Association between drusen and blood test results in a colony of 1,174 monkeys

Purpose To ascertain the association between fundus drusens and biological parameters in a colony of 1174 monkeys. Methods Presence or absence of drusens was determined through the assessment of fundus photos taken during 2011 – 2013 from 1,174 Macaca fascicularis at Tsukuba Primate Research Center. Biological data from these monkeys including blood test result, age, sex, and body weight were tested for an association between the presence of drusens by applying t-test and logistic regression analysis. Results We identified 387 and 787 monkeys with and without drusens, respectively. Among them, 317 and 628 monkeys with and without drusens that had a complete biological data set were further studied. After comparing each parameter in monkeys with and without drusens, 13 factors with a significance of P < 0.1 (t-test) were selected for logistic regression analysis. Regression analysis showed association of age (odds ratio: 1.092, 95% confidence interval: 1.061–1.125) and platelet count (odds ratio: 1.022, 95% confidence interval: 1.005–1.038) with drusens. In addition, an association was implicated between drusens and white blood cell count (odds ratio: 1.005, 95% confidence interval: 1.000–1.011). Conclusions Age, platelet count, and white blood cell count may be associated with the development of drusens in Macaca fascicularis.