RESUMO
BACKGROUND: During pars plana vitrectomy, the retina is exposed to several iatrogenic risk factors, including excitotoxicity. A taurine-containing irrigation solution for pars plana vitrectomy (PURI PROTECT) has been developed and is claimed to have neuroprotective properties. METHODS: Retinal ganglion cells (RGC-5) and retinal whole mounts were incubated in standard irrigation solution (SIS) and SIS supplemented with 3 mM taurine (SIS-taurine). Excitotoxicity was induced by the addition of 8, 10, and 12 mM or 250 µM glutamate. Cell viability and cell survival were assessed by the MTT test and Annexin-V/propidium iodide flow cytometry. Whole mounts were stained with the Live/Dead staining assay. Pars plana vitrectomy with SIS or SIS-taurine was performed in rabbits. Animals were followed-up by electroretinography. RESULTS: RGC-5 incubated in SIS-taurine showed a 4.3-fold (P < 0.0005) better overall cell viability and an up to 8.5-fold (P < 0.05) increased cell survival under excitotoxic conditions compared with that incubated in SIS. Whole mounts incubated in SIS-taurine showed a 1.7-fold (P < 0.0005) and 1.6-fold (P < 0.0005) better cell survival under excitotoxic and nonexcitotoxic conditions, respectively. In the immediate postoperative period, b-wave amplitudes were significantly better in animals operated with SIS-taurine compared with control (P < 0.01). CONCLUSION: A taurine-containing irrigation solution may protect retinal ganglion cells against excitotoxicity.