• bimodal atomic force microscopy;
  • inner limiting membrane;
  • soft tissues;
  • triamcinolone acetonide;
  • vital dyes


Bimodal imaging is utilized to characterize the topography of human tissue samples. The deposition of triamcinolone acetonide (TA) on various surfaces – including surgical human inner limiting membrane (ILM) samples and collagen fibrillar sheets – was studied. Changes in composition were well defined with bimodal imaging when TA deposition was examined on mica. TA sedimentation resulted in observable changes in ILM topography when compared to collagen fibrillar sheets. The heterogeneous chemical and topographical features of the ILM tissues promoted the TA crystallization compared to the flatter and homogeneous collagen surfaces. Higher spatial resolution was achieved by imaging ILM samples in the new bimodal imaging mode. The most apparent difference was observed in the imaging of ILM samples which had been exposed to the steroid TA. The study demonstrated the usefulness of bimodal imaging to evaluate tissue samples.