All About Cataracts

Modern cataract surgery may have long-term benefits for people with glaucoma and ocular hypertension, according to a new study.

Researchers in Arkansas, Washington and Utah reviewed the medical charts of 266 non-glaucoma patients who underwent phacoemulsification (or “phaco”) cataract surgery to evaluate both short-term and long-term changes in IOP after cataract removal with intraocular lens (IOL) implantation.

Elevated IOP is a risk factor for glaucoma. Lowering IOP may reduce a person’s risk of developing the disease.

All cataract extractions were performed using a technique called “temporal clear corneal phacoemulsification,” in which a small incision is created in the peripheral cornea and an ultrasonic probe is inserted through the opening. This probe breaks the cataract into small pieces so it can be removed more easily.

IOP measurements were taken with a Zeiss Humphrey IOLMaster (Carl Zeiss Meditech), a non-contact automated device, prior to surgery and 1 day, 1 week, 3 months, 6 months, 1 year and 2 years after surgery.

The researcher found that phaco cataract surgery produced both short-term and long-term reductions of IOP, compared with pre-operative measurements. Mean reduction of IOP was:

• 8.2 percent at 3 months
• 4.6 percent at 6 months
• 6.7 percent at 1 year
• 7.8 percent at 2 years

The authors of the study concluded that temporal clear corneal phacoemulsification cataract surgery results in a decrease in intraocular pressure that persists for at least two years following surgery.

SOURCE: Intraocular pressure change after temporal clear corneal phacoemulsification in normal eyes. Acta Ophthalmologica. February 2010.

Bausch & Lomb (Rochester, N.Y.) recently announced the U.S. launch of its new Akreos MICS lens, a foldable intraocular lens (IOL) designed for implantation through a 1.8 mm incision during phacoemulsification cataract surgery.

The ability to insert the new acrylic lens through such a small incision offers several potential advantages, including faster healing and less surgically-induced astigmatism, according to the company.

The lens also features aspheric optics designed to reduce spherical aberration and produce excellent post-operative vision. (Spherical aberration is a common higher-order aberration that can degrade vision and cause glare and halos around lights.)

The new Akreos IOL represents a new level of micro-incision cataract surgery (MICS). With most other IOLs used in MICS, an incision of 2.2 mm to 2.75 mm is required.

Prior to phacoemulsification technology, incision sizes of 10 mm or greater were common in cataract surgery, with greater risks of eye infection, delayed healing and other cataract surgery complications.

Because the Akreos MICS lens is a premium IOL, it may increase your cataract surgery cost if you choose this implantable lens for your surgery.

The Akreos MICS is the latest addition to Bausch & Lomb’s Akreos line of IOLs. First introduced in Europe over 10 years ago, more than 3 million Akreos IOLs have been implanted worldwide, according to the company.

Cataract surgery does not cause a progression of early age-related macular degeneration (AMD) to a more sight-threatening stage of the disease, according to a new study.

Researchers in Australia performed cataract surgery on 27 eyes of 27 patients with early macular degeneration to see if removal of their cataracts would improve the patients’ vision and quality of life without increasing their risk of AMD progression and vision loss from choroidal neovascularization (CNV).

CNV is the growth of fragile new blood vessels in the choroid layer of the eye underlying the retina. In macular degeneration, these blood vessels can leak into the retina, causing “wet” macular degeneration and severe vision loss.

Prior to the phacoemulsification cataract surgery performed in the study, all patients underwent a test called fundus fluorescein angiography (FFA) to make sure no eyes had pre-existing CNV.

Data gathered 6 months after surgery revealed a 2.8-line mean improvement in visual acuity (measured with a standard eye chart) and a 2.1-fold average gain in quality of life scores (measured by a patient survey) after cataract removal. One eye (3.7 percent) developed CNV within 6 months of surgery.

The researchers concluded that there was no significant increase in short-term risk of progression from dry AMD to CNV following uncomplicated phacoemulsification cataract surgery, and that there are distinct benefits of cataract surgery in people with early macular degeneration.

Source: Cataract surgery in high-risk age-related macular degeneration: A randomized controlled trial. Clinical & Experimental Ophthalmology. Published online June 22, 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.