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.

Aspheric intraocular lenses (IOLs) used in cataract surgery provide higher quality vision than spherical IOLs, according to a new study.

Researchers at Johann Wolfgang Goethe-University (Frankfurt, Germany) and Cullen Eye Institute, Baylor College of Medicine (Houston) performed bilateral cataract surgery on 26 patients. The patients received an aspheric IOL in one eye and a spherical IOL in the other. All lenses were produced by the same manufacturer (Alcon).

Aspheric IOLs feature a gradually changing curve from the center of the lens outward and are designed to control spherical aberration produced by spherical IOLs. Spherical aberration is one of many higher-order aberrations of the eye, and is believed to cause glare and halos around lights at night.

Six months after surgery, aberrometry and visual acuity measurements showed the eyes receiving the aspheric IOLs had significantly lower spherical aberration, better visual acuity (measured with an eye chart in medium/low lighting) and better contrast sensitivity than the eyes with spherical lens implants.

The researchers concluded that aspheric IOLs produce better retinal image quality and higher quality vision than spherical IOLs.

Note: Aspheric IOLs typically are considered premium lens implants, and choosing this type of intraocular lens may increase the your cataract surgery cost.

Source: Effect of intraocular lens asphericity on quality of vision after cataract removal: An intraindividual comparison. Ophthalmology. Published online July 29, 2009.

A silicone aspheric intraocular lens (IOL) reduces spherical aberration and enhances contrast sensitivity in low light compared with a conventional spherical IOL, according to a study published in the June 2009 issue of American Journal of Ophthalmology.

Sixty-two eyes of 31 patients who underwent bilateral cataract surgery were evaluated. Patients received a Tecnis Z9000 silicone aspheric IOL in one eye and a CeeOn 911A silicone spherical IOL in the other eye. Both intraocular lenses are made by Abbott Medical Optics (AMO). Follow-up exams were performed at 1, 3, 6 and 12 months after surgery.

Though both the aspheric and spherical IOLs provided essentially the same uncorrected and best-corrected visual acuity in bright and medium-light conditions, the eyes with the aspheric IOLs had fewer higher-order aberrations (specifically, spherical aberration) and exhibited better contrast sensitivity in low-light conditions, the study authors said.

Improved contrast sensitivity in such conditions suggests the Tecnis Z9000 aspheric IOLs may provide sharper vision than conventional spherical IOLs for activities such as driving at night.

Silicone aspheric IOLs generally are considered to be premium intraocular lenses. As such, your cataract surgery cost typically will be higher if you choose these lenses, and the cost of the lenses may not be fully covered by Medicare and other types of vision insurance.

The U.S. Food and Drug Administration (FDA) recently approved a new astigmatism-correcting intraocular lens (IOL) for use in cataract surgery. The new lens, called the AcrySof IQ Toric IOL, is manufactured by Alcon and is now available for use by cataract surgeons in the United States.

In addition to having a toric design to correct astigmatism, the new premium IOL also has aspheric curves to reduce a common post-surgical optical error called spherical aberration. By reducing spherical aberration, the AcrySof IQ Toric IOL is designed to improve image quality and contrast sensitivity for better night driving vision and sharper vision overall.

In a clinical trial required by the FDA prior to approval, among 37 patients who had the IOL implanted bilaterally for the treatment of cataracts and astigmatism, 98 percent did not need prescription eyeglasses for distance vision six months after surgery. Also, the lens continued to show good rotational stability when checked one year after surgery. 

According to Alcon, the AcrySof IQ Toric IOL is a good choice for any patient undergoing cataract surgery who has 0.75 diopter (D) or more corneal astigmatism prior to surgery. The IOL corrects up to 2.50 D of astigmatism, and it can be combined with a procedure called limbal relaxing incisions to correct even higher amounts of astigmatism.

Like other premium IOLs, the AcrySof IQ Toric IOL costs more than a conventional monofocal intraocular lens and will increase your cataract surgery cost. For details, consult a cataract surgeon near you.