All About Cataracts

The use of premium intraocular lenses (IOLs) in cataract surgery performed in the United States is increasing, according to recent surveys.

Premium IOLs include multifocal lens implants and accommodating IOLs. Both types of presbyopia-correcting intraocular lenses give patients a broader range of vision, reducing or eliminating the need for reading glasses after cataract surgery.

According to a recent survey of cataract and refractive surgeons reported by the eyecare industry research firm Market Scope, 71 percent of U.S. eye surgeons offered their patients the option of premium IOLs in 2008, up from approximately 59 percent in 2007. The company also estimates that 210,000 presbyopia-correcting IOLs were implanted during cataract surgery or other vision correction procedures in the U.S. in 2008, up from 153,000 in 2007.

Eye surgeons also say they prefer premium IOLs for the correction of high myopia. In a 2008 member survey of the American Society of Cataract and Refractive Surgery (ASCRS) more eye surgeons responding to the survey reported preferring premium IOLs (40 percent) to LASIK (23 percent) for the correction of large amounts of nearsightedness in patients desiring elective refractive surgery.

Among ASCRS surgeons using presbyopia-correcting premium IOLs, their top three lens choices in 2008 were the AcrySof ReSTOR multifocal IOL (Alcon), the Crystalens accommodating IOL (Bausch & Lomb) and the ReZoom Multifocal IOL (Abbott Medical Optics).

Other premium intraocular lenses include toric IOLs that correct astigmatism and aspheric IOLs designed to reduce glare and improve night vision.

Premium IOLs cost more than standard IOLs, and the added expense of these lenses typically is not covered by vision insurance and must be paid out-of-pocket, increasing your cataract surgery cost. However, most people who choose premium IOLs are very pleased with the added visual benefits the lenses provide, according to eye surgeons who offer them.

Researchers at Emory Eye Center and Emory Vision (Emory University, Atlanta) recently investigated the outcomes of cataract surgery performed with multifocal intraocular lenses (IOLs). The purpose of the study was to determine reasons for patient dissatisfaction with the procedure and the outcomes after remedial actions are taken.

The researchers reviewed the cases of 32 patients who were dissatisfied with the outcomes of their cataract surgery with multifocal IOL implantation. 

Most eyes (65 percent) had received an AcrySof ReSTOR IOL (Alcon) and the others (35 percent) received a ReZoom Multifocal IOL (Abbott Medical Optics). 

Outcomes analyzed included type of visual complaint, the remedial treatment applied to address the complaint, and the degree of improvement after intervention.

Findings of the study included:

1. Thirty patients (94 percent) reported blurred vision.
2. Fifteen patients (47 percent) reported photic phenomena (visual disturbances caused by optical aberrations; also called “negative dysphotopsia”).
3. Thirteen patients (41 percent) reported both blurred vision and photic phenomena. 

Causes of blurred vision included:

• Posterior capsule opacification, or “PCO” (22 eyes, 54 percent)
• Residual nearsightedness, farsightedness or astigmatism (12 eyes, 29 percent)
• Dry eye syndrome (6 eyes, 15 percent)

Causes of photic phenomena included:

• PCO (12 eyes, 66 percent)
• IOL decentration (2 eyes, 12 percent)
• Retained lens fragment from the removed cataractous lens (1 eye, 6 percent)
• Dry eye syndrome (1 eye, 6 percent)

Remedial treatments applied to relieve patient symptoms included artificial tears and other dry eye therapy, laser surgery for PCO and surgery for IOL exchange.

Thirty-five eyes (81 percent) had improvement with conservative treatment. Five eyes (12 percent) did not have improvement despite treatment combinations. Three eyes (7 percent) required IOL exchange.

The researchers concluded complaints of blurred vision and photic phenomena after multifocal IOL implantation can be effectively managed with appropriate treatment, though a few eyes may require IOL exchange.

The study was supported in part by Research to Prevent Blindness and the National Institutes of Health.

