Tophus-like, conglomerated, crystalline calcification of the sclera.

The clinical history and the pathohistological findings of a peculiar form of multifocal scleral calcification in 3 globes of 2 patients are described. It consisted of globular drusen of rod-like crystals, fusing into large, tophus-like conglomerates. The crystals consisted of monoclinic and triclinic calcium pyrophosphate. The deposits can be interpreted therefore as scleral pseudogout. They were combined in places with a diffuse, idiopathic inner scleral calcification. The pathogenesis of these mineralizations is unclear. No signs of a dystrophic calcification were present. One patient, suffering from Alport's syndrome, had been normocalcemic for the last 16 years after renal transplantation, and no disturbed calcium metabolism was known in the second case.