RESUMO
PURPOSE: To compare the chemotactic activity induced by polymethyl methacrylate (PMMA), acrylic, and silicone intraocular lens (IOL) materials, regardless of the surgical and host factors. METHODS: The chemotactic effect of five different IOLs was studied using a modified multi-well Boyden chamber. Two different non-coated PMMA IOLs, a heparin-coated PMMA IOL, an acrylic IOL, and a silicone IOL were assessed. Each mean migration distance of the IOLs was compared with the others using Student's t test. RESULTS: All IOLs induced some amount of leukocyte chemotaxis. There was no statistically significant difference between the chemotactic activity of PMMA IOLs. However, chemotactic activity was significantly higher in acrylic (p<0.05) and silicone (p<0.05) IOLs compared to one of the PMMA lenses. CONCLUSIONS: This limited study has proven that chemotaxis assay is a useful tool to assess the biocompatibility of IOLs. The IOL material itself might attract inflammatory cells to its surface in the absence of surgical and host factors. As PMMA IOLs do not cause an increase in inflammatory reaction, they may be considered safe to use. Further improvement in chemical composition and surface characteristics of IOLs should reduce the inflammatory reaction and increase the biocompatibility and safety of IOLs.
Assuntos
Resinas Acrílicas , Quimiotaxia de Leucócito/fisiologia , Lentes Intraoculares , Polimetil Metacrilato , Elastômeros de Silicone , Humanos , Técnicas In VitroRESUMO
PURPOSE: Chronic ocular inflammation can be due to a disease process or to iatrogenic factors that attract inflammatory cells to the anterior chamber. This study was conducted to investigate the effect of commonly used ophthalmic preparations on leukocyte migration. METHODS: A modified multi-well Boyden chamber was used to study the chemotactic and chemokinetic effects of 33 commercial ophthalmic preparations. To determine whether the chemotactic effect was a property of the commercial ophthalmic preparation or other chemicals present in the products, experiments were also done with some common preservatives and excipients. RESULTS: Of the drugs, 14 (42.4%) showed chemokinetic and/or chemotactic activity and 19 (57.6%) had either no effect or decreased neutrophil migration. Of the preservatives and excipients, 5 (62.5%) were found to be chemotactic. Eleven of 14 chemotactic drugs (78.6%) and 8 of 19 non-chemotactic drugs (42.1%) were positive for at least one chemotactic excipient. The correlation between chemotactic ophthalmic preparations and the presence of a chemotactic excipient in their composition was significant (p < 0.05). CONCLUSIONS: Chemotactic activity was commonly found in commercial ophthalmic preparation. Furthermore, the presence of certain chemotactic preservatives and/or excipients was a contributing factor enhancing this property. Avoiding known chemotactic compounds or adjusting the intervals of the treatment may help to eliminate this iatrogenic component of the inflammatory process especially in patients with chronic ocular inflammation.