Clinical feasibility of hyperspectral imaging for evaluation of anterior segment disorders

To evaluate the feasibility of hyperspectral imaging (HSI) for non-invasive characterization of pathological conditions in the human anterior segment and to explore its use alongside laser speckle contrast imaging (LSCI) for consecutive assessment of oxygenation and perfusion.

23 patients were examined with HSI and/or LSCI prior to evisceration or enucleation. HSI recorded diffusely backscattered light from the conjunctiva/sclera, iris/cornea, and pupil/retina regions. Spectra were interpreted using reference tissue scattering and absorption signatures from which changes in oxygen saturation and total hemoglobin were determined. LSCI was used to assess perfusion. Spectral and perfusion data from eyes with conjunctival hyperemia, corneal opacity, and corneal hemosiderosis were compared with reference anterior segments.

Spectral differences were observed with HSI for the major anatomical regions of the anterior segment. Spectra were interpreted in relation to known chromophore-associated spectral features of the examined tissue. Hyperemic eyes showed an increase in hemoglobin-related absorption, while opaque or hemosiderotic corneas exhibited flattening of the spectra, characteristic of increased light scattering and an obscured melanin absorption. Perfusion demonstrated a high spatial correlation with the signal related to total hemoglobin. In hyperemic eyes, perfusion and total hemoglobin were elevated while oxygen saturation remained stable, indicating compensatory regulation.

This feasibility study demonstrates the potential of HSI for non-invasive characterization of physiologically relevant spectral signatures in the human anterior segment. Together with consecutive LSCI measurements, HSI provides independently acquired physiological insights on perfusion and oxygenation. With larger studies, HSI could reveal how pathological conditions evolve at a biological level.