Naturally occurring lipid keratopathy in the dog has been
investigated using a variety of examination techniques. The same
procedures have also been followed for a group of normal dogs
matched to the clinical cases by age, sex and breed and for a third
group of unmatched, normal, animals.
Investigations have included general clinical and ophthalmoscopic
examination and detailed examination of the anterior segment,
including tonometry, temperature measurement and fluorescein
angiography. Laboratory examination has largely concentrated on
serum lipid and lipoprotein analysis.
A number of microscopic methods have been applied to normal and
diseased corneas. A comprehensive selection of histochemical
techniques for identification of lipids have been used in
conjunction with light, polarising, interference contrast and phase
contrast microscopy. The physical properties of lipids have been
explored using squash or imprint preparations, a heated microscope
stage and polarised light (with a mica plate and a first order
red gypsum accessory plate). A variety of other non-1ipid methods
have also been used.
Ultrastructural studies complemented those of light microscopy,
employing both scanning electron microscopy and transmission
electron microscopy and utilising a limited number of
ultrahistochemical staining techniques with the latter.
The results of this study indicate that lipid keratopathy may
be associated with a variety of conditions involving the anterior
segment and that abnormalities of the serum lipids and lipoproteins
can often be demonstrated in affected animals. These findings are
of significance for diseases of lipid metabolism in other species.