Microsporidial Keratitis

Infectious keratitis: A review

“…They have been reclassified as fungi. The intracellular spore is the infectious form of the organism 113,114 . The infection can be transmitted via faeco‐oral, contaminated water or food for intestinal microsporidosis; however, the source for ocular infections is unknown 33,114 .…”

“…This organism can be identified as bright turquoise to white intracellular oval bodies clustered in groups against a dark background in 0.1% calcofluor white or 10% potassium hydroxide (KOH) stains 33,113,114 . Bright purple, ovoid, refractile spores similar to Gram‐positive organisms can be seen in Gram stains.…”

“…Other tests such as PCR and transmission electron microscopy (TEM) can be used to identify the species 33 . TEM is the gold standard for diagnosis of microsporidial spores but it is not easily accessible to most laboratories and further tests are needed to determine the species 114 . Pan microsporidian 16S rRNA has been used to identify the microsporidial species with a sensitivity of 83% and specificity of 98% 114 .…”

“…TEM is the gold standard for diagnosis of microsporidial spores but it is not easily accessible to most laboratories and further tests are needed to determine the species 114 . Pan microsporidian 16S rRNA has been used to identify the microsporidial species with a sensitivity of 83% and specificity of 98% 114 . A microsporidial infection should be considered as a differential diagnosis in culture‐negative stromal keratitis not responding to standard antimicrobial therapy 33,114 …”

“…Therapeutic penetrating keratoplasty may be needed in a non‐responding infection to medical therapy and for definitive therapy 33 . Microsporidia stromal keratitis has poor clinical outcomes and surgery is needed in most of the cases 33,113,114 …”