A comparative clinicopathologic study of endogenous mycotic endophthalmitis: variations in clinical and histopathologic changes in candidiasis compared to aspergillosis.

PURPOSE: Endophthalmitis caused by endogenous Candida and Aspergillus species has emerged as a visually threatening complication in patients with immune deficiency of various causes. Twenty-five patients who underwent enucleation, 13 with endogenous Aspergillus endophthalmitis and 12 with endogenous Candida intraocular infections, were evaluated. Both clinical features and intraocular spread of the fungi were studied to determine which clinical and/or histopathologic features could help distinguish aspergillosis from Candida infections.

METHODS: Clinical information was sought from each case to determine whether there was any underlying systemic condition and to delineate the characteristic clinical features seen at initial presentation. The results of vitreous and other tissue cultures for bacteria and fungi were evaluated. Patients with AIDS were excluded. The enucleated globes were processed for histopathologic analysis to detect location of the fungal elements, inflammatory response, and vascular invasion by the fungi.

RESULTS: With respect to the various predisposing systemic conditions, Candida species endophthalmitis was noted in patients with a history of gastrointestinal surgery, hyperalimentation, or diabetes mellitus, whereas aspergillosis was present in patients who had undergone organ transplantation or cardiac surgery. The vitreous was the primary focus of infection for Candida, whereas subretinal or sub-retinal pigment epithelium infection was noted in eyes with aspergillosis. Retinal and choroidal vessel wall invasion by fungal elements was noted in cases of aspergillosis but not in cases with candidiasis. The high rate of cerebral and cardiac infection in patients with Aspergillus endophthalmitis was not seen in those with Candida infection.

CONCLUSIONS: The present study indicates that unlike Candida endophthalmitis, aspergillosis is seen in organ transplant or cardiac surgery patients, and its initial clinical presentation includes extensive areas of deep retinitis/choroiditis. Contrary to the findings in Candida endophthalmitis, vitreous biopsy may not yield positive results in aspergillosis. Aspergillus endophthalmitis is usually associated with a high rate of mortality caused by cerebral and cardiac complications.