A new silicone phacoemulsification sleeve (Ridged Sleeve, ASICO) designed with a variety of novel features is enabling safe and efficient microcoaxial cataract surgery, said Takayuki Akahoshi, MD.
“The ideal phaco sleeve should provide sufficient irrigation, stable fluidics in the anterior chamber, good followability of nuclear fragments, and protect the incision from thermal damage,” said Dr. Akahoshi, director of ophthalmology, Mitsui Memorial Hospital, Tokyo.
“Experience with this new phaco sleeve shows it is fulfilling those criteria,” he added.
The sleeve is constructed of a thin, stiff silicone material so that it remains rigid and does not twist and collapse in the incision.
In addition, its outer surface is tumble-polished to facilitate smooth movement and prevent mechanical damage to the incision.
To improve followability, the end port of the sleeve is tapered to seal forward flow that would otherwise push nuclear fragments away from the phaco tip. It has three irrigation holes--two placed laterally and the third located on the inferior aspect of the sleeve.
“I measured the amount of irrigation and found that compared with two conventional phaco sleeves, the new sleeve provided more irrigation,” Dr. Akahoshi said.
“Flow from the third hole on the inferior aspect of the sleeve is directed toward the posterior capsule and provides added safety by pushing the capsule away from the phaco tip,” he said.
The sleeve also features six internal ridges, two each on opposing sides that run parallel to the shaft and one each across from each other at a position 90° to the large oval irrigation hole. The ridges prevent direct contact between the phaco tip and the sleeve where it is compressed in the incision.
“When squeezed in the incision, a conventional sleeve comes in direct contact with the phaco tip, and the heat transferred from the tip to the sleeve can cause damage to the incision,” he said.
The internal ridges in the new sleeve provide a barrier that prevents the sleeve from being pressed directly onto the phaco tip, he added.
Dr. Akahoshi demonstrated the performance of the new phaco sleeve with a video involving an eye with a dense, grade 4+ nuclear cataract removed with prechopping and a combination of torsional and longitudinal ultrasound.
“Most cataract cases can be done with cumulative dissipated energy less than 10, but the CDE for the case was almost 40,” he said. “Using a conventional phaco sleeve, severe damage to the incision would be likely.”