A diagnostic sign refers to a quantifiable biological parameter that is measured and evaluated as an indicator of normal biological, pathogenic, or pharmacologic responses to a therapeutic intervention. When used in translational research discussions, the term itself often alludes to a sign used to accelerate or aid in diagnosis or monitoring and provide insight into “personalized” medicine. Many new diagnostic signs are being developed that involve imaging technology. Optical coherence tomography is an imaging technique that provides in vivo quasi-histological images of the ocular tissues and as such it’s able to capture the structural and functional modifications that accompany inflammation and infection of the posterior part of the eye. From the hyperreflective inflammatory cells and deposits in the vitreous and on the hyaloid, to the swollen photoreceptors bodies in multiple evanescent white dots syndrome, and from optical differences in the subretinal fluid compartments in Vogt-Koyanagi-Harada disease to the hyporeflective granulomas.

Reference link- https://www.sciencedirect.com/science/article/abs/pii/S135094621930031X