الفهرس 
Pathogenic Fungi and Pathogenesis of Fungal KeratitisOnly 14 pages are availabe for public view
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Abstract
Fungi are opportunistic organisms that are recognized more frequently as ocular pathogens in rural tropical countries than in the developed world.
For clinical purposes, fungi can be classified on morphological basis into filamentous, yeast and dimorphic forms.
Major risk factors for fungal keratitis include : ocular trauma ( mainly by vegetable matter), contact lens wear, topical steroids use and history of surgical procedures including mainly photorefractive keratectomy and LASIK.
Fungal keratitis is indeed a diagnostic and therapeutic challenge to ophthalmologists. That is why proper diagnosis and treatment should be focused on for improvement of diagnostic and therapeutic modalities, especially that it can cause serious complications that may be a leading cause of blindness.
Diagnosis of fungal keratitis starts with clinical suspicion, based on its specific characters, including satellite lesions, feathery margins, brown pigmentation, endothelial plaque and peaked hypopyon. Clinical suspicion should be followed by corneal scrapings for culture (mainly on sabouraud dextrose agar and brain heart infusion broth), and then staining with various stains including gram, giemsa, KOH 10% or calcofluor white using fluoresent microscopy, and interpretation of film results for identification of various species of fungi.
Antifungal sensitivity is a modality that can help to reach the specific antifungal agent to which the fungi are sensitive, and can aid for better prognosis of fungal keratitis.
Antifungal agents can be mainly classified into three main categories: polyenes ( as amphotericin B and natamycin), azoles (imidazoles as miconazole and triazoles as fluconazole) and fluorinated pyrimidines ( as flucytosine).
Treatment of patients with fungal keratitis needs regular and close follow up for improvement or development of any complications and their management accordingly.
We included 14 eyes of 14 patients in the study, where corneal scrapings were taken from cases of suspected fungal keratitis clinically, then cultured, and when fungal growth occurred, Giemsa stained films were examined and antifungal sensitivity to both fluconazole and amphotericin B was performed.
We concluded that in this sample of patients, filamentous fungi were more common and sensitivity to fluconazole was more common.
Our study showed the role of smears, cultures and sensitivity in diagnosis and treatment of fungal keratitis.