Microsporidia Stromal Keratitis presents more commonly in immune competent patients. Risk factors include contact lens wear, trauma or travel to Southeast Asian countries with exposure to contaminated water. Patients present unilateral progressive eye redness, vision loss and pain. This presentation is often misdiagnosed as herpes simplex virus, so a corneal scraping or biopsy should be performed to confirm the diagnosis [1-5].
Figure 1: Histological examination of the corneal biopsy reveals intrastromal infiltration of microsporidia.
Figure 2: Histological examination of the corneal biopsy reveals birefringent under polarized light.
Birefringence is a unique quality of the microsporidial polar tubules, which are used by the organism to inject infected sporoplasm into the host cell. The treatment is variable, but oral albendazole has been shown to be effective in recent studies.