Graphical representation of four representative clinical cases.

Each row comprises a SD-OCT cross-sectional ‘Line’ image of a typical in vivo human cornea with corresponding flattened and normalized image (the apex-centered ROI appears as a red dotted frame), the associated mean intensity depth profile and mono-exponential fitting analysis (see [11] for further details on fitting analysis). (A, B) Normal corneas (0.0 logMAR visual acuity) from our n = 83 sample with comparable Birge ratios, but (B) shows a faster decaying stromal depth profile and thus has a lower photon mean-free path (ℓs) and associated fraction of transmitted coherent light (Tcoh(stroma)). (C, D) Pathological corneas with compromised transparency as per “gold-standard” subjective and qualitative image inspection, with (C, Fuchs dystrophy) showing homogeneous scattering in the stroma (Brcoh(stroma), and (D, keratoconus) with visible heterogeneities (very heterogeneous scattering) in the stroma (Br≫ 10); transparency assessment via a mono-exponential fitting of the in-depth profile is hence inadequate. Scale bar lengths: 500 μm.