Next-generation phaco system design improves stability, reduces energy

Reviewed by Mitchell Shultz, MD

A next-generation phacoemulsification platform (Stellaris Elite with Adaptive Fluidics technology, Bausch + Lomb) is designed to improve stability of the eye during cataract surgery. Early clinical results suggest the system enables better maintenance of anterior chamber depth, which is especially useful for eyes with shallow chamber depth or high posterior pressure as it provides overall stability while reducing phaco energy used. 

“The concept of adaptive fluidics is to be able to increase the chamber pressure during occlusion to reduce the effect of the post-occlusion surge,” said Mitchell Shultz, MD, cataract, cornea, and refractive surgeon, Shultz Chang Vision, Los Angeles.

“When material is aspirated, there is less fluctuation of the anterior chamber,” he explained. “Adaptive fluidics enables the user to increase anterior chamber pressure, which, in turn, facilitates the ability to increase the vacuum pressure setting. By getting to higher pressure and maintaining stability, we are able to reduce the amount of phaco energy used intraoperatively.”

Dr. Shultz discussed results of benchtop comparisons, as well as his clinical experience. The bench trial compared the performance of this system with its adaptive fluidics and another platform (Centurion with Active Infusion, Alcon Laboratories). He uses both platforms, in addition to having prior experience with another system (WhiteStar Signature, Johnson & Johnson Vision).
 

Adaptive fluidics

Adaptive fluidics

Adaptive fluidics is a pressurized fluid delivery system that modulates fluid pressure in response to the aspiration vacuum the surgeon commands. The higher the vacuum commanded, the higher the source pressure, creating more fluid flow.

“In the past, the surgeon would set the infusion bottle height to account for the highest vacuum they might command with the foot control during surgery,” said Brian McCary, director of innovation and design, Bausch + Lomb. He heads the team that developed Adaptive Fluidics.

“That meant that when they were commanding lower aspiration rates, they would have more pressure in the eye than they needed,” he noted.

Adaptive fluidics provides increased fluid flow to the eye only when the surgeon steps fully down on the foot pedal to command the maximum amount of potential aspiration when the phaco needle is occluded. When the occlusion breaks, there is higher infusion to keep the eye stable during the break.

Gravity feed

Dr. Shultz compared the Elite platform using conventional gravity feed and adaptive fluidics with the Centurion Active Infusion. When using gravity feed, the Elite machine allowed a post-occlusion surge of 47.7 mm Hg, similar to the Active Infusion 48.4 mm Hg. When using adaptive fluidics, the Elite post-occlusion surge was 22.5 mm Hg.

Adaptive fluidics also gives the surgeon the option of increasing IOP as high as 150 mm Hg during surgery. The higher pressure can help expand eyes with shallow anterior chambers or chamber subject to high posterior pressure as is commonly seen in obese patients. Expanding the capsule facilitates cortical cleanup in these patients as well as in patients with flaccid capsules.

Higher IOP also improves the efficiency of phaco. In his initial case series of 27 patients, Dr. Shultz needed less phaco energy in cases with up to 3+ nuclear sclerosis. He reported a mean effective phaco time of 0.54 seconds compared with an expected mean of 2.48 seconds. Absolute phaco time (APT) was 3.29 seconds compared with conventional APT of 12.65 seconds. Most cases used between 35 and 60 ml of fluid.

“The less fluid you use, the less trauma to the endothelium,” he said. “Less phaco energy and less fluid used translate into better corneal clarity the day after surgery.”

The manufacturer is also finalizing a cloud-based system that will let users manage data flow and communicate with company support staff on demand. The feature is not yet released, McCary said, but will function like a help button and provide other benefits in development, such as remote diagnostics and real-time interaction.

Remote monitoring

“We have tried to make the user interface as intuitive and as straightforward as we can, but no interface can be optimized for every situation,” he said. “So we’re going to provide a button you can push and get an immediate call from one of our support people to walk you through the solution.”

The new data platform in development is intended to provide the same interconnected, data-driven experience that surgeons and staff are accustomed to experiencing with their personal devices. Data collection will be HIPAA-complaint, McCary said.

Remote monitoring will allow the company to spot and address any developing systems issues on individual devices before they evolve for facilities, surgeons, or patients.

Mitchell Shultz, MD

E: izapeyes@gmail.com

Dr. Shultz has financial relationships with Bausch + Lomb, Glaukos, and Sun Pharma.