Moderately cohesive ophthalmic viscosurgical devices offer desired performance traits
She presented findings from a study evaluating the OVD behaviour and endothelial cell loss in groups of 20 eyes each operated on using PhysioVisc Integral (PhysIOL, Liège, Belgium), Amvisc Plus (Bausch + Lomb Surgical, Greater London, UK) or Z-Hyalin Plus (Carl Zeiss Meditec, Jena, Germany). All surgeries were performed using the same phacoemulsification platform (Stellaris, Bausch + Lomb) and a bimanual microincision technique involving two 1.2 mm incisions and with enlargement of one incision to 1.7 mm for IOL implantation.
"When surgeons perform cataract surgery through self-sealing incisions, the OVD is expected to maintain the anterior chamber depth so as to facilitate the capsulorhexis," she explained. "However, while the OVD needs to provide space and tissue protection, if it is not spontaneously expelled during surgical manoeuvers, particularly during hydrodissection, there is a risk of overpressurisation that can lead to capsule rupture.
"The study results show that each of these OVDs offers behaviour that is in line with [the] surgeon's expectations and that the OVDs provided good protection for the corneal endothelium," Dr Deidier added.
As moderately cohesive OVDs, all three products evaluated in the study have high viscosity, strong elasticity and strong pseudoplasticity that allow easy injection through a 27-gauge cannula and removal at the end of the procedure, even with 1.2 mm microincision instruments, noted Dr Deidier.
The three study groups were similar with respect to mean patient age (72 to 76 years), cataract grade (about LOCS III) and preoperative ECC measured by specular microscopy (about 2400 cells/mm2). Based on measurements performed at a month after surgery, mean ECC loss was 1% in eyes operated on with PhysioVisc Integral, 1.09% in the Amvisc Plus group and 1.01% for the Z-Hyalin Plus procedures.