Discriminat Analysis of Biochemical Parameters in Age Related Macular Degeneration and Diabetic Macular Oedema Patients

Abstract

Purpose: : The biochemical and molecular mechanisms responsible for the pathogenesis of Diabetic macular edema (DME) and age-related macular degeneration (ARMD) are not yet established. Hence, in the present work we apply discriminant statistical analysis associating biochemical parameters with funduscopic characteristics from ARMD-DME patients.

Methods: : After a complete eye examination, peripheral whole blood was obtained from patients with ARMD-DME (n=23), diabetic patients without diabetic retinopathy or DME (n=13) and age-matched non-diabetic, non-ARMD patients (n=12). Quantitative assays were performed for more than 22 different biochemical parameters measured by conventional clinical laboratory tests and flow cytometry. LRP1 was determined from monocytes of peripheral blood by flow cytometry using RD1-conjugated monoclonal antibody against human LRP1 alpha chain. At least 2,000 gated monocytes were acquired in each sample using the flow cytometer. All biochemical, cytometric and clinical parameters were analyzed using Lineal Discriminant Analysis (forward stepwise mode) and Kruskal Wallis (Statistica version7.0).

Results: : A discriminant analysis (forward stepwise) allowed us to select 7 biochemical parameters (out of 22 analyzed) as the most important for discerning ARMD-DME patients respect to control groups. The parameters found were: LRP1 together with HDL-cholesterol; Red Cell Distribution Width (RDW); Haematocrit, Medium Corpuscular Volume (MCV); Lymphocytes; Platelets; and Cholesterol which were statistically different between ARMD-DME patients and control groups (p≤0.05). These 7 parameters allow us to differentiate these two groups with a 95% certainty.

Conclusions: : These results indicate that these 7 biochemical parameters are key markers that highly discriminate ARMD-DME patients from any other retinal disease and could be common pathways involved in the pathogenesis of these macular pathologies.

Keywords: age-related macular degeneration • diabetes • flow cytometry