Abstract
Purpose :
Fungal endophthalmitis is a devastating intraocular inflammatory disease that represents ~17-25% of infectious endophthalmitis in India, but microbiological investigations have often failed to detect the causative agent, resulting in a clinical dilemma. Galactomannan (GM) and 1,3 β-D-Glucan (BG), have been previously evaluated in the diagnosis of invasive fungal infections, however, its utility in intraocular infections is not known. The aim of the study was to assess the clinical utility of vitreous GM and BG levels in the diagnosis of fungal endophthalmitis.<gdiv></gdiv>
Methods :
Vitreous of 31 patients diagnosed clinically as fungal endophthalmitis between October 2018 and September 2020 and 11 patients diagnosed with non-infectious retinal disorders, as controls, were included in this study. Human GM and BG levels were determined by colorimetric assay kits (MyBioSource) and the receiver operating characteristic curves (ROC) were determined.<gdiv></gdiv>
Results :
Of the 42 patients included in the infectious group, 16 were culture-positive and included Aspergillus spp. (44%), Candida spp. (31%), and other fungi (4/16; 25%). While, no significant association were found between GM and BG levels and visual outcome, significantly higher levels of vitreous GM (67.51±22.08pg/ml; p=0.009) and BG (1.53±0.30pg/ml; p=0.0002) were found in the culture-positive group compared to the control group. Additionally, both GM and BG levels were significantly higher in Aspergillus spp. compared to Candida spp. (p-value <0.05). The Area under the ROC curve (AUC) value for GM was 81% with a sensitivity of 88% and a specificity of 73% for a cutoff value of 51.36pg/ml. Further, the AUC value for BG was 93% with sensitivity and specificity of 94% and 82% with the cutoff value being 1.19pg/ml. Using that criteria, diagnosis of fungal infection was achieved in 12/15 (80%) culture-negative infectious samples by GM assay and in 15/15 (100%) by 1, 3 β-D-Glucan assays.<gdiv></gdiv>
Conclusions :
Our study demonstrates the clinical utility of GM and BG as useful adjunctive biomarkers for the early diagnosis of fungal infections in patients with culture-negative endophthalmitis. A combination of both BG and GM assays would be the best approach, facilitating better predictive accuracy in vitreous fluids and may have a role in monitoring response to therapy.<gdiv></gdiv>
This is a 2021 ARVO Annual Meeting abstract.