Pre-Descemet corneal dystrophy: case report and considerations on the current classification

Pre-Descemet corneal dystrophy (PDCD) has been classically described as a bilateral corneal disorder consisting of thin, opaque lipoprotein deposits at the posterior stroma, immediately anterior to the Descemet's membrane. Due to being asymptomatic, the condition is usually detected by chance and may go undiagnosed in an unknown percentage of the population. Except for a few specific syndromic associations or when a hereditary predisposition can be traced back in the family tree, PDCD can occur sporadically and independently of other systemic or ocular diseases. Since the description of PDCD a century ago to the present days, several reports using microphotography and high-definition corneal imaging have revealed that the histological changes observed in the affected corneas may not be exclusive to the pre-Descemet stroma. Moreover, histochemical evidence has shown that the intracellular inclusions corresponding to the corneal opacities are consistent with a degenerative process, rather than a dystrophic alteration. As new clinical and propaedeutical findings lead to a better understanding of the pathophysiology of PDCD, a split in its classification has been suggested in the latest publications. We present an isolated case with a typical biomicroscopic appearance of PDCD yet with corneal depositions at different levels of the stroma demonstrated by multimodal corneal imaging.