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.
Objective To analyze the results of diagnostic pars plana vitrectomy (PPV) in patients with uveitis of unknown cause. Methods This is a retrospective case series study. Sixty-five patients (67 eyes) with uveitis of unknown cause were enrolled in this study. There were 31 males (32 eyes) and 34 females (35 eyes). The ages were from 6 to 84 years, with the mean age of (55.00±18.56) years. All eyes were received PPV. Examination of vitreous samples consisted of microbial stains and culture, microbial DNA and antibody detection, cytokine measurement, cytology, flow cytometry and gene rearrangement detection. Results Vitreous analysis was positive in 40 of 67 eyes (59.7%). Positive results indicated bacterial endophthalmitis in 20 of 40 eyes (50.0%), lymphoma in 11 eyes (27.5%), viral IgM and IgG increased significantly in 3 eyes (7.5%), fungal endophthalmitis in 3 eyes (7.5%), IgG of toxocara increased significantly in 2 eyes (5.0%), IgG of toxoplasma Gondii increased significantly in 1 eye (2.5%). Conclusion The diagnostic yield of vitreous samples in uveitis eyes of unknown cause is 59.7%.