Successful treatment of fusarium keratitis after photo refractive keratectomy.

Dear Sir,

We read the article “Successful treatment of fusarium keratitis after photo refractive keratectomy” by Gan Maria Cavallini et al.,[1] with interest and would like to offer the following comments.

The authors have not mentioned what guided the initial treatment protocol. It is not clear what the result of the initial scraping was? In such a scenario, suspecting fungal keratitis, the dosing of amphotericin B at 4-h intervals seems too low. An hourly dosing would be more appropriate in terms of fungal keratitis.[2]

Amphotericin B is the drug of choice for yeasts and dematicae. It is known to have poor activity against filamentous fungi. In such a scenario, with the mycological examination still inconclusive, it seems more appropriate to add natamycin to the mix to cover all filamentous fungi. Thus, our drug regimen of choice in unknown fungal keratitis is combination of topical amphotericin B with topical natamycin 1 hourly in the initial stages.

The authors have noted an increase in the size and density of the lesion after 2 days. But no escalation of the therapy has been noted. An increasing size of infiltrate at 48 h indicates either inappropriate/inadequate therapy or presence of resistant organism. A review of the medication at this stage is warranted and should have been done.

After the first keratoplasty, the dose of amphotericin B has been unexplainably decreased to 4 times per day. In a scenario where even 4 hourly usage of the drug is not controlling the infection, reducing the frequency seems baffling.

The authors have, in the discussion, justified withholding voriconazole therapy on the basis of awaited culture results. This again is baffling, as normally one would start a second drug of choice when expected response is not given by the current therapy, rather than wait for laboratory results.