Late-onset granular intra-amniotic infection following amniotic membrane transplantation

BACKGROUND: The amniotic membrane (AM) is used in ocular surface reconstruction and is effective at promoting epithelialization and preventing corneal perforation in cases of acute microbial keratitis. Here, we report a case of isolated AM infection after AM transplantation for a persistent epithelial defect following tectonic penetrating keratoplasty. CASE PRESENTATION: A 47-year-old man with poorly controlled type 2 diabetes mellitus presented to the emergency department with a referral for perforated microbial keratitis. After ophthalmic examination, corneal scraping was performed, and corneal gluing was attempted and failed. Hence, the patient underwent tectonic penetrating keratoplasty. After keratoplasty, the patient developed a persistent epithelial defect that required AM transplantation as an overlay. Thirty days post-AM transplant, the patient presented with signs and symptoms resembling granular microbial infection of the cornea. After two days, the granular findings began dislodging from the corneal surface and were sent for culture, sensitivity, and histopathological identification. Histological analysis of the granular material indicated it to be a small piece of AM stroma infiltrated with mixed-type inflammatory cells. Corneal scraping cultures indicated Streptococcus mitis and Streptococcus oralis. CONCLUSION: The infiltrate was localized to the basement membrane of the AM as, despite the anti-inflammatory effects of AM, it can also act as a barrier against polymorphonuclear leukocyte infiltration from the tear film and microbial invasion into the cornea.