Fungal Keratitis Caused by Exserohilum, An Emerging Pathogen

To determine the epidemiology, risk factors, clinical features, and prognosis of fungal keratitis caused by Exserohilum.

All culture-proven cases of keratomycosis caused by Exserohilum presented from January 2012 to December 2014 were retrospectively analyzed using a computerized database.

Among 1542 cases of keratomycosis, 47 (3%) were due to Exserohilum. The mean age of presentation was 50.4 years. Males (n = 32; 68%) were more commonly affected than females (n = 15; 32%). A history of trauma was present in most of the cases (n = 38; 80.9%). The mean time of the first visit to the hospital was 6.2 days after onset of symptoms. Most of the patients (n = 24; 72.3%) had central or paracentral ulcers. The infiltrate was confined to the superficial one-third of the stroma in 39 patients (83%). Most of the patients (89.4%) responded well to topical treatment (natamycin 5% for ulcers <5 mm; voriconazole 1% was added for ulcers >5 mm or with hypopyon); 4 patients (8.5%) required therapeutic penetrating keratoplasty and 1 patient (2.1%) progressed to endophthalmitis, requiring evisceration. The mean best-corrected visual acuity in the medically treated patients improved from 0.89 (logMAR) at presentation to 0.77 at the completion of treatment (P = 0.015).

This study signifies the importance of this new emerging pathogen that was generally regarded as rare in the past. The infection seems to be more prevalent than previously thought, especially in hot and humid areas. Vision is likely to improve if the infection is diagnosed and appropriate topical treatment is started early.