Related Experiment Videos
Calcium cataract: a model for optical anisotropy fluctuations
F A Bettelheim1, C Qin, J S Zigler
1Chemistry Dept., Adelphi University, Garden City, NY 11530, USA.
Experimental Eye Research
|February 1, 1995
Summary
High calcium levels in rat lenses caused cataracts by affecting vimentin proteins. This led to increased light scattering and lens opacity, indicating changes in optical properties during cataract development.
Area of Science:
- Ophthalmology
- Biochemistry
- Cell Biology
Background:
- Cataracts are a leading cause of blindness.
- Lens opacity is associated with changes in protein structure and light scattering.
- The role of calcium and specific proteins like vimentin in cataractogenesis requires further elucidation.
Purpose of the Study:
- To investigate the effect of high calcium concentration on rat lens organ culture.
- To examine the changes in vimentin protein solubility and optical properties during induced cataract formation.
- To correlate the presence of vimentin with lens turbidity and birefringence.
Main Methods:
- Rat lenses were cultured in media with 20 mM calcium.
- Protein fractions were analyzed for vimentin content using urea solubility.
- Polarized light scattering was used to measure optical anisotropy.
- Birefringence was assessed in lens sections.
Main Results:
- Lenses cultured in high calcium medium developed cataracts.
- Vimentin was absent in the urea-soluble protein fractions of cataractous lenses.
- Increased I+/Iparallel scattering intensity ratios indicated enhanced optical anisotropy fluctuations.
- Turbidity was linked to vimentin disappearance and increased lens birefringence.
Conclusions:
- Elevated calcium levels induce cataract formation in rat lenses.
- Vimentin loss from soluble fractions is a key event in calcium-induced cataractogenesis.
- Changes in optical anisotropy and birefringence are significant indicators of cataract development.