For gross documentation, lenses from 3-week-old mice were
enucleated under a dissecting microscope (MZ APO; Leica, Heidelberg,
Germany) and photographed at ×20 magnification. For detailed
histologic analysis, eyes from 3-day and 3-week-old mice were fixed for
24 hours in Carnoy’s solution, dehydrated, and embedded in paraffin or
plastic medium (JB-4Plus; Polysciences, Inc., Eppelheim, Germany)
according to the manufacturer’s procedure. Sectioning was performed
with an ultramicrotome (Ultratom OMU3; Reichert, Walldorf, Germany).
Serial transverse 2-μm sections were cut with a dry glass knife and
collected in water drops on glass slides. After drying, the sections
were stained with methylene blue and basic fuchsin. Paraffin-embedded
sections were stained by hematoxylin-eosin or propidium iodide. The
sections were evaluated using a light microscope (Axioplan, Zeiss).
Images were acquired by means of a scanning camera (Progress 3008;
Jenoptik, Jena, Germany) equipped with a screen-capture program (KS100;
Carl Zeiss Vision, Hallbergmoos, Germany) and imported into an
image-processing program (Adobe Illustrator 9.0 or Photoshop 6.0;
Adobe, Unterschleissheim, Germany).