Abstract
Purpose: :
Retinal damage can be induced iatrogenically during vitreoretinal surgery. Risk factors are light-toxicity by endoillumination, chemical-toxicity by the irrigation-solution and mechanical damage by intraoperative alterations of the retina. PuriProtect is a new irrigation solution, which has already been introduced to the market. Its composition is basically the same like Balanced Salt Solution (BSS©, Alcon) except that 3mM taurine have been added. Taurine is essential for the survival of the retina and it is therefore presumably neuroprotective. However, up to now no investigations have been performed whether PURI PROTECT© is neuroprotective in comparison to standard irrigation solutions such as BSS®.
Methods: :
We investigated the effect of BSS® and PURI PROTECT® on the function and survival of retinal ganglion cells (RGC-5) in cell-culture (incubation for 2h with the irrigation solutions) and in whole-mount-preparations of bovine eyes (incubation for 2h with the irrigation solutions). For additional excitotoxic stress 8-, 10- and 12mM (RGC-5 cell culture) or 250µM glutamate (retinal whole mount) were added during incubation with the irrigation-solutions. To evaluate glycolysis, apoptosis and survival of RGCs MTT-test, FACS-analysis of Annexin-5 positive cells, Live/Dead staining and histopathology were performed.
Results: :
In the absence of excitotoxic stress there was no difference in glycolysis or apoptosis of RGC-5 cells when irrigated with BSS® or PuriProtect®. However, after induction of additional stress with 8-, 10- or 12mM glutamate a significant difference was observed in both tests. In the whole-mount-preparations PURI PROTECT® showed a significant protective effect even without the addition of 250µM glutamate, which could be enhanced by adding 250µM glutamate.
Conclusions: :
PURI PROTECT® irrigation solution has neuroprotective properties in comparison to BSS®, especially in preventing glutamate induced excitotoxicity. Elevated glutamate-levels can be encountered during hypoxia, in retinal detachment, during endoillumination or other conditions of cellular stress. Therefore PuriProtect® may prevent iatrogenically induced death of retinal ganglion cells during vitrectomy or other states of ongoing damage e.g. during retinal detachement.
Keywords: vitreoretinal surgery • neuroprotection • taurine