Fungal Keratitis Incidence Increases During Busy Agricultural Seasons

Fungal keratitis (FK) incidence increases during busy agricultural seasons, and prolonging treatment can yield unfavorable patient outcomes, according to research published in the American Journal of Ophthalmology.

Researchers included 251 patients diagnosed with FK at a university hospital in the retrospective, objective case series. Participants underwent anterior segment photography, in vivo confocal microscopy, corneal scraping, anterior segment-optical coherence tomography (AS-OCT), and bacterial and fungal culture examinations. The primary objective was to determine the epidemiological features, laboratory findings, and treatment outcomes of patients with FK.

Overall, 186 patients (74.1%; men, 66.7%; mean age, 58.2±9.5 years) developed FK during the busy agricultural season. Plant-related trauma (80.1%), particularly from maize leaves, was the main FK risk factor. A total of 14 patients did not have any known predisposing risk factors. Just over half of patients who presented during the busy farming period had positive fungal culture, which was most often Fusarium.

Researchers performed in vivo confocal microscopy (IVCM) and corneal scrapings when fungal cultures were negative. IVCM had a 94.6% positivity rate and 80.6% of corneal scraping samples were positive.

Most patients improved following topical drug treatment (68.8%) while the remaining participants underwent surgery due to deep or wide lesions. A total of 2 patients underwent corneal transplantation.

Visual acuity improved in 38.7% of patients after treatment. The necessity of surgical intervention was associated with a longer disease duration, deeper hyphae or spores, and wider infiltrate width ([IW]; P <.001 for all). 

Hypopyon depth (r =.423; P =.016), hyphae or spore depth (r =.423; P =.049), and IW (r=.220; P =.003) were associated with a longer time to presentation. Corneal thickness and IW in the infiltration area were linked with the depth of hyphae or spores (r=.163 and r=.480, respectively).

Researchers highlight the importance of utilizing eye protection while working in an agricultural setting and and state “[u]nderstanding regional epidemiological characteristics, risk factors, and pathogens is important for the prevention and appropriate management of [fungal keratitis].”

Study limitations include a retrospective nature and lack of a standardized data recording process.