Purpose: Several iatrogenic risk factors during pars plana vitrectomy (PPV) could cause damage to the retina. One mechanism is excitotoxicity. Therefore, neuroprotective irrigation solutions would be desirable.
Methods: Retinal ganglion cells (RGC-5) and retinal whole mounts were incubated in standard irrigation solution (SIS) and Dulbecco's Modified Eagle Medium (DMEM). Cell viability, cell amount, cell survival and caspase 3/7 activity were measured by MTS-Test, crystal-violet staining, Annexin-V/PI flow cytometry and caspase 3/7 activity assay, respectively. The morphology and the function of retinal whole mounts were analysed by Live/Dead(TM) staining and by the b-wave and a-wave of the electroretinogram (ERG).
Results: Under excitotoxic conditions (10 mM and 12 mM glutamate) RGC-5 cells incubated in SIS showed a statistically significant reduction in cell viability, cell amount, cell survival and caspase 3/7 activity compared to DMEM. Furthermore, the incubation of retinal whole mounts in DMEM resulted in a significant decrease of cell death under excitotoxic (250 μM glutamate) and standard conditions compared to SIS. ERG b-wave recordings revealed good functional preservation of retinal whole mounts in DMEM, but loss in SIS.
Conclusion: DMEM seems to support retinal cells very well and to be strongly protective against excitotoxicity. Therefore, DMEM may be considered as possible neuroprotective irrigation solution for PPV.