Infectious keratitis in children
Paediatric microbial keratitis requires special diagnostic considerations
Infectious keratitis in children brings special challenges in diagnosis, and often require aggressive treatment to resolve, according to Vishal Jhanji MD, FRCS, FRCOphth, University of Pittsburgh School of Medicine Pittsburgh, USA.
“We face some real problems while managing infectious keratitis. Some of these include an uncooperative child, possible late presentation, lack of information prior to presentation, lack of information about previous treatments and use of traditional medicines in some parts of the world. And if you cross all these hurdles, you still have to deal with amblyopia in the recovery period,” Dr Jhanji told the 2020 WSPOS Virtual Meeting.
The main causes of infectious keratitis include contact lens use, inflammatory causes and ocular trauma, he noted.
Incomplete immunisation profile appears to contribute to its prevalence in the developing world. However, in developed countries where myopia has a high prevalence, the use of orthokeratology may be an additional risk factor. In a series of patients at tertiary care centre in Hong Kong, patients undergoing orthokeratology accounted for around 25% of microbial keratitis cases and 33% of contact lens-related keratitis cases.
SIGNS AND SYMPTOMS
The main signs and symptoms of keratitis include redness, pain, photophobia, conjunctival discharge and blurred vision. When examining the cornea, it is important to look at the location and size of the corneal infiltrate and epithelial defect, the degree of stromal oedema, corneal vascularisation and signs of corneal thinning and perforation. In addition, one should be careful not to overlook the presence of foreign bodies in the eye, Dr Jhanji advised.
He noted that corneal scrapings are more challenging in children, and general anaesthesia may therefore be required, especially in patients younger than five years. Cultures can also be obtained from contact lens cases and contact lens solutions. Bacterial isolates are more common than fungi and, unlike adult keratitis, can include coagulase negative staphylococci. Cultures for Acanthamoeba should be performed if indicated by clinical appearance or history.
Treatment of bacterial infections has to be aggressive, with frequent administration of antimicrobial agents. Fortified antibiotics are commonly used, although milder cases will often respond to topical moxifoxacin. Vancomycin eyedrops should only be used when absolutely necessary, due to their surface toxicity.
The spectrum of medications for fungal keratitis include topical natamycin (5%), fluconazole (0.5%) and amphotericin B (0.25%). Newer drugs with high corneal permeability such as voriconazole 1% eye drops can be used. Oral antifungals such as voricanazole are another option but baseline liver function testing is imperative, Dr Jhanji said.
Vishal Jhanji: email@example.com