ObjectiveTo develop a simple and effective subretinal injection pipeline system to enhance the accuracy and precision of subretinal injection volume control. MethodsA 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. The mean age was (60.00±7.41) years. 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. ResultsThe preparation time prior to drug injection ranged from 230 to 335 seconds, while the injection completion time varied between 43 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.
Polypoidal choroidal vasculopathy (PCV) is originally defined as a separate disease, but with the development of imaging techniques, it has now been included in the spectrum of neovascularization. In the Asian population, the prevalence of PCV is high, and with the deepening of clinical studies, the pathological characteristics, pathogenesis and clinical manifestations of PCV have been more deeply understood. Through dynamic observation and histopathological study of PCV lesions during operation, it can be confirmed that the lesions are mainly located between the retinal pigment epithelium and the Bruch membrane, rather than originating from the choroidal circulation, which is of great significance for understanding the origin and natural course of PCV. It is worth noting that although a theoretical bridge has been established between age-related macular degeneration (AMD)/PCV, there is a lack of intuitive clinical data on the ultrastructural and molecular manifestations of the cells/stroma in the local lesions of the eye, especially the progression of AMD/PCV from early/middle stage to exudative stage. It is precisely because of this that highly attractive research topics and exploration space are proposed for the future.
The venous overload chorioretinal lesion (VOC) hypothesis provides a new perspective for understanding the thick choroidal spectrum disorders (PSD). This hypothesis posits that the obstruction of choroidal venous outflow is the common pathophysiological basis of PSD. The pathogenesis of VOC includes: anatomical basis (the tortuous veins are similar to "Starling resistors", with outflow obstruction leading to venous hypertension and the exacerbation of low intraocular pressure); pathophysiological cascade reaction (venous hypertension triggers venous dilation and remodeling, forming "thick-walled vessels", abnormal anastomosis, and high vascular permeability, ultimately resulting in choroidal thickening, subretinal fluid accumulation, and neovascularization). In addition, multimodal imaging techniques such as swept-source optical coherence tomography (OCT) and OCT angiography play a crucial role in the diagnosis and treatment of VOC, enabling the identification of various imaging biomarkers, such as morphological markers (thick-walled vessels, retinal detachment sign, tortuous veins interanastomosis, choroidal thickness, etc.) and hemodynamic markers (choroidal vascular index, choroidal capillary blood flow, choroidal vascular high permeability, etc.), which are helpful for diagnosis, differentiation, assessment of disease activity, prediction of prognosis, and guidance for individualized treatment. The treatment strategy should shift from simply draining fluid to reducing venous load and restoring blood flow balance. Based on the disease manifestations and imaging biomarkers, treatment options can be selected, such as photodynamic therapy, anti-vascular endothelial growth factor (VEGF) drugs, laser photocoagulation for leakage predominant cases, or anti-VEGF drugs combined with photodynamic therapy or monotherapy for neovascularization cases. Future research directions include further elucidating the complex pathogenesis of VOC (such as upstream arterial perfusion factors, abnormal neurovascular regulation), developing etiological-targeted therapies (reducing venous resistance, improving tortuous vein outflow function), using artificial intelligence to integrate multimodal imaging and genomics data to establish a precise decision-making system, and strengthening disease prevention and long-term management. The VOC hypothesis provides a theoretical basis for the precise diagnosis and treatment of PSD. With the deepening of research and the development of new therapies, it will promote the diagnosis and treatment of choroidal-retinal diseases into an era of precision medicine centered on hemodynamics.
ObjectiveTo observe and analyze the subfoveal choroidal thickness (SFCT), large choroidal vessel layer thickness (LCVT), and their early changes, and to evaluate their prognostic value for treatment outcomes in eyes with polypoidal choroidal vasculopathy (PCV) receiving anti-vascular endothelial growth factor (VEGF) therapy. MethodsA retrospective clinical study. A total of 120 patients (120 eyes) with unilateral PCV diagnosed and confirmed at Tangshan Eye Hospital from January 2020 to August 2024 were included. All affected eyes received intravitreal anti-VEGF injections. SFCT and LCVT were measured using swept-source optical coherence tomography (SS-OCT) before treatment and at 1, 3, 6, and 12 months after treatment. Based on the 12-month follow-up outcomes, the eyes were divided into a good prognosis group (69 eyes) and a poor prognosis group (51 eyes). Subretinal fluid (SRF) absorption was assessed by SS-OCT at 1 month after the first treatment (early stage). Repeated measures ANOVA was used to compare the dynamic changes of SFCT and LCVT between the two groups. Binary logistic regression, joint modeling, receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and mediation analysis were used to evaluate the predictive value of SFCT and LCVT for prognosis. ResultsCompared with the good prognosis group, the poor prognosis group had significantly greater disease duration, best-corrected visual acuity, branching vascular network area, maximum linear lesion distance, proportion of choroidal vascular hyperpermeability, pigment epithelial detachment height, and pre-treatment SFCT and LCVT (P＜0.05). The good prognosis group had significantly lower SRF height (SRFH) before treatment and at 1 month after treatment, and a greater reduction in SRFH (ΔSRFH) within the first month, compared with the poor prognosis group (P＜0.05). At 1 month after treatment, complete SRF absorption was observed in 65 eyes (94.20%, 65/69) in the good prognosis group and 32 eyes (62.75%, 32/51) in the poor prognosis group; the complete SRF absorption rate was significantly higher in the good prognosis group (χ2=18.731, P＜0.001). Repeated measures ANOVA showed that SFCT and LCVT significantly decreased after treatment at different time points in both groups (P＜0.05); at each post-treatment time point, SFCT and LCVT were significantly higher in the poor prognosis group than in the good prognosis group (P＜0.05). Cohen's d effect size analysis showed that the intergroup difference in LCVT was greater than that in SFCT. ROC curve analysis showed that pre-treatment SFCT and LCVT effectively predicted early complete SRF absorption, and LCVT had significantly better diagnostic performance than SFCT [area under the ROC curve (AUC)=0.82, 0.76; P=0.025]. Joint modeling analysis showed that longitudinal changes in SFCT and LCVT were significantly associated with the risk of poor prognosis (P＜0.01); for every 50 μm increase in LCVT and SFCT, the relative risk of poor prognosis was 1.615 and 1.512, respectively. The Akaike information criterion value of the LCVT joint model (3 719.42) was lower than that of the SFCT model (3 852.67). At 1 month after treatment, ΔLCVT and ΔSFCT were both significant predictors of poor prognosis; in all adjusted models, the odds ratio of ΔLCVT was lower than that of ΔSFCT, indicating better predictive value. ROC curve analysis showed that both ΔSFCT and ΔLCVT had significant predictive value for poor prognosis, and ΔLCVT had significantly better predictive performance than ΔSFCT (AUC=0.81, 0.74). DCA showed that both ΔSFCT and ΔLCVT provided clinical net benefit, with ΔLCVT showing higher benefit. Mediation analysis showed that ΔLCVT and ΔSFCT partially improved prognosis by promoting early SRF absorption, with the indirect effect of ΔLCVT (39.35%) being higher than that of ΔSFCT (32.70%). ConclusionsBoth SFCT and LCVT can serve as predictors of prognosis in PCV eyes treated with anti-VEGF therapy. After controlling for the effect of SFCT, LCVT maintains independent predictive value, and its predictive efficacy is superior to that of SFCT.