Mixed polymeric systems: New ophthalmic viscosurgical device created by mixing commercially available devices.
To evaluate the rheological properties of mixtures of different commercially available ophthalmic viscosurgical devices (OVDs) containing sodium hyaluronate and chondroitin sulfate.



Eye Clinic, University of Trieste, Trieste, Italy.



Laboratory study.



Blends were obtained combining a superviscous cohesive OVD (Healon GV [sodium hyaluronate 1%]) and a medium-viscosity dispersive OVD (Viscoat [sodium hyaluronate 3.0%-chondroitin sulfate 4.0%]). The 2 substances were combined in different ratios, and the rheological characteristics were analyzed to find the optimum proportion. A new viscous dispersive OVD, Discovisc (hyaluronic acid 1.6%-chondroitin sulfate 4.0%) was evaluated for comparison. The storage modulus, loss modulus, crossover point, complex viscosity, shear viscosity, and pseudoplasticity were studied.



The rheological properties of the mixed solution (1:1 and 3:1) showed intermediate characteristics in comparison with the 2 original substances, characterized by a viscosity comparable to that of the superviscous cohesive OVD, but at a higher shear rate (similar to the medium-viscosity dispersive OVD). The new viscous dispersive OVD performed similarly to the medium-viscosity dispersive OVD at low shear rates but was comparable to the superviscous cohesive OVD at high shear rates.



The mixture of dispersive and cohesive rheological properties in a single OVD might be an advantage during cataract surgery.
From the Eye Clinic (Tognetto, D'Aloisio, Cecchini) and the Department of Engineering and Architecture (Lapasin), University of Trieste, Trieste, Italy.
Daniele
D
Tognetto
From the Eye Clinic (Tognetto, D'Aloisio, Cecchini) and the Department of Engineering and Architecture (Lapasin), University of Trieste, Trieste, Italy. Electronic address: paolo.cecchini@ymail.com.
Paolo
P
Cecchini
From the Eye Clinic (Tognetto, D'Aloisio, Cecchini) and the Department of Engineering and Architecture (Lapasin), University of Trieste, Trieste, Italy.
Rossella
R
D'Aloisio
From the Eye Clinic (Tognetto, D'Aloisio, Cecchini) and the Department of Engineering and Architecture (Lapasin), University of Trieste, Trieste, Italy.
Romano
R
Lapasin
D002387:Cataract Extraction; D002809:Chondroitin Sulfates; D004338:Drug Combinations; D006801:Humans; D006820:Hyaluronic Acid; D018918:Phacoemulsification / Q000295:instrumentation; D011108:Polymers; D014783:Viscosity
D004338:Drug Combinations; D011108:Polymers; C501944:chondroitin sulfate, sodium hyaluronate drug combination; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates