Plasma citrate levels as a potential biomarker for glaucoma

Area of Science:

• Biochemistry
• Ophthalmology
• Biomarker Discovery

Background:

• Glaucoma is a leading cause of irreversible blindness worldwide.
• Identifying reliable biomarkers for early glaucoma detection is crucial for timely intervention.
• Plasma citrate's role in glaucoma pathophysiology remains largely unexplored.

Purpose of the Study:

• To investigate the potential of plasma citrate as a diagnostic biomarker in patients with glaucoma.
• To compare plasma and urine citrate levels between glaucoma patients and healthy controls.

Main Methods:

• A case-control study involving 21 Caucasian glaucoma patients and 21 matched controls.
• Analysis of plasma and urine citrate and creatinine using ion chromatography.
• Statistical comparison of metabolite concentrations and fractional excretion rates.

Main Results:

• Significantly lower mean plasma citrate concentrations were observed in glaucoma patients (104.8±23.2 μmol/L) versus controls (128.2±31.1 μmol/L; P=0.01).
• Urine citrate levels showed a non-significant trend towards lower concentrations in glaucoma patients.
• Plasma and urine creatinine levels, as well as fractional citrate excretion, did not differ significantly between groups.

Conclusions:

• Plasma citrate levels are significantly decreased in Caucasian patients with glaucoma.
• Plasma citrate shows potential as a novel biomarker for glaucoma detection, with a sensitivity of 66.7% and specificity of 71.4% at a cut-off of 110 μmol/L.
• The cause of hypocitrataemia in glaucoma patients with normal kidney function requires further investigation.