ABSTRACT
Objective To investigate the characteristics and possibility of using an image analyzer-aided method to count axotomized retinal ganglion cells (RGCs). Methods The left optic nerves of 18 rats were transected intraorbitally and a piece of gelform soaked in 5% fluorogold was applied to the ocular stump to retrogradely label the surviving RGCs. All animals were executed 2, 7 or 14 days after the operation (n=6 for each time point), respectively. The left retinae were removed, post-fixed and whole-mounted on the slides. The numbers of labeled RGCs were counted using both the conventional sampling method and image analysis, and compared statistically between the two methods. Results The number of surviving RGCs decreased sharply [(12 0663?9 089), (59 285?17 071) and (17 802?19 84) cells/mm 2 for image analyzer-aided method, and (118 237?7 898), (57 648?14 533) and (18 070?1 461) cells/mm 2 for conventional sampling method] when the survival time increased from 2 to 7 and 14 days. No significant difference was detected between the two groups at any corresponding time points. Conclusion The image analyzer-aided method is convenient, objective and reproducible, which can be used in the studies where counting RGCs is needed.