A pinguecula is a yellowish-white fluorescent mass situated over the sclera on one or both sides of the cornea. Its pathogenesis is far from clear, but it appears to be determined genetically and to assume tumorous proportions only in middle life or later.
Histologically pingueculas vary from masses of amorphous hyaline substance to masses of coiled and fragmented tissue that simulate pathologic elastic tissue elsewhere (e.g., pseudoxanthoma elasticum1), but they are unlike any tissue occurring normally about the eye. This amorphous and fragmented tissue stains regularly with orcein and resorcinol fuchsin dyes or by Verhoeff's method, whence it is called (degenerated) elastic tissue. It does not stain with Sudan and is variably colored by basic and acidic stains.
In 1949 Balo and Banga2 described a nonproteolytic enzyme derived from pancreas which had the specific property of solubilizing elastic fibers. This enzyme, which is active on fresh or
COGAN DG, KUWABARA T, HOWARD J. The Nonelastic Nature of Pingueculas. AMA Arch Ophthalmol. 1959;61(3):388-389. doi:10.1001/archopht.1959.00940090390008