Cataract Surgery: What is an Intraocular Lens?
When the eye’s natural lenses are removed during cataract surgery, they are replaced by artificial lenses known as intraocular lenses (IOLs). They are also used to correct a patient’s vision during a surgical procedure known as refractive lens exchange.
Intraocular lenses are FDA-approved and have been in use since the 1980s. Prior to their invention, you had to wear special types of contact lenses or some very thick eyeglasses to enable you to regain your vision after cataract surgery, simply because there was no device that could act as a replacement for the natural lens.
There are a number of quality IOLs to choose from in the market today that can easily suit your special visual needs and lifestyle. Below is a summary of some of the best rated intraocular lenses that have been approved by the FDA in the USA. These IOLs are considered to be premium due to their advanced features that are otherwise not available in basic single vision IOLs that are found in the market.
Your surgeon will give you detailed information on the recommended IOLs that will suit your needs. He or she will also share with you any costs involved in the surgical operations. This may be done during the consultations and exams prior to your surgery.
i. Aspheric Intraocular Lenses
The natural lens of the eye is not spherical. Originally, the artificial intraocular lenses were spherical, because it is easier to produce them with this shape. This shape of the traditional artificial intraocular lenses does not resemble the natural lens found in the eye. The aspheric lenses look more like the natural lens of the eye. This is important, as the spherical intraocular lenses have a setback in situations where there is low light. In fact, the aspheric intraocular lenses improve the sharpness of vision in low light. People with larger pupils benefit more from the use of this type of intraocular lens. The following are a list of aspheric lenses available in the U.S market:
- Tecnis aspheric intraocular lenses manufactured by Abbott Medical Optics
- AcrySof aspheric intraocular lenses manufactured by Alcon Optics
- Soft Port AO aspheric intraocular lenses
- Softec HD aspheric lenses
ii. Toric Intraocular Lenses
This is hardly used in a cataract surgery. However, in case the patient has an extra condition of astigmatism or if they are either shortsighted or farsighted, then this is the best type of artificial intraocular lens to prescribe for the patient.
Given the design of the toric intraocular lens, the surgeon is able to flexibly fix the lens in adaptation of an individual’s eye. This is always done in consideration to whether the patient is shortsighted or farsighted.
At the beginning of a cataract surgery, the surgeon draws the part of the cornea that is supposed to be aligned to the toric intraocular lens. At the end of the surgery, the surgeons always fix the toric intraocular lens accordingly to match the drawing on the cornea.
Before the founding of the toric lenses, surgeons used a different method for those with astigmatism. Usually, they had to cut out some parts of the cornea such that when the cutting heals, the cornea would be more spherically shaped. This would help counter astigmatism to some extent.
Some individuals still need to cut the edges of the cornea, even if they use intraocular lenses during a cataract surgery. In such cases, the elimination of astigmatism is most likely a great success, since the toric intraocular lenses will have dealt with the greater part of the astigmatism.
In short, there are other minor surgeries that can be additionally carried out, like the LRI and the Keratotomy, but with the insertion of the toric intraocular lenses, the need for these surgeries potentially reduces. The following is a list of Toric Intraocular lenses available in the US market today:
- Tecnis toric intraocular lenses manufactured by Abbott Medical Optics
- AcrySof Toric intraocular lenses manufactured by Alcon optics
- Trulign Toric intraocular lenses manufactured by Baush and Lomb
iii. The Accommodating Intraocular Lenses
With the accommodating intraocular lenses, you have a flexible ability to adjust to the change and the range of your clear vision. Typically, the accommodating lenses are mounted such that they move depending on whether the image is near or far. If the image is close, the accommodating intraocular lenses tend to move slightly to the front, allowing the light to focus more to the retina, and thereby producing a clearer vision of the image.
Even though they don’t function on close images like the multi-focal intraocular lenses, you will find it unnecessary to use contact lenses. When considering distant images, they work exceptionally, just like the mono-focal intraocular lenses. The following are some types of accommodating intraocular lenses available in the US market:
- Crystalens Ao accommodating intraocular lens manufactured by Bausch and Lomb
- Trulgin Toric accommodating intraocular lens manufactured by Bausch and Lomb
iv. The Multi-focal Intraocular Lenses
The use of multi-focal intraocular lenses is more convenient, as you can flexibly and sharply focus on the object from a close or a far range without necessarily wearing contact lenses. Multi-focal intraocular lenses can also be used to fix presbyopia. Research suggests that at a close range, multi-focal intraocular lenses are better than the accommodating lenses. Some researchers, however, suggest that multi-focal intraocular lenses at close range might cause glare.
Mostly, when you and your eye professional decide on using a multi-focal intraocular for your cataract surgery, you are likely to use a laser cataract surgery, since the cutting of this lens needs perfection for it to work effectively. Remember that this may cost you more, since it is generally not covered by insurance. In The US, the following are the most popular multi-focal intraocular lenses in market today:
- Tecnis multi-focal intraocular lenses manufactured by Abbott Medical Optics
- AcrySof IQ ReSTOR multi-focal intraocular lenses manufactured my Alcon
v. The Mono-vision technique
This is a natural alternative of using intraocular lenses to correct presbyopia. In this event, your cataract surgeon will knowingly make one of the eyes able to see distant objects and the other to focus on closer objects. In such a case, the surgeon can use any of the above mentioned lenses to perform the cataract surgery.
In the beginning, this technique was not very popular; nowadays, people have grown fond of it and it has been a success.
Use of different types of intraocular lenses for each eye
In some rare cases, there is a need to use different lenses for each eye. Each eye is treated independently, but the surgeon always ensures they both work in conjunction. To reduce the usage of contact glasses, the surgeon may use different types of intraocular lenses in the case where both eyes have been diagnosed with cataracts. In such cases, please discuss this thoroughly with your surgeon and optician to get the best brand and best type of lens combination for your eyes.
The cost of intraocular lenses
Unlike the mono-focal lenses, other types of intraocular lenses are not covered by medical insurance. You will need to spend more on them, and in the case you use a laser type of surgery, you are likely to spend even more.
You should discuss this in detail with your surgeon to avoid running into unwanted expenses.
Finding the right type of intraocular lens is very important if you have cataracts. Be sure to discuss your options with your ophthalmologist or surgeon.