PURPOSE: The study of fungal invasion and pathogenicity in corneal tissue observed through the histopathological examination of specimens obtained through penetrating keratoplasty ('PKP') of samples obtained from an Eye Bank ('EB'), with the aim of applying findings in diagnosis and treatment of the condition METHODS: Retrospective non-comparative case studies on samples collected between January 2006 and June 2011 based on identification data comprised of scant historical information sent by surgeons and material obtained through PKP, consisting of 38 samples from 35 patients. Processing involved special stains for fungi in order to detect the presence thereof, with one to three colourations being performed in accordance with diagnostic difficulty in relation to each sample. RESULTS: Patients were predominantly male (20 compared to 15 females), and the most represented age group was 60+ years of age (1/3 of the patients). Mycotic keratitis was detected in 6.4% (n= 597) of cases referred to the EB and in 1.65% (n= 2310) of transplants using corneal material provided by the EB over the last five years. According to historical information provided by surgeons, 39.5% (n= 38) of cases were due to perforation of the cornea. A statistical table was prepared using transplant data. 11 specimens (n= 38) were due to an anterior corneal graft. Yeasts were present in 63% (n= 38), and 50% (n= 38) of corneal tissue had mild or non-existing inflammation. 13% (n= 38) had whole Descemet layers, while 45% (n= 38) presented fungi on the corneal surface. CONCLUSION: Corneal grasping and confocal microscopy may be performed successfully after treatment has been initiated, although in corneal ulcers samples should ideally be collected with a spatula for laboratory testing in vivo. The high prevalence of yeasts in the samples we looked at may be due to morphologic changes in corneal tissue of fungal origin. Intraocular penetration of the fungi is facilitated by changes to the Descemet layer, and assisted by the fungi's own properties. Therefore systemic treatment is justified from the outset.
Keratitis; Keratitis; Eye infections; fungal
