Contributors: Theresa R. Kramer and Hans E. Grossniklaus
Pseudocrystalline keratopathy (infectious pseudocrystalline keratopathy) is a rare corneal infection characterized by progressive, crystalline-like, branched corneal infiltrates located in the anterior and caused by an infectious agent that is usually minimally virulent. The keratopathy usually occurs in eyes that have had previous accidental or surgical trauma. Infectious pseudocrystalline keratopathy is frequently caused by the growth of minimally virulent bacteria, such as Streptococcus viridans. Members of the Streptococcus genus (especially Streptococcus viridans) are the most common organisms, but other causative agents include Haemophilus aphrophilis and some fungi (Candida tropicalis, Alternaria). The epithelium is absent in the area of a superficial corneal infiltrate composed of solid masses of bacteria interspersed between the collagen lamellae. The use of topical corticosteroids on the eye dramatically dampens the effects of neutrophil-mediated inflammation and allow the organisms to proliferate relatively unimpeded in the virtual absence of inflammation.