Sir,

We report an interesting case of corneal ulcer due to combined fungal and acanthamoeba infection, which was diagnosed by in vivo confocal microscopy.

Case report

A 32-year-old male patient presented with a history of redness, pain photophobia, and blurred vision in the right eye of 1-week duration. He is an agriculturist by profession. There was no history of contact lens wear or trauma to the eye.

His best-corrected visual acuity was counting fingers close to face and 6/6 in the right and left eye. Slit-lamp examination of the right eye revealed a corneal ulcer involving the temporal cornea extending from 7 o'clock to 11 o'clock along with a hypopyon (Figure 1). The left eye was normal. In vivo confocal microscopy (Rostock cornea module with HRT II, Heidelberg Engineering, Heidelberg, Germany) revealed plenty of fungal filaments, a few acanthamoeba cysts and trophozites (Figure 2a and b). Corneal scraping for fungus revealed Fusarium species. Culture for bacteria and acanthamoeba were negative. He was started on hourly application of Natamycin 1%, propamidine, and polyhexamethylene biguanide (0.02%) eye drops. In vivo confocal microscopy was used to monitor the response of the treatment. Natamycin eye drops were tapered and eventually stopped after 40 days, whereas propamidine and polyhexamethylene biguanide were stopped after 3 months. At the third month follow-up, the ulcer has healed well with scarring and vascularisation. His best-corrected visual acuity in the right eye had improved to 6/9. Confocal microscopy showed plenty of dendritic cells at the area of the corneal ulcer. No fungal filaments, acanthamoeba cysts, or trophozoites were noted.

Figure 1
figure 1

Slit-lamp photograph of the right eye showing corneal ulcer in the temporal cornea with hypopyon at presentation (× 10).

Full size image
Figure 2
figure 2

(a) In vivo confocal microscopy showing plenty of linear fungal filaments (× 800). (b) In vivo confocal microscopy showing double-walled acanthamoeba cysts (× 800).

Full size image

Discussion

In vivo confocal microscopy using the principle of confocal microscopy, with an axial resolution of 5–10μ and lateral resolution of 1μ, enables us to understand the pathology at a cellular level.1, 2 The early detection of double-walled acanthamoeba cysts and trophozoites on confocal microscopy in this patient, with no growth on culture, completely alters our management and eventually a good prognosis.2 Follow-up of these corneal ulcers with confocal microscopy helps us understand the changes occurring at the cellular level and moderate our treatment accordingly. We feel this tool can be used in our day-to-day practice in the management of combined corneal infections.