With respect to the article by Agarwal et al, I would like to mention the following points:
The authors should have mentioned the source of itraconazole powder, because the crude drug is difficult to procure, and it is soluble in DMSO, not in any components of artificial tears. As they dissolved 100 mg drug in 100 ml solvent the concentration will be 0.1%, not 1%. They can not compare efficacy of 1% itraconazole with 0.3% fluconazole (usual formula) or 5% natamycin.
It is unclear whether the therapy was evaluated only clinically or microbiologically. In some cases of deep stromal necrosis, there may be residual opacity despite fungal clearance, because the healing phase of avascular cornea differs from that of inflammation elsewhere. Probably for that reason all 12 treatment non-responders were in the group of deep corneal ulcers. All 4 Fusarium isolates were itraconazole resistant but except for panophthalmitis all responded with natamycin. So the comparative efficacy of drugs ideally should be expressed in respect to a particular organism. Ten patients in this series were only clinically suspected keratomycosis without cultural confirmation. If these were distributed to either the superficial or deep ulcer group, therapeutic evaluation would be incorrect. Surprisingly in this series, only microscopy positive or only culture positive case were absent, and from none of the cases was bacteria isolated. The study should have included controls because repeated scraping can also have some therapeutic effect.
In all respects the 80% success rate of oral itraconazole therapy in 40 Aspergillus keratomycosis cases reported about 12 years back was more meaningful than the 77% success rate of the present study with 44 confirmed cases caused by several genera of fungi and treated by two different therapeutic approaches. The authors mentioned the need of a spore inhibition study. While this is justified, they have missed one such recent publication.
Source of Support:
Conflict of Interest:
1. Agarwal PK, Roy P, Das A, Banerjee A, Maity PK, Banerjee AR. Efficacy of topical and systemic itraconazole as a broad-spectrum antifungal agent in mycotic corneal ulcer. A preliminary study Indian J Ophthalmol. 2001;49:173–76
2. O'Day DM, Head WS, Robinson RD. Corneal penetration of topical amphotoricin B and natamycin Curr Eye Res. 1986;5:877–82
3. Thomas PA, Abraham DJ, Kalavathy CM, Rajasekaran J. Oral itraconazole therapy for mycotic keratitis Mycoses. 1988;31:271–79
4. Maiti PK, Bandyopadhyay S, Samajpati N. Evaluation of the use of antifungals in mycotic keratitis by in-vitro efficacy study of natamycin, fluconazole and itraconazole J Mycopathol Res. 2000;38:109–12