The effect of fluorescein on the accuracy of blood glucose determination by glucose meters

Purpose: To investigate whether intravenous fluorescein significantly affec ted the accuracy of a glucose meter. il Methods: Thirty-four consecutive patients undergoing fluorescein angiograph y were recruited, Venous blood was removed immediately before and 1 hour af ter injection of 5 mis of 20% Sodium Fluorescein solution (1 mg), Whole blo od glucose was measured with a glucose meter and plasma glucose levels were measured by the Department of Biochemistry for both samples. The results w ere analysed using Wilcoxon matched pairs test. Results: Mean glucose results before fluorescein injection were 7.4 mmol/l (SD 4.5) with the glucose meter and 8.1 mmol/l (SD 5.0) biochemically (p=0. 02), The pest dose levels were 7.2 mmol/l (SD 4.7) and 8.5 mmol/l (SD 4.8), respectively (p=0.001), The difference between the mean results of the two tests was 0.7 mmol/l before fluorescein and 1.3 mmol/l after fluorescein ( p=0.001) Conclusion: Intravenous fluorescein appears to influence minimally the diff erence between glucose levels measured in the laboratory and by glucose met er. The degree of difference, whilst achieving statistical significance, sh ould not affect insulin dosage clinically.