Quantification of residual ophthalmic viscosurgical device after irrigation/aspiration in experimental cataract surgery in vitro.

PURPOSE: To determine the distribution and quantity of ophthalmic viscosurgical device (OVD) retained in the lens capsular bag after irrigation/aspiration (I/A) in experimental cataract surgery. SETTING: Department of Ophthalmology, Kashiwa Hospital, Jikei University School of Medicine, Japan. DESIGN: Experimental study. METHODS: Fifteen freshly enucleated porcine eyes were used. Sodium hyaluronate 1.0% (Healon) was mixed with a fixed concentration of silica nanoparticles encapsulating fluorescein isothiocyanate (labeled OVD), and it was injected separately into the capsular bag and injector cartridge for intraocular lens (IOL) insertion. After a 3-piece IOL (YA-60BBR) or a 1-piece IOL (iSert 255) was implanted within the capsular bag, OVD was removed by thorough I/A. Eyes that were injected with the labeled OVD into the capsular bag without IOL insertion were used as controls. The distribution of residual OVD in the capsular bag was observed under ultraviolet irradiation using Miyake-Apple view. Then, the excised capsular bag was dissolved in hydrogen fluoride, and silica concentration was measured quantitatively by elemental analysis. RESULTS: The quantity of residual OVD in the capsular bag was 243.1 µg ± 1.3 (SD) in the 3-piece IOL-implanted group, 383.8 ± 11.1 µg in the 1-piece IOL-implanted group, and 99.0 ± 1.3 µg in the control group. In the 1-piece IOL-implanted eyes, OVD in the form of clumps tended to remain near the center of the optic on the posterior side, and the quantity of residual OVD was significantly greater than in 3-piece IOL-implanted eyes (P < .05). CONCLUSION: The quantity of residual OVD after I/A could be determined indirectly using labeled OVD, and the quantity was significantly greater in 1-piece IOL-implanted eyes than in 3-piece IOL-implanted eyes.

Corneal endothelial cell coating during phacoemulsification using a new dispersive hyaluronic acid ophthalmic viscosurgical device.

PURPOSE: To compare the corneal endothelial coating of a new hyaluronic acid ophthalmic viscosurgical device (OVD) with dispersive properties with that of a standard hyaluronic acid OVD with cohesive properties. SETTING: David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University of Heidelberg, Germany. DESIGN: Experimental study. METHODS: The corneal endothelial cell coating of a new dispersive OVD (sodium hyaluronate 3% [Healon Endocoat]) and a standard cohesive hyaluronic acid OVD (sodium hyaluronate 1.4% [Healon GV]) as well as their combination using the soft-shell technique were evaluated. All OVDs were stained with fluorescein. Each of the 3 test groups comprised 10 porcine eyes. Cataract surgery was performed with identical phacoemulsification settings and time frames. Afterward, the cornea was trephined and a photograph taken of the endothelial side under blue light. The corneal coating with OVD was evaluated using planimetric image-analysis software. RESULTS: The least endothelial coating was in the cohesive group (71%), while the dispersive group had statistically significantly higher adherence to the endothelium (87%) (P=.0009). The greatest endothelial coating was in the soft-shell technique group (93%); however, the difference between that group and the dispersive group was not statistically significant (P=.0962). CONCLUSION: The new dispersive hyaluronic acid OVD with a low molecular weight showed a greater adherence to the endothelial surface than the standard cohesive hyaluronic acid OVD with a higher molecular weight. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Potential role of hyaluronic acid on bone in osteoarthritis: matrix metalloproteinases, aggrecanases, and RANKL expression are partially prevented by hyaluronic acid in interleukin 1-stimulated osteoblasts.

OBJECTIVE: To determine the effect of hyaluronic acid (HA) on proteolytic enzymes and bone remodeling mediators induced by interleukin 1ß (IL-1ß) and related to cartilage catabolism in murine osteoblasts. METHODS: Osteoblasts were obtained from Swiss mice and cultured for 3 weeks. HA-treated osteoblasts were incubated with 100 µg/ml HA during the last week of culture, then stimulated with IL-1ß (10 ng/ml) for 24 h. The expression of matrix metalloproteinases 3 and 13 (MMP-3 and MMP-13), ADAMTS-4 and ADAMTS-5, tissue inhibitor of metalloproteinases (TIMP), osteoprotegerin, and receptor activator of nuclear factor-κB ligand (RANKL) was determined by real-time polymerase chain reaction. MMP-3 and MMP-13 release was assessed by Western blot analysis. RESULTS: IL-1ß increased the mRNA levels of MMP-3 and MMP-13 and ADAMTS-4 and ADAMTS-5 and release of MMP-3 and MMP-13. Seven days of HA treatment significantly prevented the IL-1ß-increased mRNA levels of MMP-3 (-61%, p < 0.01), MMP-13 (-56%, p < 0.01), ADAMTS-4 (-58%, p < 0.05), ADAMTS-5 (-52%, p < 0.01), and RANKL (-49%, p < 0.05), but not TIMP. As well, IL-1ß-induced production of MMP-3 and MMP-13 was inhibited, by 27% (p < 0.01) and 40% (p < 0.01), respectively. CONCLUSION: In an inflammatory context in murine osteoblasts, HA can inhibit the expression of MMP and ADAMTS. Because HA can counteract the production of these mediators in chondrocytes, its beneficial effect in osteoarthritis may be due to its action on cartilage and subchondral bone.

The Ultrachopper tip: a wound temperature study.

