Abstract
Purpose: :
Information available in the literature regarding structural features seen within the core of advanced cataractous lenses using scanning electron microscopy (SEM) is minimal. SEM of fiber cells affords 3D visualization of structures seen using the higher resolution method of transmission electron microscopy and yields important comparative information. In particular, stereo imaging of multilamellar bodies (MLBs) to understand their 3D structure would be valuable to the understanding of their light scattering properties.
Methods: :
Nuclei from advanced cataracts (n=10; ages 49-75 yrs) obtained following extracapsular cataract extractions at the LV Prasad Eye Institute were fixed and prepared using established techniques for study using the JEOL JSM 6300 SEM. Previously studied characteristics, including changes in fiber cell arrangement, membrane topography and evidence of damage to structures that could lead to increased light scattering, were investigated and compared with less advanced cataracts and transparent lenses from the USA.
Results: :
Scanning electron micrographs revealed structural features that were similar to comparable regions of less advanced cataracts and transparent lenses from the USA. Micrographs revealing the 3D structure of rarely seen MLBs, which previously have only been described using other microscopy methods, were obtained for the first time. Stereoscopic views suggested that they were roughly spherical and had a different surface topography compared to the adjoining fiber cells. No other specific damage was found on the exposed surfaces of the bisected cores of these opaque nuclei that could directly relate to the observed opacity.
Conclusions: :
Advanced age-related nuclear cataracts from India are not appreciably different from the cataracts studied in the USA with respect to their SEM structure. The main advantage of this technique in visualizing structural features and alterations in 3D was utilized to study the cores of advanced cataracts from blind subjects, revealing unique views of MLBs.
Keywords: cataract • microscopy: electron microscopy • aging