Niranjan Nayak* and Gita Satapathy
Endophthalmitis is a severe vision threatening intra-ocular infection. Endophthalmitis of fungal origin is mostly endogenous but may also occur following intra-ocular surgery, corneal ulceration or trauma. Clinically these conditions are difficult to diagnose and are often missed, without proper microbiological investigations. Hence, laboratory diagnosis is very important for the initiation of appropriate antifungal therapy. Whereas, laboratory diagnosis of fungal endophthalmitis is based mainly on conventional microbiological methods, these techniques are not sensitive enough for any aetiological conclusion to be established. The main reasons for this low sensitivity is minimal number of organisms in the eye,the small sample size, a tendency of these organisms to be loculated and inappropriate transport and storage of the samples, if collected during an emergency surgery when the laboratory is closed. Results of studies in India as well as abroad,indicate a low incidence of fungal endophthalmitis varying between 3-8%.Amongst the cuture positive cases, Aspergillus flavus alone accounts for 36% of cases, followed by Aspergillus fumigatus in 20%,A niger in 10%,Fusarium in 21% and Alternaria in 13% cases.Candida and Aspergillus species, however, remain the predominant organisms isolated in endogenous endophthalmitis. Histoplasma capsulatum var.capsulatum and Coccidioides immitis are also reported to be the causative agents of metastatic endophthalmitis and should be considered in the clinical diagnoses of cases at places where these diseases are endemic as well as in patients who are immunosuppressed. In post-operative cases, Aspergillus species, Fusarium species, Alternaria species have been reported to be the common causative agents. Aspergillus, Alternaria ,Bipolaris, Acremonium, Fusarium species mostly account for post-traumatic cases. A recent retrospective analysis of the laboratory records of all clinically diagnosed endophthalmitis cases during the period from 2001-2010 at our tertiary care eye centre revealed that fungi alone accounted for 11% all infectious endophthalmitis cases and 5 % of the cases had mixed etiology . Our data were in agreement with the findings of others in the USA who documented an overall positivity of fungal isolation amongst all cases of infectious endophthalmitis to be somewhere between 11 to 16 percent. Sensitive technique such as PCR of intra-ocular fluid has not only helped the clinician in timely administering appropriate antifungal antibiotics,but has also improved on the rapid laboratory identification and speciation of the fungal pathogens.
Share this article