The nature of blazar gamma-ray emission still remains uncertain, in particular whether it is of a leptonic or hadronic origin. Here, we are testing the leptonic scenario for the Flat Spectrum Radio Quasar
(FSRQ) 3C 279, with the inverse Compton (IC) scattering of external photons from the Broad Line Region (BLR) as the gamma-ray production mechanism (IC-BLR scenario). Using a 10-year data set of the optical spectroscopy data from the Steward Observatory blazar monitoring program and Fermi-LAT gamma-ray data, we search for a correlation between the Compton dominance and the emission line luminosity using the discrete correlation function (DCF) analysis. We find no significant correlation between these quantities at any time lag. However, the emission line luminosity moderately correlates with gamma-ray flux at zero time lag. Additionally, we observe a strong correlation between the optical synchrotron continuum flux and gamma-ray flux. These results support the interpretation within the leptonic IC-BLR scenario, where changes in the magnetic field and/or the bulk Lorentz factor drive the variations in Compton dominance rather than changes in the emission line luminosity.