Figure 3.

Markers of ONH vascular leakage in rNAION. (A,B). Baseline retinal fundus photos taken 30 s post-intravenous dye injection in a naïve (uninduced) animal of A. Fluorescein (IVFA). The intraretinal veins (Ve) and arteries (Ar) are visible, but the optic nerve circulation is muted due to the presence of melanin pigment, which blocks visible light. (B). Indocyanine green (ICGA). ICG fluorescence is visualized via infrared light, which passes through melanin. The choroidal circulation below the retinal pigment epithelium is clearly visible, as is the enhanced circulation around the ON. (C). fluorescein dye fluorescence 5 min post-injection. The ONH is barely visible. (D). ICG fluorescence 5 min post-injection. No leakage is visible. (E–J): fluorescein and ICG image pairs of the same eyes in three animals (Y543, Y544, Y545) taken 5 h post-rNAION induction. There are significant differences in the amount of post-injection fluorescence revealed by the two dye types. In general, the ICG dye signal is more stable, due to its nearly 100% binding to serum proteins and reduced diffusion. The ICG patterns are indicative of the deeper leakage in the ONH. The circle in plate (J) is 500 µm. Data for Figure 3 is reprinted with permission from [16]. 2021 PLOS-One.