecting multi-focal lenses. Unlike standard lenses, multifocal lens design uses technology to provide patients with near, intermediate, and distance vision. Presbyopia is a condition that usually starts to affect people in their early to mid-forties when they can no longer see well up close. As a result, presbyopic patients have difficulty with activities such as reading, sewing, and using the computer. In the FDA clinical studies, the majority of patients who received the types of multifocal lenses available at Riverside Eye Center reported that they no longer needed glasses for any activities. Many patients note that after receiving these lenses, reading without glasses is as easy as it was before their forties. Even when patients opt to follow up with a pair of glasses, many find that wearing these glasses is not essential for the majority of their daily functions.
Medicare and most insurance companies cover the cost of cataract surgery using the standard intraocular lens. If you choose to proceed with a multifocal lens, Medicare will still provide up to its allowed payment for the standard procedure and operating room time. Medicare and supplementary insurance plans will not cover the cost of upgrading your lens or additional testing and evaluation.
Refractive Surgery or Clear Lens Exchange for Candidates without Cataracts
Patients without cataracts may also choose a multifocal lens to correct for farsightedness, nearsightedness, and presbyopia to give them a quality range of vision like they had when they were younger. Presbyopia is a condition that usually starts to affect people in their early to mid-forties when they can no longer see well up close. As a result, presbyopic patients have difficulty with activities such as reading, sewing, and using the computer. A procedure called a clear lensectomy, which is similar to cataract surgery, is performed to remove the natural lens and replace it with the multifocal lens. Refractive surgeries are elective procedures and therefore the patient is responsible for all costs.
While multifocal lenses are designed with the goal of providing independence from glasses and contacts for most activities, they do not guarantee that you will be completely free from needing some correction for certain tasks. Additional refractive adjustments, such as LASIK, may be needed to correct patients to their desired distance results.
What is the Crystalens® accommodative intraocular lens?
The Crystalens® accommodating intraocular lens is an intraocular lens used after cataract surgery or as a lens alternative in presbyopic lens exchange. The concept of the lens was engineered with a hinge design to allow the optic, or part of the lens that you see through, to move back and forth as your focus on an image changes. The crystalens® accommodative intraocular lens is permanently implanted with a surgical process and functions in a similar fashion as the natural eye. Once the surgery has been completed your eyes can focus on far or near objects in a comfortable way. If you are experiencing presbyopia or cataracts please feel free to consult us about the possibility of utilizing the new crystalens® accommodative intraocular lens.
How Does the Crystalens® IOL WORK?
After the age of 40 people will often start to experience difficulty reading as the eye’s natural lens starts to harden. Prior to this many people often experience excellent vision and are typically confused as to what is happening with their eyes. Because their vision may have been perfect they have never consulted an ophthalmologist as to what is naturally occurring. This inability to see at close distances or difficulty for the muscles in the eye to auto-focus can be very discouraging. This is known as loss of accommodation, or presbyopia. The Crystalens® was engineered with a hinge design to allow the optic, or part of the lens that you see through, to move back and forth as your focus on an image change.
FDA Clinical Trial Information:
- 98.4% of patients implanted with Crystalens® in both eyes could pass a driver’s test without glasses
- 100% could see intermediate (24″ to 30″) without glasses, the distance for most of life’s activities
- 98.4% could see well enough to read the newspaper and the phone book without glasses.
- Some patients did require glasses for some tasks after implantation of the Crystalens®
- Significantly more patients implanted with a Crystalens® (88.4%) could see better at all distances then patients implanted with a standard IOL (35.9%)
Frequently Asked Questions
How long does it take to heal?
Each patient is unique and the healing process will be different in each case. Most patients return to their normal work or lifestyle in two to three days. The focusing ability of the lens will not be fully realized for 6 to 8 weeks after the procedure. The eye must re-learn how to focus on objects at various distances in order to see clearly. It is important to discuss your expectation for this lens with your surgeon so that you can better understand the actual healing process.
Can my vision be corrected to 20/20, for both reading & distance?
The Crystalens® has been designed to focus your eyes at all distances after cataract surgery. While virtually everyone will experience a significant improvement in their uncorrected vision after surgery, some people will not see 20/20 at all distances. It is interesting to note that many people who have not had surgery are not able to see 20/20 at both near and far even with glasses or contact lenses. This is due to a variety of ocular and physiological problems as well as lifestyle preferences, yet most of these people function quite normally although their vision is reduced. The two-year clinical trial that supported the FDA approval of the Crystalens® indicated that 92% of the people enrolled in the study (implanted bilaterally) could see 20/25 or better at distance, 96% could see 20/20 at arm’s length and 73% could see 20/25 at near without glasses or contact lenses. What is more exciting is that 98% of these people could pass their drivers test, 100% could see their computer and dashboard, read the prices in the supermarket or put on their makeup, and 98% could read the telephone book or newspaper, all without glasses or contact lenses. It is important to keep in mind that visual acuity is subjective and depends upon each individual’s own ocular and physiological conditions as well as lifestyle preferences. Some patients implanted with the Crystalens® still require glasses for certain activities. (Courtesy of www.crystalens.com)
What makes the Crystalens® different from other intraocular lenses?
The Crystalens® has the unique ability to focus on objects at varying distances using the eye’s natural focusing system. This means that the Crystalens® can provide a continuous range of vision, without corrective lenses, from near to far and everything in between. Standard (single vision) lens implants do not have the ability to provide a full range of vision. Most people who have single vision lens implants MUST wear glasses for middle and near vision. It was shown in the two year clinical trial that supported the FDA approval of the Crystalens® that significantly more patients implanted with a Crystalens® (88%) could see better at all distances than patients implanted with a standard lens (36%).