All aspects of phaco are seeing improvement in tools

As surgeons change their practice styles, instrument makers see opportunities in providing necessary tools.

Clear corneal incisions have triggered a host of improvements to every type of surgical instrument, as the demands for safe and reproducible procedures have prompted surgical instrument makers to make more durable and better reacting equipment.

As surgeons change their practice styles over the years, instrument makers offer improved products to keep up with demand.

"Almost every single instrument has been significantly improved," said Richard Mackool, MD, a surgeon who has designed his own instruments. "There has been a new generation each year for the past decade."

The changes to surgical techniques create opportunities for instrument makers, said John Bee, chairman and president of Rhein Medical in Tampa, Fla. When surgeons started inserting foldable lenses through self-sealing tunnels, blades had to improve.

"One change usually creates all sort of opportunities," Mr. Bee said. The multiple changes in phaco have prompted new materials and designs, so incisions can be made without dimpling down or getting a curvilinear wound.

"The cataract procedure is so perfect today that doctors are looking for degrees of perfection," said Steven L. Stoll, director of marketing for Solan Ophthalmic Products in Jacksonville, Fla. "Wound architecture has become a major concern to surgeons."

Every instrument improved

Lid speculums were improved by the Leiberman instrument, which has made operating with topical anesthesia safer and easier.

"I have seen patients almost squeeze their lids closed with the standard wire speculum and literally perform part of the procedure themselves," Dr. Mackool said. "It's disastrous."

The Leiberman speculum fixes the interpalpebral distance and prevents patients from squeezing down on the keratome. It also allows adjustment during the procedure and does not collapse the globe, he said.

The demand for watertight surgery methods prompted Dr. Mackool to design a paracentesis blade that would make a standard size incision.

"We've gone through a lot of trouble to design phaco equipment and blades that control the size and leakage, so it's odd that we have not paid attention to the side port incision," he said. "Unmeasured leaking of varying amounts occurs during the procedure, reducing our ability to control IOP [intraocular pressure]."

Dr. Mackool's blade makes a reproducible paracentesis incision that is tapered from 0.75 mm outside to 0.4 mm inside.

Almost every other tool used in phaco has seen a similar improvement in performance or safety prompted by a change in surgical practice.

As the capsulorrhexis size increased, forceps were narrowed to give the surgeon a better view.

The development of hydrodissection prompted surgical instrument makers to develop a flat-tipped cannula to eliminate pressure waves that used to blow out the posterior capsule.

In order to increase the safety and efficiency of subincisional cortex removal, irrigation and aspiration handpieces were angled to 90° for better performance.

Watertight wounds

The design of diamond blades has evolved rapidly, including designs with beveling, trapezoid and rectangle shapes.

Lee Nordan, MD, designed a rectangular diamond blade, the Pathfinder offered by American Surgical Instrument Company, in Chicago, to create a watertight wound.

"What seals a sutureless wound is not the angle at which you enter," he said. "The most important thing is that you have endothelium underneath the wound, so it can create adherence of the flap to the underlying stroma."

The Pathfinder creates a different wound profile from other blades, such as Rhein's 3-D Trapezoid Blade and Solan's Diamontek tri-bevel keratomes. It has a 155° blade angle with two levels on it to measure the length of the corneal wound.

"What we tried to do with the Pathfinder is to make it just pointed enough to be used for hundreds of cases, but create a rectangular wound to increase the endothelial surface area," he said.

Metal or diamond

As clear corneal incisions have become more popular, so have the diamond blades, which make the incision easier to create.

According to Mr. Stoll, cost and handling can be more expensive with diamond blades.

"If you commit to a surgical configuration and then next week your procedure changes, you're stuck with the $3,000 diamond," he said. "They can be really expensive if you don't get 1,000 cases out of them. A diamond is an investment and needs to be maintained and cared for."

Unlike many surgeons, Dr. Mackool remains with his metal blades, which offer a tactile feel.

"These metal blades used to be dull and their tolerances were relatively poor," he said. "Now, there are some good ways of creating metal blades using very hot gases blown past them that make them sharp. They are not as sharp as a diamond, but as sharp as I want them. I would rather not have the blade so sharp that if the patient moves as the incision is being made, or if the surgeon's hand wavers slightly, that you get a markedly different cut."

Dr. Mackool makes a three-plane incision and relies upon the tactile feedback as he works the blade through the cornea.

According to Mr. Stoll, "Diamontek has several configurations with blunt sided diamonds, which provide the surgeon with a tactile response."

Rhein is now designing the metal version of its Rhein 3-D diamond blades, so surgeons can regain the tactile feedback that the diamond blades eliminate. The less expensive keratome also will allow surgeons to change their surgical approaches without paying for expensive diamond blades with each change.

For Your Information:

• Richard Mackool, MD, can be reached at 31-27 41st St., Astoria, NY 11103 U.S.A.; fax: ++(718) 728-4882; e-mail: mackool@worldnet.att.net. Dr. Mackool has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Steven L. Stoll can be reached at 6743 Southpoint Drive N, Jacksonville, FL 32216 U.S.A.; ++(904) 279-7552; fax: ++(904) 279-2630. Mr. Stoll is director of marketing for Solan Ophthalmic Products.
• John Bee can be reached at 5460 Beaumont Center Blvd., Ste. 500, Tampa, FL 33634 U.S.A.; ++(813) 885-5050; fax: ++(813) 885-9346; e-mail: info@rheinmedical.com. Mr. Bee is chairman and president of Rhein Medical.
• Lee Nordan, MD, can be reached at 9834 Genesee Ave., Ste. 209, La Jolla, CA 92037 U.S.A.; ++(619) 457-2220; fax: ++(619) 729-0700. Dr. Nordan has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.