Atypical Fungal Keratitis Difficulty Of Diagnosis

Disclosure of Interest: None Declared

Infectious keratitis is a significant cause of corneal blindness worldwide.

Although less prevalence exists in the developed world, cases of fungal keratitis for almost half of all keratitis are occurring in the developing countries.

There are various challenges to the treating ophthalmologist, such as delayed presentation, long waiting time for culture positivity, limited availability effective antifungal drugs, prolonged duration for response to therapy, a highly variable spectrum of anti-fungal drug sensitivity and a high recurrence rate following keratoplasty

We received a 70 years old woman in the ophthalmological emergency department. The patient consults for an acute visual acuity decline appearing since 1 month, with a history of antecedent ocular  trauma and previous use of corticosteroids

On clinical examination, we had found reduced vision in the right eye: light perception, limited extraocular motion, with eyelid edema, meibomian gland dysfunction, severe inflammation, BUT<5seconds and Schirmer test<10mm as the severe eye dryness. In addition of conjunctival hyperemia and circumciliary congestion. On the cornea there was a deep purulent, circumscribed 7mm infiltrate, with a central thinning and hypopyon. Corneal thinning with iris prolapse and purulent discharge. corneal sensitivity was abolished.

The positivity of fungal culture for hypopyon was associated with duration of symptoms and lesion size. Corneal scrapings for microscopic evaluation and culture preparation, as the standard of care for establishing the diagnosis of fungal keratitis : culture-proven filamentous fungal keratitis.

The advent of rapid diagnostic tools, molecular methods, in vitro anti-fungal drug sensitivity testing, alternatives to natamycin, targeted drug delivery and most importantly the results of large randomized controlled trials have significantly improved our understanding and approach towards the diagnosis and management of cases with fungal keratitis.

Regarding the diversity of fungal aetiology and the emergence of drug resistance in some genera and species, proper identification using molecular methods and antifungal susceptibility testing could provide useful data. Furthermore, as the better efficacy of combination therapy in comparison to monotherapy is reported, in vitro determination of interactions between various drugs seem informative. This review aims to provide a general and updated view on the aetiology, risk factors, epidemiology, clinical and laboratory diagnosis, and management of fungal keratitis.