Microsporidial Endotheliitis Mimicking Graft Rejection After Deep Anterior Lamellar Keratoplasty

The purpose of this study was to report a case of microsporidial endotheliitis masquerading as graft rejection after deep anterior lamellar keratoplasty (DALK).

A 36-year-old man visited the clinic with complaints of blurred vision, redness, pain, watering, and whitish appearance of the black portion of his left eye. On evaluation, there was diffuse stromal edema with epithelial defect and hypopyon. Microbial keratitis resolved with macular grade scar. He underwent DALK. After 3 years, he presented with complaints of sudden diminution of vision in the same eye for 10 days. His unaided visual acuity was counting finger 1 meter. The clinical findings were circumcorneal congestion, diffuse graft edema, Descemet membrane folds, and diffuse keratic precipitates. A presumptive diagnosis of left eye graft rejection was made. Topical steroids were administered. There was significant improvement within a week. However, at 1 month, there was an increase in graft edema after the steroids were tapered. At this point, a diagnosis of endotheliitis of viral origin was made. He was then administered oral antivirals and steroids. There were 2 such waxing and waning episodes of graft edema before the graft failed. Patient underwent penetrating keratoplasty with cataract extraction with intraocular lens implantation.

The previous donor and host Descemet endothelium complex was sent for histopathology and polymerase chain reaction. Both histology and polymerase chain reaction were positive for microsporidia.

Microsporidial endotheliitis may present as graft rejection. There should be a suspicion of microsporidial infection in cases of features mimicking as endothelial rejection after DALK.