Figure 2

Schematic illustration of paper-based ELISA for VEGF detection.
In the clinical setting, patients receive standard-of-care procedures: slit lamp, SD-OCT, and FAG (left panel). Paper-based ELISA requires 1 μL of aqueous humor before operation, and quantification of VEGF concentrations requires 40 μL (right panel). Further colorimetric results can be obtained using a scanner or smartphone. Ophthalmologists can determine treatment according to VEGF concentrations and SD-OCT results.