A key challenge of pediatric microbial keratitis is that international study results have varied widely — from trauma being the chief predisposing element in economically developing areas, to contact lenses being the most important aspect in regions of higher income — thus overall data is scarce. Other challenges include greater inflammation than in adults, and the difficult task to keep a child’s topical medication dosage steady.

An analysis published in Clinical Ophthalmology shows a majority of keratitis cases are avoidable. In that study, 62.7% of cases were considered secondary to preventable risk factors, the researchers report. Those factors, again, are identified as contact lens misuse and trauma. 

Investigators identified medical records for all patients with a diagnosis of nonviral microbial keratitis (n=602) at a single eye care facility from 2010 to 2020, of which 59 patients were 18 years of age or younger, and 3 displayed bilateral infection.


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Upon presentation, 49.2% were taking antibiotics. Corneal scraping was performed for 66.1% of the pediatric patients, and all positive cultures demonstrated a bacterial cause. Cultures from corneal or lens samples revealed gram-negative isolates for 47.1%, predominantly Pseudomonas aeruginosa. Gram-positive isolates were identified in 23.5%, including Staphylococcus aureus, S. capitis, and Kocuria rosea. Also, mixed growth was found in 29.4% of cultures.

Specific predisposing elements could be identified for 89.8% of children. Of these, contact lens wear was a top influence in 35.6%, trauma for 27.1%, ocular disorders affected 11.9%, systemic disease for 10.2%, and prior ocular surgery in 5.1%. The remaining 10.2% were unidentified. By age, a majority of children older than 10 years were impacted by contact lens wear, and leading causes for those younger than 7 years were equally split between trauma, ocular disorder, and systemic disease. Trauma had a greater impact on kids between the ages of 7 and 10 years. 

Treatment comprised fortified antibiotics for 74.6% — most-prescribed were cefazolin and ceftazidime, as well as vancomycin and ceftazidime. Fluoroquinolones were ordered for 20.3% of patients, with 2 cases adding fusidic acid; and 3 individuals remained on antibiotics they were taking previously. Steroids were prescribed for 55.9% of children, starting 2.1±6.7 months from their initial visit.

Mean follow-up time was 23.4 months, ranging from 0.10 to 114.1 months. Although 91.5% responded to treatment, 71.2% developed a corneal scar. Visual acuity (VA) was documented for 78.0% of baseline exams and 74.6% of final visits, with initial mean corrected distance VA (CDVA) of 20/214 improving to 20/40, an increase of 7 lines (P <.001). However, 32.2% experienced a poor outcome, such as final VA less than 20/30, 1 or more Snellen lines lost, or other complications. Also, 11.9% needed additional procedures such as deep lamellar keratoplasty, photorefractive or phototherapeutic keratectomy, or penetrating keratoplasty

The retrospective design was a study limitation, as well as a possible underestimation of illness-related predisposing factors due to fewer children with systemic or serious diseases typically visiting a tertiary eye center. “Good evaluation and management of suspected cases should not be compromised by the difficulty in evaluating and obtaining adequate scraping samples,” the investigation suggests.

Reference

Alwohaibi NN, Bamashmoos M, Al Somali A. Pediatric non-viral microbial keratitis: predisposing factors, microbiological profile, treatment modalities, and visual outcome. Clin Ophthalmol. 2022;16(3):775-783. doi:10.2147/OPTH.S323408