Photodynamic eye

Lymphatic structures in the hindlimbs of the control and roxadustat groups were compared by fluorescent lymphography every week for 4 weeks postoperatively (n = 6 per group). Prior to imaging, isoflurane was used to anesthetize the mice and their residual fur was removed. A 5-μL volume of indocyanine green solution (2.5 mg/mL Diagnogreen in distilled water; Daiichi Sankyo Company, Ltd., Tokyo, Japan;) was subcutaneously injected into both paws with a 26-gauge needle. Imaging was performed indocyanine green using a near-infrared fluorescence camera system (Photodynamic Eye; Hamamatsu Photonics, Hamamatsu, Japan) 15 min after indocyanine green injection. The coverage of the fluorescent area (i.e., the dermal backflow at the thigh) was measured using ImageJ software (National Institutes of Health).

Testing was carried out at a room temperature of 20 °C-25 °C with the patient resting in a supine position; 25 mg ICG (Diagnogreen ™ ; Daiichi-Sankyo Pharmaceutical, Tokyo, Japan) was dissolved in 25 mL distilled water (Otsuka distilled water ™ ; Otsuka Pharmaceutical, Tokyo, Japan) and 0.1 mg/kg of the mixture was injected via the cubital vein. Fluorescence photography was then immediately conducted using an infrared camera system (Photodynamic Eye ™ , Hamamatsu Photonics K.K., Hamamatsu, Japan). Infrared rays activate ICG and emit light weaker than 820 nm (10) . A light-emitting diode of 760 nm was used as the light source to irradiate ICG, with a charge-coupled device (CCD) camera used as the detector. The camera system was placed in a position approximately 20 cm from the skin of the feet, filming was carried out for 5 min following ICG injection, and real-time fluorescence imaging was shown on a monitor and recorded using an audio video interweave system. Thereby, the time-intensity curve was measured. ICG is non-toxic and side effects rarely occur (1/40,000); no abnormalities in the hemodynamics were observed in any case, and the pulse and blood pressure were within normal ranges (11) .