Amyloidosis of corneal stroma in patients with trachoma. A clinicopathologic study of 62 cases.

Sixty-two cases of corneal amyloidosis were studied. The median age of the 48 men and 14 women was 66 years. The patients had bilateral, diffuse corneal opacity extending to the limbus and severe visual impairment. The corneal condition was not familial. Advanced stages of trachoma were present in all individuals. Climatic droplet keratopathy (CDK) was also observed clinically in 19 patients. Histopathologically, the Congo red-positive, birefringent and dichroic amyloid deposits in the stroma were similar to that of lattice corneal dystrophy. Bowman's membrane was mostly absent, and peculiar microcystoid degeneration of the stroma was noted. Electron microscopic studies not only confirmed the diagnosis of amyloid but also showed a more diffuse amyloid pattern than did light microscopy. Trachoma is probably the cause of this corneal degeneration with secondary amyloidosis. The environmental conditions associated with CDK may be contributing factors in some cases.