An 18-year-old male patient with a history of redness, pain, watering, foreign body sensation and diminution of vision in his right eye for the past month was referred to us. The patient had a prior history of trauma to the right eye with dust particles, subsequent to which he had put honey in the eye for symptomatic relief. The application of honey in the eye could be a source of keratitis. On presentation, the Snellen visual acuity was hand motion close to the face with accurate projection of rays in the right eye and 6/6 in the left eye. Slit-lamp examination revealed a near total epithelial defect with corneal infiltrates of 8x8 mm extending up to 1/2 of corneal thickness with circumciliary congestion and lid edema (Figure 1 (Fig. 1)). Corneal scrapings were taken for smear and culture, and Staphylococcus aureus was isolated in bacterial culture, which was sensitive to moxifloxacin, gatifloxacin, cefazolin, and vancomycin. Confocal microscopy was performed, which revealed the presence of fungal hyphae (Figure 2 (Fig. 2)). Posterior segment examination on ultrasonography did not reveal any evidence of presence of vitreous exudates or retinal detachment. Treatment was started with topical voriconazole 1% (prepared my mixing 20 mL ringer lactate to 200 mg voriconazole lyophilised powder), natamycin 5% (commercially prepared eye drops), vancomycin 5% (500 mg of vancomycin powder was reconstituted with 2 mL sterile water and then added to 8 mL of artificial tears), administered every hour with homatropine hydrobromide 2% QID and oral voriconazole at a dosage of 200 mg twice daily. After 3 days, the lesion had not progressed, but there was no change in corneal infiltration or epithelial defect, and the patient had worsened symptomatically. The culture report was negative for fungus and Acanthamoeba. At one week, there was a further increase in symptoms and no reduction in infiltrates. The patient was subsequently switched from concentrated vancomycin to topical 0.5% moxifloxacin. The epithelial defect remained unchanged. Meanwhile, a corneal scrape GeneXpert sample to rule out atypical mycobacterium also turned out to be negative. GeneXpert is a cartridge-based nucleic acid amplification test (NAAT) for rapid diagnosis of tuberculosis and atypical mycobacteria. In view of the poor response with clinical worsening on day 14 of starting the treatment, we decided to replace topical natamycin with topical caspofungin acetate 0.5%, applied every hour.
To prepare the eyedrops, 1 vial of 50 mg of caspofungin acetate was diluted in 10.5 mL of sterile normal saline; all eyedrops were freshly prepared weekly, kept at 4 C, and protected from light. Three days later, clinical improvement was observed. Following the commencement of the treatment, healing of the corneal epithelium and resolution of the corneal infiltrate were observed from the periphery towards the centre with evidence of vascularisation, and the patient showed commendable clinical response (Figure 3 (Fig. 3)). At 6 weeks of follow-up, the ulcer had healed completely. Although the patient initially had limbus to limbus corneal infiltrates, the scarring was less dense and involved superficial cornea with relative peripheral corneal sparing (Figure 4 (Fig. 4)). The patient attained an uncorrected visual acuity of 6/36 in the right eye, which improved to 6/12 with a trial of rigid gas permeable (RGP) contact lens.