Use of soft contact lenses for the study of external ocular microbiology

In the diagnosis of corneal ulcers, bacterial cultures from scrapings, investigations on viral and fungal growth, as well as staining of smears from the lesion often lead to the correct diagnosis. We report four cases of corneal ulcer where all the methods mentioned failed to reveal the causative microorganism. After the patients had received various medical treatments without any clinical improvement, soft therapeutic contact lenses were fitted, worn overnight, and removed the next morning with sterile forceps. The contact lenses were cultured in blood and Mac Leod agars. Growth of various bacteria was then detected. The infection subsided after the antibiotic treatment was changed according to the bacterial resistance. We conclude that, in selected cases, soft contact lenses may be used for microbiological studies.