One surgeon's preference for an ophthalmic surgical device (OVD) of 1.6% sodium hyaluronate (Amvisc Plus, Bausch & Lomb) was reinforced by a study that found it superior to another OVD during phaco and OVD removal.
John D. Hunkeler, MD, medical director, Hunkeler Eye Institute, and chairman, Department of Ophthalmology, University of Kansas School of Medicine, Kansas City, KS, said that 1.6% sodium hyaluronate had been his preferred OVD for cataract surgery for many years but that he decided to undertake a formal comparison of its characteristics compared with another OVD, the viscous-dispersive product of 4% chondroitin sulfate/1.65% sodium hyaluronate (DisCoVisc, Alcon Laboratories) (Cataract & Refractive Surgery Today, May 2009).
The study randomly assigned 20 consecutive eyes undergoing phaco to surgery using either of the two OVDs. Dr. Hunkeler's evaluations considered his satisfaction with each product during its initial insertion, capsulorhexis, phaco, IOL implantation, and removal at the end of the case.
Both products performed exceptionally well during capsulorhexis and IOL implantation, he said. Differences favoring 1.6% sodium hyaluronate in the other categories were observed, however, and this OVD particularly outperformed 4% chondroitin sulfate/1.65% sodium hyaluronate during phaco and in removal after IOL implantation.
"My experience has been that [1.6% sodium hyaluronate] offers a unique combination of dispersive and cohesive properties that makes it perform well during all stages of lens removal surgery. In general, it has all of the attributes of an ideal OVD because it provides excellent tissue protection, separates tissue planes and maintains space, affords good intraocular visibility, and stays in the eye during phaco but is easy to remove at the end of the procedure," Dr. Hunkeler said. "[The 4% chondroitin sulfate/1.65% sodium hyaluronate product] is described as a viscous-dispersive OVD, but my comparative study shows that it performs differently [from 1.6% sodium hyaluronate]. My study strengthened my opinions on the excellent overall performance and ease of use of [1.6% sodium hyaluronate] and provided me with added confidence to continue using it as my OVD of choice for all my routine cataract procedures."
Although no problems were encountered during phaco in cases performed with 1.6% sodium hyaluronate, needle clogging occurred during initial sculpting and/or debulking of the anterior surface of the lens in several cases using 4% chondroitin sulfate/1.65% sodium hyaluronate. In addition, whereas the nuclear fragments presented readily to the phaco tip using 1.6% sodium hyaluronate, with 4% chondroitin sulfate/1.65% sodium hyaluronate, a tendency was observed for the nuclear pieces to be attracted toward the chamber angle to the right of the phaco tip and lodge there.
"Based on their location in relation to my dominant hand, accessing these pieces added unnecessary time and effort to the surgery," Dr. Hunkeler said. This phenomenon associated with the viscous-dispersive OVD use also increases the possibility that small but significant nuclear fragments will be sequestered in the angle at the end of the procedure. Therefore, extra care and time had to be taken to look for and remove any such fragments, Dr. Hunkeler said.
Further, although 1.6% sodium hyaluronate readily was evacuated at the end of the case, OVD removal was more laborious and required more time in the procedures using 4% chondroitin sulfate/1.65% sodium hyaluronate.
"Thorough OVD removal at the end of the case is an essential element for achieving a good surgical outcome and particularly when implanting the newer single-piece and accommodating IOLs. It is consistently easy using [1.6% sodium hyaluronate]," Dr. Hunkeler said.