Refractive IOLs – An Alternative to LASIK Eye Surgery
Refractive IOLs are man-made intraocular lenses that are designed to be implanted inside the eye during cataract surgery, refractive cataract surgery, or refractive lens exchange (RLE) to restore or correct vision.
"Refractive" means "light-bending." Refractive IOLs bend or alter the direction of light rays so the eye can focus images clearly on the retina.
Trends in Cataract and Refractive Surgery
Traditionally, IOLs used in cataract surgery were spherical, monofocal lenses that could only correct nearsightedness or farsightedness. Unless a monovision correction was attempted, reading glasses were nearly always required after surgery.
Also, the goal of cataract surgery in the past was to simply restore vision that was lost due to clouding of the eye's natural lens. Due to less sophisticated surgical tools, techniques and instruments to measure the shape and power of the eye prior to surgery, people who had cataract surgery usually needed to wear bifocal or multifocal eyeglasses after surgery to correct residual nearsightedness, farsightedness, astigmatism and presbyopia.
Advances in LASIK and other refractive surgery procedures in recent years have enabled millions of people to eliminate their need for corrective eyewear. These advances have spurred the development of non-laser vision correction procedures using intraocular lenses—including phakic IOLs, which are implanted inside the eye without removing the eye's natural lens; and refractive IOLs, which are implanted after the natural lens is removed.
Many people desire refractive surgery, but, for one reason or another, they are not good candidates for LASIK or other laser vision correction surgery. Often, these people are excellent candidates to have their vision corrected with intraocular lenses.
At the same time, because of the success and popularity of LASIK and other refractive surgery, cataract patients have developed increased expectations of being free from eyeglasses after cataract surgery. As surgical and IOL technology has improved, the techniques and tools for cataract surgery and refractive surgery have become nearly the same, leading to the development of a new type of vision surgery called refractive cataract surgery.
The goal of refractive cataract surgery is a higher standard than that of traditional cataract surgery. In addition to safely removing the eye's cloudy lens and restoring functional vision with an IOL, refractive cataract surgery patients expect to have good vision at all distances with little or no need for corrective eyewear after surgery.
In many cases, today's modern refractive IOLs can meet this goal of decreased dependence on prescription eyewear—whether a person has cataracts or simply wants better vision without glasses or contact lenses and is not a good candidate for LASIK or other laser procedures.
Types of Refractive IOLs
For many years, all intraocular lenses were spherical monofocal (single power) lenses made of hard plastic. Today, a wide variety of premium IOLs are available for use in refractive lens exchange, cataract surgery and refractive cataract surgery. These include:
Aspheric monofocal IOLs
Monofocal IOLs are lenses that have just one lens power. This means they can correct only a specific amount of nearsightedness or farsightedness.
Traditional monofocal lenses are spherical in shape, meaning the curvature of the lens is uniform from the center to the periphery. But the natural human lens is not spherical—its curvature gradually changes from its center to its periphery. This non-uniform curvature is called asphericity, and lenses exhibiting this feature are called aspheric lenses.
Replacing the eye's aspheric natural lens with a traditional spherical IOL results in optical imperfections that cause a loss of clarity due to glare, halos, starbursts and other visual disturbances. This is especially noticeable in low-light situations, such as when driving at night.
Aspheric monofocal IOLs are advanced lenses that more closely mimic the shape and optics of the eye's natural lens. By doing so, these lenses are designed to provide sharper, clearer vision than traditional IOLs, especially at night.
One popular aspheric IOL is the Tecnis IOL produced by Advanced Medical Optics (Santa Ana, CA). The Tecnis IOL has an aspheric surface designed with wavefront technology similar to that used in wavefront LASIK.
Toric IOLs
Approximately 20 percent of people who want refractive surgery or need cataract surgery have a significant amount of pre-existing astigmatism.
Traditional IOLs do not correct astigmatism, so people undergoing refractive lens exchange or cataract surgery with these lenses will need a follow-up surgery, such as LASIK, to avoid the need for eyeglasses or contact lenses after surgery.
Toric IOLs, like toric contact lenses, have special designs to correct astigmatism. Examples of toric IOLs include the STAAR Toric IOL (STAAR Surgical Co., Monrovia, CA) and the AcrySof Toric IOL (Alcon, Inc., Hünenberg, Switzerland).
Accommodating IOLs
Accommodating IOLs are a special type of premium refractive IOL designed to correct presbyopia as well as nearsightedness or farsightedness. The central optical portion of an accommodating IOL is mounted on flexible legs (or haptics) that allow the lens to move slightly in the eye in response to focusing effort. This movement creates a magnifying effect to improve near and intermediate vision for reading a book or seeing a computer screen clearly.
Currently, the only FDA-approved accommodating multifocal lenses for use in the United States are Bausch & Lomb's Crystalens IOLs.
Multifocal IOLs
Multifocal IOLs are refractive intraocular lenses that contain two or more lens powers to correct presbyopia as well as nearsightedness or farsightedness. The optical designs of multifocal IOLs are very similar to those of multifocal contact lenses.
FDA-approved multifocal IOLs include Alcon's AcrySof ReSTOR IOL and AMO's ReZoom Multifocal Lens.
Refractive IOL Cost
Insurance policies vary, but Medicare, supplemental insurance policies for people covered by Medicare, and private health or vision insurance will typically cover most or all of the costs associated with basic cataract surgery procedure with a conventional monofocal IOL.
Premium refractive IOLs cost more than traditional monofocal intraocular lenses. If you choose to upgrade to refractive cataract surgery with a premium refractive IOL like any of the lenses listed above, you typically will be required to pay "out-of-pocket" the difference in cost between these premium IOLs and the allowance your insurance company provides for a conventional monofocal IOL.
Refractive lens exchange is considered an elective surgical procedure. Therefore, most insurance policies do not cover any of the costs associated with RLE.
Prior to proceeding with any surgery involving the use of a premium refractive IOL, ask someone at your doctor's office or a representative of your insurance provider to explain your policy coverage and out-of-pocket expenses.
You can lower your out-of-pocket surgical costs by setting up a Health Savings Account (HSA) at your bank or contributing to flexible health benefits program at work. Many refractive surgeons also offer financing programs that allow you to pay for the procedure over time at attractive interest rates or interest-free over a limited time frame.
Note: This information is for general education purposes only. It is not to be used as a substitute for medical advice from your eye doctor or refractive surgeon.