PURPOSE: To determine the thermal characteristics of the Ultrachopper and its thermal properties in varied viscosurgical substances. DESIGN: Experimental study. PARTICIPANTS: Not applicable. METHODS: The Ultrachopper (Alcon, Inc) tip with the Infiniti (Alcon, Inc) handpiece was attached to a thermistor and placed in a test chamber filled with either an ophthalmic viscosurgical device (OVD) or balanced salt solution (BSS). The thermistor allowed for continuous monitoring of temperature from baseline and the change that occurred over 60 seconds of continuous run time. RESULTS: Mean maximum temperature in each OVD exceeded 50°C over the first 25 seconds of continuous run time. The mean maximum temperature was statistically significantly higher with all OVDs (p < 0.0001) when compared with BSS. A small but statistically significant difference in mean maximum temperature was shown between Healon 5 (AMO, Inc) and Viscoat (Alcon, Inc) (p < 0.05). The linear increase in temperature was statistically significantly different with all OVDs compared with BSS (p < 0.0001). CONCLUSIONS: The thermal properties of the Ultrachopper tip demonstrate a heat-generating capacity that achieves published thresholds for risk for wound burn.

A review of the metabolism of 1,4-butanediol diglycidyl ether-crosslinked hyaluronic acid dermal fillers.

BACKGROUND: Cosmetic procedures are growing ever more common, and the use of soft tissue fillers is increasing. Practicing physicians need to be aware of the biological behavior of these products in tissue to enable them to respond to any safety concerns that their patients raise. OBJECTIVES: To provide an overview of the metabolism of 1,4-butanediol diglycidyl ether (BDDE)-crosslinked hyaluronic acid (HA) dermal fillers and to examine the safety of the resulting byproducts. METHODS: A review of available evidence was conducted. RESULTS: After reaction with HA, the epoxide groups of BDDE are neutralized, and only trace amounts of unreacted BDDE remain in the product (<2 parts per million). When crosslinked HA, uncrosslinked HA, and unreacted BDDE degrade, they break down into harmless byproducts or into byproducts that are identical to substances already found in the skin. CONCLUSION: Clinical and biocompatibility data from longer than 15 years support the favorable clinical safety profile of BDDE-crosslinked HA and its degradation products. Given the strength of the empirical evidence, physicians should be confident in offering these products to their patients.

Assessment of adequate removal of ophthalmic viscoelastic device with irrigation/aspiration by quantifying intraocular lens 'Judders'.

BACKGROUND: To assess the efficacy of 'Judders' as a technique reflecting adequacy of removal of ophthalmic viscoelastic device in cataract surgery. DESIGN: Prospective, consecutive, single surgeon study. PARTICIPANTS: Cohort of 223 patients undergoing phacoemulsification. METHODS: 'Judders' are periodic, abrupt, horizontal displacements of the intraocular lens causing balanced salt solution to displace retropseudophakic ophthalmic viscoelastic device. The number of 'Judders' was correlated with axial length, anterior chamber depth, and preoperative and postoperative intraocular pressure. MAIN OUTCOME MEASURES: Number of 'Judders', axial length, anterior chamber depth, day 1 postoperative intraocular pressure. RESULTS: The mean number of 'Judders' was 3.2. There was a positive association between the number of 'Judders' and axial length, but not between number of 'Judders' and anterior chamber depth. Mean preoperative intraocular pressure was 14.5 mmHg; mean day 1 postoperative intraocular pressure was 15.6 mmHg. Intraocular pressure rose in 47% of cases. In six cases (5%), intraocular pressure rose greater than 10 mmHg (range 11-23 mmHg) from the preoperative level. CONCLUSIONS: Aspirating ophthalmic viscoelastic device with the irrigation/aspiration tip posterior to the intraocular lens may be associated with the risk of a posterior capsule tear. Maintaining the irrigation/aspiration tip anterior to the intraocular lens may offer a significant safety advantage. The number of 'Judders', usually 3-4, appears to be a safe and reliable end-point of complete ophthalmic viscoelastic device removal. There were significantly more 'Judders' in eyes with a longer axial length. The safety and efficacy of 'Judders' are reflected by the stable mean postoperative intraocular pressure.

[Functional metabolic characteristics of sodium hyaluronate in mammal organism].

In the review data concerning functional metabolic characteristics of sodium hyaluronate in mammal organism, as well as autologous results concerning the study of its intraarticular action on metabolism of conjunctive tissue in the conditions of experimental arthritis in rabbits are given.

Adhesive retention of sodium hyaluronate ophthalmic viscosurgical devices in an acrylic tube model and in porcine-eye corneal endothelium with different irrigation rates.

PURPOSE: To evaluate the influence of irrigation rates on the adhesive retention of sodium hyaluronate ophthalmic viscosurgical devices (OVDs) by observation in an acrylic tube system designed to model the epithelial wall and in a porcine-eye experiment. SETTING: Kohseichuo Hospital, Tokyo, Japan. METHODS: Commercial sodium hyaluronate OVDs differing in molecular weight were visualized with fluorescein powder. Their adhesive and kinetic characteristics at 2 irrigation rates were visually observed in the acrylic tube model and in a porcine eye under phacoemulsification and aspiration. RESULTS: In the acrylic tube model, the mean retention time of the low-molecular-weight sodium hyaluronate increased from 2.3 seconds under 78 mL/min irrigation to 27.9 seconds under 45 mL/min irrigation. In the porcine eye, phacoemulsification retention of the same OVD on the corneal endothelial cells was also longer under the low irrigation rate of a 2.2 mm incision than under the higher rate of a 3.5 mm incision. CONCLUSION: The stable retention of low-molecular-weight sodium hyaluronate in the acrylic tube model at the low irrigation rate corresponded closely with that observed in the porcine eye. This indicates that low-molecular-weight sodium hyaluronate with the low irrigation rates used in procedures such as microincision cataract surgery may effectively protect corneal endothelial cells against surgical risks.