OR WAIT 15 SECS
An ophthalmic viscosurgical device of 2.3% sodium hyaluronate (Healon 5, Abbott Medical Optics) makes one ophthalmologist's prechopping-assisted phacoemulsification technique safer and easier, he says.
Warminster, PA-For surgeons who favor or are interested in performing a prechopping-assisted phacoemulsification technique, a 2.3% sodium hyaluronate ophthalmic viscosurgical device ([OVD]; Healon 5, Abbott Medical Optics) offers a unique tool that enables the efficacy and safety of the chopping procedure, according to Francis J. Clark, MD.
"Mechanically dividing the nucleus with prechopping is well recognized for its benefit of reducing the amount of ultrasound energy used during the cataract procedure," said Dr. Clark, who is in private practice outside of Philadelphia and a member of the medical advisory board, Wills Eye Surgery Center of Bucks County, Warminster, PA. "However, some surgeons who attempt this approach abandon it because they find themselves unable to . . . rotate the lens and divide the nucleus [adequately].
"[The agent] has space-occupying ability that distinguishes it from all other OVDs and that allows it to be a very useful surgical adjunct for making prechopping much safer and easier, even in eyes with a very dense lens," Dr. Clark added.
Complete hydrodissection is a critical prerequisite to the prechopping technique, so careful attention must be given to making sure that the nucleus is entirely freed from its attachments so that it can be rotated after splitting, according to Dr. Clark. In a routine case in which the nucleus is not too dense, the benefit of using this OVD is that it helps to push back the lens, thereby ensuring adequate room for instrument manipulation during chopping and rotation. The OVD also remains in the eye as the lens is rotated, he said.
When a surgeon is faced with a dense cataract, he or she first prolapses the nucleus out of the capsular bag using a wider capsulorhexis than usual and gentle hydrodissection. After the nucleus is prolapsed, the agent is used through the sideport incision to fill the capsular bag, pushing the bag posteriorly and allowing the use of a second instrument, such as a Drysdale, to apply counterpressure as the nucleus is divided in half with the prechopper.
"The prechopper is introduced into the eye through the main incision, impales the nucleus, and easily cracks the densest nuclei in half, with the help of the Drysdale offering posterior support to the nucleus," Dr. Clark said. "[The OVD] serves well to maintain space by pushing back on the capsular bag while also providing protection."
Use a thin shell
To ensure an adequately sized capsulorhexis, he uses the OVD together with 1.0% sodium hyaluronate (Healon, Abbott Medical Optics) in a soft-shell technique, placing a thin shell of the latter OVD on the anterior capsule surface.
"The [2.3% sodium hyaluronate OVD] filling the anterior chamber is helpful for pushing the capsular bag backward and creating space, [whereas] the presence of [1.0% sodium hyaluronate] immediately over the anterior capsule eliminates issues with opposing vector forces that can lead to a small capsulorhexis," he said.
Although the 2.3% sodium hyaluronate OVD is fairly readily evacuated from the eye during phaco, Dr. Clark said that this quality does not represent a limitation to its use, because he is working with a prechopped lens.
"After prechopping, my phaco time is short, and the [2.3% sodium hyaluronate OVD] stays in the eye long enough for me to complete the lens removal portion of the procedure," he concluded.