C4A and age-related macular degeneration: On comparing subgroups of nAMD participants with controls, there was a significant increase in C3a, C4a and C5a in those with CNV when compared to controls in the univariate analysis (P < 0.001, P = 0.003 and 0.044 respectively; Table 3) and these associations remained significant in the multivariate analysis after correction for age and gender as well as family history of AMD for C3a and C4a (P = 0.001, 0.009 and 0.008 respectively).