All About Cataracts

In its December 15 issue, Ophthalmology Times published a “year in review” feature, highlighting key developments in cataract surgery that took place in 2009.

Advances in cataract surgery technology in 2009 included:

Approval of femtosecond laser technology for cataract surgery

In September, the LenSx laser (LenSx Lasers, Inc., Aliso Viejo, Calif.) became the first femtosecond laser to gain FDA approval for a specific step in the cataract surgery procedure, eliminating the need for a bladed instrument for this step. Proponents say femtosecond laser technology (currently used primarily for LASIK and other laser vision correction procedures) could make a cataract operation even more safe and effective, reducing the risk of certain cataract surgery complications.

New multifocal IOLs

Two new multifocal IOLs were introduced to the U.S. market in 2009: the Tecnis Multifocal IOL (Abbott Medical Optics, Santa Ana, Calif.) and the AcrySof IQ ReSTOR +3.0 D (Alcon Laboratories, Fort Worth, Texas). Both lenses are designed to help patients regain a fuller range of vision after cataract removal and reduce their need for reading glasses. According to preliminary studies, both lenses offer patients a higher degree of freedom from glasses than previous multifocal intraocular lenses.

Investigational IOLs

A number of companies were conducting clinical trials of new premium IOLs not yet approved for use in the United States. These include a “light-adjustable lens” (LAL) being developed by Calhoun Vision (Pasadena, Calif.). The power of this lens can be adjusted by exposing it to a specific wavelength of light 2 to 3 weeks after cataract surgery, depending on the patient’s visual needs.

Another premium IOL under study is an accommodating IOL called the NuLens (NuLens, Ltd., Herzeliya, Israel and Alicante, Spain). Preliminary studies suggest the NuLens can produce significantly greater near focusing power than currently available accommodating IOLs for even greater freedom from reading glasses after surgery.

SOURCE: 2009: A banner year in cataract surgery. Ophthalmology Times. December 15, 2009.

A multifocal IOL recently approved for use in the United States produces a wide range of clear vision and a high degree of independence from eyeglasses after cataract surgery, according to a multi-center European study published this month in Journal of Cataract and Refractive Surgery.

The study evaluated the performance of the AcrySof IQ ReSTOR IOL with +3.0 D add power implanted in both eyes of 93 patients. The procedures took place at five European sites and were performed by five surgeons.

At 6 months after surgery, mean binocular uncorrected visual acuity was better than 20/20 at distance (4 meters), approximate 20/30 at arm’s length and slightly better than 20/20 vision at the patient-preferred reading distance (approximately 16 inches).

In a postoperative survey, the mean patient satisfaction with their vision was 8.3 out of 10, and 88 percent of the patients did not need eyeglasses after surgery.

If you have cataracts and also are being treated for glaucoma, cataract surgery may reduce your need for glaucoma medications and surgery, according to a new study.

Researchers in Korea recently conducted a retrospective study of 96 people with glaucoma who underwent phacoemulsification cataract surgery with intraocular lens (IOL) implantation for the treatment of clinically significant cataracts. Forty-eight of the patients had primary open-angle glaucoma (POAG) and 48 had primary angle-closure glaucoma (PACG).

While previous studies have shown that cataract extraction with IOL implantation lowers intraocular pressure (IOP) in patients with and without glaucoma, the focus of this study was to determine which type of glaucoma patients are most likely to achieve the greatest IOP-lowering effect of cataract surgery.

The follow-up period ranged from 24 to 54 months, with a mean of 31 months.

The researchers found that cataract surgery successfully controlled the IOP of 39.6 percent of eyes with POAG and 62.5 percent of eyes with PACG. The criteria of success was attaining an IOP of 21 mm Hg or lower without medical glaucoma treatment or with fewer anti-glaucoma medications than before surgery.

Among eyes with primary open-angle glaucoma, pre-operative factors increasing the likelihood of successful IOP control after cataract surgery were a maximum IOP lower than 31 mm Hg and use of fewer than three anti-glaucoma medications.

Pre-operative factors increasing the likelihood of success among eyes with primary angle-closure glaucoma were a maximum IOP lower than 42 mm Hg, use of fewer than three anti-glaucoma medications and less than 30 percent of the drainage angle of the anterior chamber of the eye being affected by iris adhesions called peripheral anterior synechiae.

The researchers concluded that modern small-incision cataract surgery using phacoemulsification and foldable IOL implantation may help control IOP in some glaucoma patients, reducing or eliminating their need for anti-glaucoma medicine and/or glaucoma surgery.

The study was published in this month’s issue of Canadian Journal of Ophthalmology.

New research suggests it is safe to perform cataract surgery using topical anesthesia and intravenous sedation without requiring patients to fast prior to surgery.

Fasting before cataract surgery is a long-standing precautionary practice. Doing so allows the stomach to empty prior to surgery, reducing the risk of the patient aspirating contents of their stomach into their lungs when medications are given that may reduce the body’s normal protective mechanisms.

Aspiration of stomach contents during surgery can cause aspiration pneumonia, a potentially serious cataract surgery complication.

But there also are risks associated with fasting, particularly for people with diabetes.

Canadian researchers at the Department of Ophthalmology and Visual Sciences, University of British Columbia and the Department of Anesthesia, Providence Health Care (Vancouver, B.C.) performed a retrospective study of more than 5,000 cases of cataract surgery performed at Mount St. Joseph Hospital (Vancouver) between April 2007 and March 2008.

Nearly all of the cataract removal procedures (97 percent) were performed using only topical anesthesia. A small minority (3 percent) required additional anesthesia injected behind or around the eye to prevent eye movements during surgery.

Approximately 50 percent of patients received intravenous (IV) sedation for the cataract procedure, as deemed appropriate by the attending medical staff.

All patients in the study were allowed to eat and drink freely until they arrived at the hospital, approximately one hour prior to their cataract removal.

Results of the study, published in this month’s issue of Canadian Journal of Ophthalmology, indicate that there were no cases of aspiration pneumonia among the 5,125 non-fasting cataract surgery patients in the study.

The authors concluded that it is safe to perform cataract surgery under topical anesthesia and intravenous sedation without requiring patients to fast prior to surgery.