The retinal blood oxygen quantification method is a fast and non-invasive new retinal vascular imaging technology, which is used to reflect the metabolism of retinal blood oxygen and the micro-circulation of whole body by measuring, analyzing and quantifying the blood oxygen saturation of the main arteries and veins of the retina. The circulation state provides a reliable basis for medical diagnosis. Retinal blood oxygen saturation can be used as a biomarker for the diagnosis and evaluation of ophthalmologic and brain diseases such as diabetic retinopathy, central retinal vein occlusion, retinitis pigmentosa, glaucoma and Alzheimer's disease.
ObjectiveTo develop a simple and effective subretinal injection pipeline system to enhance the accuracy and precision of subretinal injection volume control. MethodA retrospective case series study. From May to October 2023, 18 patients (18 eyes) with submacular hemorrhage (SMH) who continuously received modified subretinal injection treatment in Department of Ophthalmology of Peking Union Medical College Hospital were included in the study. Among them, there were 10 males and 8 females. Age were (60.00±7.41) years old. The primary causes included polypoid choroidal vasculopathy (14 cases), retinal macroaneurysm (2 cases), traumatic retinopathy (1 case), and Valsalva retinopathy (1 case). Hemorrhage affected 14 eyes of the fovea centralis. All affected eyes underwent standard three-channel 25G vitrectomy via the flat part of the ciliary body combined with modified subretinal injection of recombinant tissue plasminogen activator. The improved injection system consisted of a 1 ml syringe, a Q-SyteTM connector, a 41G subretinal microinjection needle, a converter and a viscoelastic substance control pipeline. The drug preparation time for subretinal injection (i.e., the time consumed by the system connection step), the injection time, whether bubbles occur during the injection process, and the perioperative complications were recorded and analyzed. ResultThe preparation time prior to drug injection ranged from 231 to 335 seconds, while the injection completion time varied between 45 and 75 seconds. Both times decreased progressively as operator proficiency improved. Among the treated eyes, five received a target injection dose of 0.05 mL and thirteen received 0.10 mL, with all eyes achieving the preset dose accurately. No subretinal bubbles were observed during the injection procedure. Additionally, no intraoperative complications such as retinal hemorrhage or tear secondary to mechanical trauma at the injection site were recorded. Postoperatively, one eye developed anterior chamber hemorrhage, which resolved following intraocular pressure-lowering treatment. No other postoperative complications, including hemorrhage, rhegmatogenous retinal detachment, or infection, were observed in the remaining eyes. ConclusionThe retinal drug injection system developed in this study has a simple structure, safe and stable operation, can achieve precise drug injection, and effectively avoid the formation of bubbles.