All About Cataracts

The use of a femtosecond laser may bring added precision and safety to modern cataract surgery, according to William W. Culbertson, MD, who spoke at the recent annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS).

Dr. Culbertson is professor of ophthalmology and director of cornea and refractive surgery services at the Bascom Palmer Eye Institute, University of Miami Miller School of Medicine (Miami, Fla.).

The laser used in laser-assisted cataract surgery is the same type of femtosecond (FS) laser used to create the flap on the surface of the eye during all-laser LASIK surgery. In cataract surgery, it is used to create self-sealing incisions in the cornea, through which the cataract surgeon inserts surgical instruments to remove the cataract and replace the cloudy lens with an intraocular lens (IOL) to restore vision.

The FS laser also can be used to create small, partial-thickness cuts in the cornea (called limbal relaxing incisions) during cataract surgery to correct astigmatism. It also can be used to make a precise opening in the anterior portion of the capsule that surrounds the eye’s natural lens to give the surgeon easy access to the cataract and reduce risks associated with creating this opening with a hand-held surgical tool.

Dr. Culbertson and colleagues recently conducted a study of a proprietary femtosecond laser system (OptiMedica) for cataract surgery in the Dominican Republic. They found that the added precision of the femtosecond laser in creating the opening in the anterior lens capsule may help surgeons more accurately position an IOL in the eye during cataract surgery.

Proper centration of the intraocular lens is essential for optimal visual outcomes, especially when premium aspheric IOLs, multifocal IOLs and accommodating IOLs (Crystalens) are used.

Researchers also are finding the femtosecond laser can be used to segment and soften the cloudy lens, reducing the energy required to break up the cataract with an ultrasonic probe (phacoemulsification) and remove it from the eye with suction, Dr. Culbertson said.

Disclosure:  Dr. Culbertson serves as a consultant to OptiMedica, a medical device company that has developed a femtosecond laser-assisted cataract surgery system. At this time, the OptiMedica system is not FDA approved for use in the United States.

SOURCE:  Benefits of femtosecond laser extend to cataract surgery. Ophthalmology Times. June 15, 2010.

In the past, if you developed cataracts, the only question was when to have cataract surgery.

But today, with recent advances in cataract surgery technology, you can choose among several types of intraocular lenses your cataract surgeon can implant in your eye during the procedure to correct your vision.

In the May 15, 2010 online edition of The Wall Street Journal, Health Journal columnist Melinda Beck outlined the latest intraocular lenses available and the additional cataract surgery cost associated with premium IOLs that reduce your need for bifocals and reading glasses after surgery.

Among the choices noted:

Accommodating IOLs that flex inside the eye in response to focusing effort to restore vision at all distances. Currently, Bausch & Lomb’s Crystalens is the only brand of accommodating IOL that has gained FDA approval for use in the United States. Added cataract surgery cost for a Crystalens IOL: $2,200 to $3,500 per eye.

Multifocal IOLs that have more than one lens power, like bifocal contact lenses. Several brands of multifocal IOLs are available. Added cost for a multifocal IOL: $2,200 to $3,500 per eye.

nanoFLEX IOL. This premium IOL, produced by STAAR Surgical Company (Monrovia, Calif.) is made of a soft biocompatible material called collagen. STAAR’s current nanoFLEX IOL does not yet have FDA approval to be marketed as an accommodating IOL, but cataract surgeons who have used the device say it provides a wider range of vision than conventional IOLs. Currently, the nanoFLEX does not cost significantly more than other monofocal (single-power) IOLs covered by Medicare.

Ms. Beck says that though less than 20 percent of people undergoing cataract surgery today are choosing premium IOLs, that may change as more seniors see the value of paying extra for premium IOLs that reduce their dependence on eyeglasses after surgery.

Computer-based vision training improves uncorrected visual acuity and contrast sensitivity after cataract surgery, according to a study presented today at the 2010 annual meeting of the Association for Research in Vision and Ophthalmology (ARVO).

The researchers evaluated the effectiveness of stimulation of the visual cortex of the brain to improve vision after the surgery, using a commercially available computer-based vision training program (RevitalVision, LLC; Lawrence, Kan.).

The vision training was performed on 60 eyes of subjects that had undergone cataract surgery and had one of five styles of intraocular lenses implanted after removal of their cataracts. The mean age of the subjects was 68 years.

Uncorrected visual acuity and contrast sensitivity at both distance and near were tested at 1 month and 3 months after surgery. In the weeks between these measurements, subjects underwent 20 sessions of vision training using the computer-based RevitalVision Cortex Vision Training (CVT) program.

After CVT, mean improvement in uncorrected visual acuity for all subjects was 1.3 lines on a standard eye chart for distance vision and 1.0 line for near vision. Mean improvement in contrast sensitivity function was 223 percent for distance vision and 197 percent for near vision.

Subjects demonstrated gains in uncorrected visual acuity regardless of the type of intraocular lens (IOL) they received during their cataract surgery: aspheric monofocal IOLs, Crystalens accommodating IOLs or multifocal IOLs.

The research was authored by ophthalmologists G.O. Waring IV, MD, (Emory University School of Medicine; Atlanta Ga.), J.D. Hunkeler, MD, (University of Kansas Medical Center; Prairie Village, Kan.) and R.L. Lindstrom, MD, (University of Minnesota; Minneapolis, Minn.)

About ARVO: The Association for Research in Vision and Ophthalmology is the world’s largest eye and vision research organization with more than 12, 500 members from more than 80 countries. Membership is ARVO is multidisciplinary and includes ophthalmologists, PhDs, optometrists and other vision researchers. For more about ARVO, visit www.arvo.org.

Premium intraocular lenses designed to correct astigmatism — called toric IOLs — produce excellent visual outcomes and high patient satisfaction, according to a new study.

Researchers in Canada evaluated the implantation of toric IOLs in subjects undergoing cataract surgery in both eyes. The study included 234 eyes of 117 subjects. In addition to having cataracts, all subjects had from 1.00 to 2.50 diopters (D) of corneal astigmatism prior to surgery.

After cataract removal, all eyes were implanted with an AcrySof Toric IOL made by Alcon (Fort Worth, Texas).

Binocular uncorrected distance visual acuity (UDVA), refractive error, and IOL rotational stability were assessed at 1 day and 1, 3 and 6 months after surgery.

Prior to surgery and at 3 months and 6 months after surgery, patients completed a questionnaire that assessed their dependence on eyeglasses, visual disturbances and satisfaction with their vision using a 10-point scale (1 = completely unsatisfied; 10 = completely satisfied).

Results of the study included:

• Binocular UDVA after surgery was 20/40 or better in 99 percent of patients and 20/20 or better in 63 percent of patients.
• Mean residual refractive astigmatism after surgery was reduced to 0.4 D among all patients.
• IOL alignment was within 5 degrees of the intended position in 91 percent of patients and within 10 degrees of intended in 99 percent of patients.
• 69 percent of patients reported never needing glasses for distance vision after surgery.
• The frequency and severity of halos and glare present prior to surgery were significantly reduced after surgery.
• Satisfaction with vision was rated 7 or higher by 94 percent of patients after surgery.

The researchers concluded that cataract surgery with bilateral implantation of toric IOLs to correct pre-existing astigmatism produced “excellent and stable visual outcomes that patients rated as highly satisfactory.”

A full report of the study is published in the April 2010 issue of Journal of Cataract and Refractive Surgery, the official journal of the American Society of Cataract and Refractive Surgery (ASCRS) and the European Society of Cataract and Refractive Surgeons (ESCRS).