More power and more control in phacoemulsification

New system provides the ability to customize treatment to achieve greater efficiency

As science produces ever more advances and options in cataract surgery, it becomes difficult at times to compare “apples to apples.” Different types of phacoemulsification systems use different fluidics and different ultrasonic energy. Distinct grades of cataracts react differently in the surgical setting. That is why I have found it so important to identify an objective and reproducible method to measures cataract grades that can be replicated whether you are in Canada, Chile, or the Czech Republic. As surgeons, the parameters we tend to look at to see if we are doing a better job are: How much energy have I used to remove the same grade of cataract; and what was my total effective phaco time. I was recently able to isolate the element of ultrasound energy in two phacoemulsification systems to determine which provided greater phaco efficiency. In my study, two groups of 200 consecutive patients underwent surgery by the same surgeon using the WhiteStar Phacoemulsification System (Abbott Medical Optics, AMO, Santa Ana, Calif.). Both groups were evaluated using the Pentacam Nucleus Grading System PNS (Oculus, St. Louis) to establish the grade of cataract pre operatively. With the first group of 200 patients we used the WhiteStar Sovereign Phacoemulsification System and with the second group of 200 patients we used the WhiteStar Signature Phacoemulsification System. Both systems used the same advanced fluidics, same energy, and the same 20-gauge needle. In both groups, the power and duty factor of the phacoemulsification system were set according to the patient’s cataract grade using a linear correlation. The only difference between the groups was that the Signature System incorporates ELLIPS technology.
ELLIPS Transversal Ultrasound (AMO) is the first phaco technology with the ability to simultaneously blend longitudinal and transversal cutting modes. The introduction of lateral motion increases cutting efficiency by emulsifying lens material in more than one direction. This then reduces the repulsion of nuclear material, thereby increasing followability and reducing energy required to emulsify the lens. The use of less energy also reduces the risk of inadvertent trauma to the underlying epithelium. The study showed that when all other factors are the same, the transversal energy with the ELLIPS technology does, in fact, result in greater phacoemulsification efficiency. With the Signature System, the effective phaco time was statistically lower in grades 2 to 3 and 4 to 5; the balanced salt solution used was statistically lower in all grades; and the needle time was statistically lower in grades 2 to 3 and 4 to 5. The Signature System with ELLIPS technology not only has a unique elliptical cutting pattern, but also has a faster central processor and a faster pump which together result in a five-fold increase in data sampling and therefore machine response time. This facilitates the movement away from the surgeon adjusting or readjusting settings “on the fly” and towards system or “computer” control, which in turn allows for faster accommodation to shifting parameters during the surgery. More frequent sampling of power and fluidics parameters during the phaco cycle allows the computer to make rapid responses to changes in the micro environment. This automated system works to create efficiency in the phacoemulsification process enhancing safety and improving confidence. The greatest potential here will comes from the ability in the future to create a customized cataract surgery. If we are able to match phaco setting to a specific cataract grade before surgery it may result in less turbulence and trauma to remove the nuclei, the patient has clearer corneas post-op, less endothelial cell loss, lower possibility of significant complication, and an overall better experience with cataract surgery.
With an objective and reproducible grading system, such as the Pentacam Nucleus Grading System, the surgeon can then adjust the phacoemulsification system settings accordingly. The Pentacam is a rotating Scheimpflug camera which measures Scheimpflug images of the anterior eye segment. The Pentacam calculates a three dimensional mathematical model of the anterior segment to provides high resolution images of the interior of the eye and, among other things, a numerical grading of the lens density from 1 to 5. It seems logical that there should be adjustments of phaco setting at both ends of the cataract density spectrum from the system default settings. If all cataract surgical systems endeavor to create default setting based on objective cataract grading for the surgeon initial experience on their system this may result in a steeper learning curve and improved safety and efficiency. Further when “advances” in technology are introduced in different systems an objective system to grade the cataract may provide the proper baseline to assess its effect on Phaco efficiency. With the introduction of ELLIPS on the AMO WhiteStar Signature System we have an advanced mode of phaco energy delivery that is clinically proven to enhance phaco efficiency improving safety for the patient and confidence for the surgeon.