Jackson, TN—The Toyos AquaChop procedure, which is a new technique for cataract extraction, takes advantage of the special properties of the AquaLase liquefaction device (Alcon, Fort Worth, TX).
Jackson, TN-The Toyos AquaChop procedure, which is a new technique for cataract extraction, takes advantage of the special properties of the AquaLase liquefaction device (Alcon, Fort Worth, TX).
AquaLase is advantageous because during the procedure there is no mechanical motion in the eye, which allows a second instrument to touch the tip without harm. This contrasts with phacoemulsification because if the metal phaco tip approaches the posterior capsule the capsule may rupture, while the polymer AquaLase tip will not cause a rupture.
"Aqualase is very different from phacoemulsification. With AquaLase there is no vibrating tip in the eye, but rather heated fluid pulses at 50 pulses per second. This allows the AquaLase tip to go where the phaco tip cannot. There is also no corneal edema or iris damage with AquaLase as with phaco," Dr. Toyos said.
Dr. Toyos explained that he developed the Toyos AquaChop technique because of the need for a procedure that he could use to extract very dense cataract material.
"With AquaLase, +1 to +2 cataracts can be easily removed with any technique, such as divide-and-conquer, bowling, flip, or chop. However, with harder nuclei, when doing a divide-and-conquer technique or grooving, the extraction becomes difficult," he explained.
In his cataract population, many patients have +3 and denser cataracts, which necessitated a different technique in order to use AquaLase.
With denser cataracts, he explained, the nuclear fragments are pushed away from the tip during the AquaLase procedure. In this case, he uses a second instrument to keep the fragments near the tip.
"The advantage is that because there is no vibrating tip in the eye, the second instrument can be used to help break up the cataract. By using the fluid pulses, the surgeon can break up the cataract and keep it on the tip," Dr. Toyos said.
When he performs AquaChop, he flips the nucleus on its side and uses the second instrument to crack the nucleus with high vacuum. He does not apply pulses until he is certain that the nuclear fragment is on its tip. He then applies force if the cataract is brunescent.
The second instrument he designed and uses is the Toyos AquaChopper (Rhein Medical, Tampa, FL). He first cracks the lens in half and uses the AquaChopper to keep the fragment on the tip. He avoids using bursts until the fragment is securely on the tip and the AquaChopper is behind it. He uses 100% magnitude and high vacuum with this technique, he noted, instead of a gradual rise in magnitude or vacuum that is available in the AquaLase device.
"I also have not been switching handpieces from the AquaLase handpiece to the irrigation/aspiration handpiece. I remove the nuclear fragments and then use AquaLase to remove the cortex. This saves time. When it is time to wash the posterior capsule, I use AquaLase without having to switch," he explained.
Dr. Toyos and colleagues have been conducting endothelial cell count studies and they found that there is a correlation between the number of pulses used and corneal endothelial loss.
"That number is about 2,000 pulses. Fewer than 2,000 pulses is optimal," he said. In early cases, he used about 8,000 pulses; now after performing more than 1,000 cases, he can remove most cataracts using about 500 to 1,000 pulses.