BETA-D-GLUCAN TESTING IN PATIENTS WITH FUNGAL ENDOPHTHALMITIS

Purpose: To review the literature on beta-D-glucan (BDG) testing in fungal endophthalmitis. Methods: Review of primary literature using PubMed through April 2017 and presentation of an illustrative case report. A total of 231 articles were identified and 43 were ultimately chosen for review based on relevance and presence of ophthalmologic examination and objective data. Results: Beta-D-glucan is a major component of fungal cell walls. It is quantified using a calorimetry-based Fungitell assay based on modification of the limulus amebocyte lysate. Serum BDG levels are commonly used clinically in conjunction with other tests for early surveillance and diagnosis of invasive fungal infections. In the ophthalmic literature, elevated levels of BDG have been detected in vitreous fluid of patients undergoing vitrectomy for fungal endophthalmitis, tear fluid of patients with mycotic keratitis, and serum of a patient with bilateral endogenous subretinal abscesses. Elevated serum BDG levels appear to be highly associated with fungal endophthalmitis. Potential uses and considerations with regards to test limitations are discussed. Conclusion: Beta-D-glucan testing may be used as an adjunct to support a diagnosis, initiate pharmacologic therapy or surgical intervention, and optimize overall clinical management in patients diagnosed with or under clinical suspicion for invasive fungal infections, including endophthalmitis. Additional clinical studies are necessary to fully characterize the utility of BDG testing in patients with fungal endophthalmitis.