Abstract
Purpose :
Endophthalmitis may cause severe vision loss due to damage to ocular tissues including the retina. The identification of molecular and metabolic factors involved in the disease pathogenesis are crucial for early clinical intervention. In the current study, we propose to identify tear based metabolite biomarkers for effective diagnosis and prognosis of early endophthalmitis infections.
Methods :
All patients suffering from endophthalmitis of any origin, i.e., post-operative, traumatic, or endogenous were included in the study which was approved by Institutional Ethics Committee. Untargeted metabolomics was performed to evaluate the metabolic responses in ocular fluids including vitreous humor, aqueous humor and tears (N=28) of bacterial endophthalmitis patients. MetaboAnalyst R package was used to perform multivariate data analysis and pathway enrichment of metabolites. Supervised partial least-squares discriminant analysis method was performed to identify clusters to locate metabolites across various grades of different sample types. VIP score was calculated as a coefficient for the selection of each variable.
Results :
The volcano plot showed the significantly altered m/z values (log fold change>2, p<0.05), with 467 m/z to be upregulated and 669 m/z to be downregulated. In tears, Myristoleolyl Carnitine showed significant increase in the levels from grade 3 to grade 5. In Grade 1 and 2 the levels were not significantly altered as compared to the controls which correlated with results from vitreous and aqueous humor. The metabolite 1-palmitoyl-sn-glycero-3-phosphocholine peak intensities showed increase from Grade 2-5 as compared to controls. L-Glutathione metabolite showed decreased levels in grade 4 and grade 5. L-Glutathione (AUC:0.946), Myristoleoyl Carnitine (AUC:0.601) and 1-palmitoyl-sn-glycerol-phosphocholine (AUC:0.731) were the three metabolites with best classification capacity in tears for bacterial endophthalmitis.
Conclusions :
Early diagnosis and proper treatment of endophthalmitis are keys to saving the eye and possibly the life of the patient. Our data identified a diagnostic tear metabolite marker Myristoleolyl Carnitine for bacterial endophthalmitis, which has potential to be used for rapid detection and decision of treatment strategy without using the conventional and time consuming diagnostic approaches.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.