When comparing the infectious contact lens-related corneal ulcer (CLRU) and non-CLRU cases at Saint Louis University, researchers from the eye institute found CLRUs were disproportionately associated with Pseudomonas species and non-CLRU with Staphylococcal species.

This retrospective review included 677 cases of corneal ulcers, 46% of which were CLRUs, most commonly seen in younger patients and women.

The team discovered that many of the infections were vision-threatening, as defined by central/paracentral location (73% CLRU and 71% non-CLRU) and ulcer size (>2mm² in 36% CLRU and 51% non-CLRU). They note that the causative pathogens in cultured CLRUs were predominately Pseudomonas (44%), other gram-negative (6%), gram-positive (33%), fungal (13%) and Acanthamoeba (5%) species. On the other hand, cultured non-CLRUs were predominately gram-positive (64%), gram-negative (26%) and fungal (11%) species. They add that the combined oxacillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus isolates were 35% and 34%, respectively.

Despite the progressive increase in the number of corneal ulcers seen, the study notes that the annual trend for any one particular organism for either CLRU or non-CLRU cases did not change significantly.