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Updated: May 8, 2026
Preparation and Immunofluorescence Staining of Bundles and Single Fiber Cells from the Cortex and Nucleus of the Eye Lens
Published on: June 9, 2023
Increase in lens capsule stiffness caused by vital dyes
Christos Haritoglou1, Stephan Mauell, Ricarda G Schumann
1From the Department of Ophthalmology (Haritoglou, Schumann, Wolf, Kernt) and the Department of Applied Physics and Center for NanoScience (Mauell, Benoit), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology (Henrich), University Hospital Basel, Basel, Switzerland.
Purpose:
To assess potential changes in lens capsule mechanical properties after staining with brilliant blue, indocyanine green (ICG), and trypan blue.
Setting:
Department of Ophthalmology and Applied Physics and Center for NanoScience, Ludwig-Maximilians-University, Munich, Germany.
Design:
Experimental study.
Methods:
Fifteen unstained lens capsules were dissected into 7 wedge-shaped parts. Three fragments were stained with brilliant blue 0.025%, ICG 0.05%, and trypan blue 0.06%, respectively, for 1 minute. Another 3 specimens were additionally illuminated using a standard light source. The seventh part served as an untreated control. All specimens were analyzed using atomic force microscopy (AFM) in contact mode with a scan rate of 0.6 Hz. Two scan regions of 10 μm × 10 μm were chosen, and stiffness was determined using AFM in a force spectroscopy mode. The force curves were performed with a data rate of 5000 Hz.
Results:
Staining of the samples resulted in an increase in tissue stiffness (brilliant blue: P<.001; ICG: P<.01; trypan blue: P<.05). Additional illumination after staining further increased tissue stiffness, but not significantly. Mean increase in the relative elasticity values were 1.61 ± 0.15 (SD) for brilliant blue, 2.04 ± 0.21 for brilliant blue with illumination, 1.63 ± 0.22 for ICG, 2.01 ± 0.22 for ICG with illumination, 1.23 ± 0.11 for trypan blue, and 1.39 ± 0.11 for trypan blue with illumination. In relation to unstained tissue, the relative elasticity of the stained tissue increased 1.2-fold after illumination.
Conclusion:
Staining significantly increased the mechanical properties of the human lens capsule.
Financial Disclosure:
No author has a financial or proprietary interest in any material or method mentioned.
