Figure 1.

Summary of liquid biopsy techniques for ophthalmic tissues: cross sectional image of the human eye. (A) The vitreous is an extracellular matrix that covers the retina, lens, and ciliary body. The vitreous core is biopsied using a 23-gauge needle (depicted) or vitreous cutter and contains native vitreous proteins, systemic protein biomarkers, and retinal biomarkers that can be sampled through proteomic analysis. (B) The aqueous humor, located in the anterior chamber of the eye, is produced by the ciliary body. A 25-gauge needle can be inserted into the anterior chamber at the limbus to sample the aqueous humor for proteomic analysis. Graphical illustrations by Alton Szeto and Vinit Mahajan. Permission to publish granted by original artist.