الفهرس 
OCULAR DEFENSE MECHANISMSOnly 14 pages are availabe for public view
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Abstract
Infections of the eye give rise to severe ocular morbidity
and blindness include keratitis, orbital cellulites,
endophthalmitis . Corneal blindness, in developing countries is
predominantly associated with infections. In India, nearly 30-
35% of all culture positive infectious keratitis are caused fungi.
Laboratory diagnosis mainly depends upon proper collection
and transport of clinical specimens. In fungal keratitis, corneal
scraping is the ideal sample, but occasionally corneal biopsy or
anterior chamber aspirate may also be needed.
Corneal scraping is usually by Kimura spatula, under a slit
lamp examination, after anaesthetizing the cornea with topical
anaesthetic like 0.4% proparcaine. Corneal biopsy is done by a
minor trephining and recently by Femtosecond laser–assisted
corneal biopsy .
In case of endophthalmitis vitreous fluid is collected by
pars plana vitrectomy onto sterile tuberculin syringe, the needle
is then fixed to a sterile rubber bung after expelling air from the
syringe. The collected sample is immediately transported to the
laboratory. wound aspirate/ swabs are the ideal specimens for
orbital cellulites, respectively. These samples are cultured onto
SDA slants following standard procedures. The main draw back
of culture is its long incubation time (5 to 14 days), though it is
indispensable from the view point of the specificity. Direct
Summary
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examination (KOH wet mount, Gram’s, Giemsa or calcofluor
fluorescent staining methods) of the specimen, however, is
quick and immensely helpful for ophthalmologist. The newer
rapid methods, such as molecular techniques are also available
and the management of patients can be according to the results
obtained. With the advent of novel antifungal agents such as
newer azoles and cell wall acting antifungals like echinocandins,
the clinician has the wider option of selecting the therapeutic
modality. In the event of the increasing reports of in vitro drug
resistance to much frequently used azoles, polyenes and 5-
fluorocytosines, clinical applicability of the newer antifungal
agents seems to be quite promising