We develop an information-theoretic framework for the quantitative assessment of the maximum amount of information provided by optical coherence imaging through scattering media. We use our approach to investigate the fundamental dependence of the extractable information on the nature of the coherent imaging process, such as on speckle formation. We present nontrivial predictions for the maximum amount of information detected by optical coherence tomography (OCT) from within homogeneous and heterogeneous scattering media and explore its behavior against coherence length and dimension of the detection array. Extension to additional coherent and incoherent light imaging approaches is also discussed.