The effect of sodium hyaluronate and sodium chondroitin sulfate on the coagulation system in vitro

Collagen-Containing Fillers: Alone and in Combination

Soft tissue fillers may be injected into facial skin to ameliorate the appearance of fine lines and wrinkles, to augment lips and hollow cheeks, and to correct other imperfections, ultimately producing a more youthful appearance. Animal- and human-derived collagen implants have been used successfully for soft tissue augmentation for several years. Bovine collagen fillers were the most popular injectable implants for nearly 2 decades in the United States. Although these are still used, human bioengineered collagen products and fillers that contain hyaluronic acid have become available and are now more commonly used than the bovine-derived products. This article discusses the rationale for using the various types of fillers in combination and describes techniques for combining these fillers.

Comparison of the effect of Healon, Healon GV, Healon 5, Viscoat, and Ocucoat on platelet aggregation under in vitro conditions

PURPOSE

To study the effect of Healon, Healon GV, Healon 5, Viscoat, and OcuCoat on platelet aggregation under in vitro conditions.

METHODS

Ocular viscoelastic devices including Healon, Healon GV, Healon 5, Viscoat, and OcuCoat were studied to investigate the effect of these agents on platelet aggregation under in vitro conditions. The experiments were performed by using platelet-rich plasma with an aggregometer. Aggregation was induced with three different agonists including 5''-adeno-sinediphosphate (ADP), epinephrine (EPI), and collagen (Col ). The results were obtained as a percentage of maximal aggregation and compared with controls using one-way analysis of variance (ANOVA) test.

RESULTS

The tests with ADP as aggregating agent revealed that the percentages of maximal aggregation were a mean of 75 +/- 4.35% for ADP only, 67 +/- 4.35% for Healon, 59.33 +/- 3.51% for Healon GV, 70 +/- 3% for Healon 5, 58 +/- 3.46% for Viscoat, and 64 +/- 2% for OcuCoat. Kruskal-Wallis one-way ANOVA test revealed no significant decrease in the percentage of maximal aggregation for all tested substances. With EPI, aggregation was induced in all control samples with a mean of 80.66 +/- 2.08%. The mean percentage of maximal aggregation was 67 +/- 3% for Healon, 77.66 +/- 4.04% for Healon GV, 77 +/- 4% for Healon 5, 80.6 +/- 4.04% for Viscoat, and 65 +/- 5% for OcuCoat. Statistical analysis showed no significant difference. With collagen, maximum aggregation was 74 +/- 5.29% for controls, 65 +/- 4.35% for Healon, 54 +/- 2% for Healon GV, 51 +/- 2.64% for Healon 5, 59 +/- 2% for Viscoat, and 72.66 +/- 1.52% for OcuCoat. Kruskal -Wallis one-way ANOVA test revealed no significant change in the percentage of maximal aggregation for all tested substances in the experiments.

CONCLUSIONS

Ophthalmic viscosurgical devices like Healon, Healon GV, Healon 5, and Viscoat that contain glycosaminoglycans and OcuCoat that contains hydroxypropyl methylcellulose have inhibitory effects on platelet aggregation but the effect is not statistically significant and there is no difference among the ocular viscoelastic devices in regard to inhibitory effect on platelet aggregation.

Binding of hyaluronic acid to mammalian fibrinogens

We have postulated that the interaction of hyaluronic acid (HA), an extracellular matrix glycosaminoglycan, with fibrin is important during the early stages of wound healing and inflammation (J. Theor. Biol. 119:219; 1986), and have demonstrated the specific binding of 125I-labeled HA to human fibrinogen (J. Biol. Chem. 261:12 586; 1986). To determine whether HA binding is limited to human fibrinogen, we tested the ability of fibrinogens from various mammalian species to bind 125I-HA using a dot-blot assay. Increasing amounts of fibrinogen were adsorbed to nitrocellulose, and incubated with 125I-HA in the presence or absence of a 100-fold excess of nonradiolabeled HA to assess specific binding. In three independent experiments, the amount of 125I-HA bound/mg fibrinogen was determined from the slope derived by linear regression analysis of specifically bound 125I-HA versus protein concentration. A Student's t-test was performed to determine whether the slopes were statistically greater than zero. HA binding was considered statistically significant when P less than 0.05 was obtained by this analysis. Rabbit and dog fibrinogens significantly bound HA in all three trials. Baboon fibrinogen demonstrated significant HA binding in two of three trials. Pig, sheep and goat fibrinogens bound HA significantly in only one of three trials, whereas horse, rat and cow fibrinogens did not bind HA significantly at all. We conclude that fibrinogen from mammalian species other than human can specifically bind HA. The ability of fibrinogen to bind HA appears to correlate with an evolutionary divergence that separated human, baboon, dog, rabbit and rat from cow, pig, horse, goat and sheep.

Procoagulant effects of intraocular sodium hyaluronate (Healon) after phakic diabetic vitrectomy. A prospective, randomized study

A procoagulant effect was reported previously after injection of 0.50 to 0.75 ml of sodium hyaluronate (Healon) into the vitreous cavity at the end of phakic diabetic vitrectomies. A multicenter, randomized, prospective trial was done to study this effect. In the treatment group the media was clear in 50% of eyes in the immediate postoperative period compared with only 8% in the control group. At 2 to 6 weeks, there was no statistically significant difference between the two groups. The authors conclude that such sodium hyaluronate injection provides clear media in a significant number of eyes in the immediate postoperative period, potentially allowing thorough postoperative evaluation and early retinal photocoagulation if needed.