PURPOSE: Previous findings indicate that patients with myeloproliferative neoplasms (MPN) exhibit elevated levels of inflammatory biomarkers and have a high prevalence of AMD. In this study, we aim to determine whether drusen and systemic inflammation in patients with MPN affect macular sensitivity in the same manner as in patients with AMD. METHODS: The study was conducted as a prospective cross-sectional study. A total of 139 study eyes of 71 patients were included in this study. We measured macular sensitivity using microperimetry and extracted blood samples to evaluate systemic inflammation markers. RESULTS: Multilevel linear mixed-effect analysis did not show any difference in macular sensitivity when comparing eyes of MPN patients with AMD to those without drusen (β = -0.254, P = 0.657). However, higher levels of the complement system fragment C5a were significantly correlated with decreased total macular sensitivity (β = -0.561, P = 0.027), irrespective of the presence of drusen. CONCLUSIONS: We found that high levels of the systemic inflammation marker C5a are associated with reduced macular sensitivity, regardless of the presence of visible degenerative changes in the macular area. These findings suggest an early contribution of the complement system to macular sensitivity.