Spotlight ON TECHNOLOGY & TECHNIQUE

It's Safety First With Dewey Phaco Tip

Rounded edge helps avoid capsule breaks.

By Jerry Helzner, Senior Editor

It's impossible to perform phaco with your fingers crossed.

However, until recently, if you were a cataract surgeon and your phaco tip accidentally made contact with the capsule, all you could do was take a deep breath, say a little prayer and trust to luck that the capsule remained intact.

Now, thanks to Steven Dewey, M.D., Colorado Springs, Colo., you still have a very good chance of having an intact capsule if there is incidental contact with the rounded edge of a Dewey Radius Phaco Tip (MST, Redmond, Wash.).

Dr. Dewey invented the Dewey Radius Tip after being involved in research into various aspects of cataract removal, IOL design and IOL insertion.

"In looking at phaco needles, I concluded that, with the newer generation of phaco equipment, you didn't need a sharp edge to remove a cataract," notes Dr. Dewey. "You could have a rounded edge and protect the capsule from breaking if there was contact with the phaco tip."

As an example of how one advance in technology leads to others, Dr. Dewey is quick to note that his rounded-edge phaco tip will not be as effective with older-generation phaco equipment.

"Today's phaco machines provide more precise, targeted delivery of energy," he asserts. "Advanced fluidics and power modifications enhance ultrasound capabilities and allow the Dewey Radius Tip to permit safer cataract surgery."

Testing His Theory

Once his concept had been turned into a prototype, Dr. Dewey first tested it with simpler, less dense cataracts. He found that the power needed to eliminate a 2+ nucleus was no greater for the rounded tip than for a sharp tip. He then moved on to 3+ cataracts, where he found that some loss in power efficiency was more than offset by a greater measure of safety.

The rounded edge of the Dewey Tip protects the capsule from rupture after incidental contact.

Dr. Dewey says that in the many hundreds of procedures he has performed using the rounded tip, only once has he had a capsular rupture caused by the tip coming in contact with the capsule.

"Today, I use the rounded tip for all types of cataracts," says Dr. Dewey.

Rapid Adoption by Surgeons

His view is seconded by David Khorram, M.D., of the Marianas Eye Institute on the Pacific island of Saipan. Dr. Khorram, who encounters a number of denser, white cataracts among the island population, has no qualms about using the Dewey tip for white cataracts. He performs phaco with the AMO Compact with WhiteStar (Advanced Medical Optics, Santa Ana, Calif.).

"Some surgeons have voiced concern that the rounded edge may not be sharp enough to emulsify dense nuclei," says Dr. Khorram. "I have found that the Dewey tip cuts through the hardest nuclei without difficulty."

Since the Dewey Radius Phaco Tip was launched in early 2006, Dr. Dewey has heard from numerous cataract surgeons who are using his invention in daily practice.

"We have been gratified by the response from cataract surgeons who have adopted it," he says. "Surgeons tell me that they have had accidental contact between the tip and the capsule, expected the worst, and were relived to see that the capsule was intact."

An added advantage, notes Dr. Dewey, is that the Dewey tip helps protect the iris in cases of intraoperative floppy iris syndrome, or IFIS, which has become an increasing concern to cataract surgeons. IFIS has been linked to some of the popular alpha blockers, such as tamsulosin, taken by men to facilitate urine flow when an enlarged prostate makes urinating difficult.

MST now offers a wide range of 19- and 20-g Dewey Radius Phaco Tips in 0-, 15-, 30- and 45-degree bevels for the most widely used newer-generation phaco machines. OM