To the Editor.
—At the present time, the pathogenesis and histologic characteristics of white ring of the cornea1 have not been clearly defined. The genesis of the lesion has been attributed to metabolic aberrations in the cornea, to trauma, and has even considered to be congenital. The composition of the lesion is equally unclear. Fat has apparently been identified,2,3 and the suggestion has also been made that the lesion is a calcific deposit.4-7We had the opportunity to observe and excise a clinically typical white ring of the cornea. With special handling of the tissue, the lesion was examined histochemically in serial section for the presence of lipid, calcium, PAS-positive material, and iron. The histopathologic characteristics of the lesion were also examined.These studies reveal that the white ring of the cornea stained strongly positive for iron but was negative for lipid and calcium. This finding is
Nevins RC, Davis WH, Elliott JH. COATS' WHITE RING OF THE CORNEA—UNSETTLED METAL FETTLE. Arch Ophthalmol. 1968;80(1):145-146. doi:10.1001/archopht.1968.00980050147026