Retinal nerve fiber layer (RNLF) analysis by scanning laser polarimetry (SLP) has been developed to facilitate both diagnosis and follow up in glaucoma. No studies are yet available on the effectiveness of SLP for following RNFL thickness over time. A major difficulty is the slow reduction of RNFL thickness in glaucoma. Acute retrobulbar optic nerve injury causes rapid loss of optic nerve axons. We therefore studied eyes of five patients with injury to one optic nerve in order to evaluate the usefulness of SLP in documenting RNFL loss over time and to analyze the time course of the evolving descending optic atrophy. All patients showed acute and severe visual loss and normal initial fundoscopic findings. Repeated measurements of the RNFL using SLP were performed: the first examination within one week of injury, and subsequent measurements in roughly weekly intervals. In all eyes marked decrease in RNFL thickness, mainly within the first seven to eight weeks, was demonstrated. Two eyes showed initial increase in RNFL thickness before the expected decrease occurred. Compared to a previous study using red-free photographs, SLP showed RNFL loss earlier in the course of descending atrophy. In conclusion, SLP is able to document the RNFL loss following acute injury to the retrobulbar optic nerve over time and it seems to do so at a relatively early stage. Of major interest would be to show if SLP can help to monitor glaucomatous optic nerve damage in individual patients over time as well.