Is it fungal? No, it is not. A case of Pythium keratitis from Sri Lanka

Infectious agents are the commonest cause of corneal ulcers. Pythium insidiosum is a fungus-like aquatic oomycete capable of rarely causing human infections. Keratitis caused by Pythium insidiosum is associated with high ocular morbidity.
A 13-year-old boy from rural Sri Lanka presented with pain and tearing in the left eye for several days. While there was no history of trauma, he had bathed in a lake. A central corneal ulcer with satellite lesions was found on examination. The ulcer was non-responsive to topical and systemic antimicrobial therapy, and he underwent penetrating keratoplasty. However, the infection recurred and a second penetrating keratoplasty was performed a week later. Fungal studies indicated that both his corneal buttons were positive for Pythium species. Continued aggressive antimicrobial therapy resulted in a quiet, vascularised eye with retained perception of light vision.
Pythium keratitis requires prompt and adequate surgical and medical treatment. Clinicians’ awareness is important to diagnose this entity early.