Source: Dissatisfaction after multifocal intraocular lens implantation. Journal of Cataract and Refractive Surgery. June 2009.

Advances in cataract surgery are occurring every year, making the procedure safer and more effective than ever.

A number of the key advances in cataract surgery took place in 2008. Among the new technology and techniques:

New Phacoemulsification Technology

Phacoemulsification (or “phaco”) is a cataract surgery technique in which the cataract is broken up into small pieces with a small, hand-held probe that has a vibrating tip. The small pieces are then removed from the eye with suction. Phaco is currently the most common technique used for cataract surgery in the United States.

Manufacturers of phaco equipment for cataract surgery introduced several advances in 2008, including probes that allow the procedure to be performed with smaller incisions. This reduces the risk of unwanted astigmatism after cataract surgery. Other advances include new microsurgical tools to help break up very dense cataracts more effectively during phaco cataract surgery.

New Lens Implants

New intraocular lenses (IOLs) introduced or in development in 2008 include presbyopia-correcting IOLs, aspheric IOLs and toric IOLs.

Presbyopia-correcting IOLs

These innovative lenses help restore a person’s ability to see well up close as well as far away, thereby reducing the need for reading glasses and computer glasses after cataract surgery.

The Crystalens HD (Bausch & Lomb) presbyopia-correcting lens that was introduced in 2008 works by having the ability to change position slightly within the eye in response to focusing effort. This type of presbyopia-correcting IOL is also called an “accommodating” IOL. Other brands of accommodating IOLs are currently in development.

Another type of presbyopia-correcting intraocular lens is the multifocal IOL. Multifocal IOLs are similar in design to multifocal contact lenses, containing separate lens powers for seeing distant, intermediate and near objects simultaneously. Examples of multifocal IOLs include The AcrySof ReSTOR IOL (Alcon Laboratories) and the ReZoom Multifocal Lens (Advanced Medical Optics).

Accommodating and multifocal IOLs can be implanted in both eyes, or in one eye only for a “monovision” effect. Some surgeons feel a monovision correction provides better distance vision than having presbyopia-correcting IOLs implanted in both eyes.

Aspheric IOLs

Aspheric IOLs are specially designed to more closely mimic the shape of the eye’s natural lens, which changes in curvature from its center to its periphery. This characteristic of possessing a gradually changing curve is called asphericity (meaning “not spherical,” or “not of the same curve”).

Because they are more similar in shape to the eye’s natural lens, aspheric IOLs are designed to provide sharper vision and reduce higher-order aberrations (HOAs) caused by traditional spherical IOLs. HOAs contribute to glare and reduced contrast sensitivity, especially at night and in other low-light conditions.

Many cataract surgeons appear to believe in the benefits of aspheric IOLs, as the use of thes premium IOLs grew rapidly in 2008.

Examples of aspheric IOLs include the Tecnis IOL (Advanced Medical Optics) and the AcrySof IQ IOL (Alcon Laboratories).

Toric IOLs

Toric IOLs are a new type of premium intraocular lenses that correct astigmatism.

In the past, people who had astigmatism and cataracts had to wear eyeglasses or have an additional surgical procedure to correct their astigmatism after cataract surgery. With toric IOLs, many of these people can see clearly after cataract surgery without the need for full-time glasses or additional surgery.

Use of toric IOLs increased significantly in 2008 and continued future growth is expected. Examples of toric IOLs include the AcrySof Toric IOL (Alcon Laboratories) and the STAAR Toric IOL (STAAR Surgical Co.)

More Advances on the Horizon

As the aging of the U.S. population continues, more and more Americans are having cataract surgery. And more advances in cataract surgery technology are occurring every year, including techniques for smaller incisions and faster recovery time.

To stay up-to-date on the latest news about cataracts and cataract surgery, return to AllAboutCataracts.com often. Or browse AllAboutVision.com’s Cataract Surgeon Directory to find a cataract surgeon near you.