息肉状脉络膜血管病变(polypoidal choroidal vasculopathy,PCV)是亚洲人群中常见的致盲性眼病，发生大出血并发症后严重危害视力且预后差。PCV大出血包括视网膜下出血(subretinal hemorrhage,SRH)和玻璃体积血(vitreous hemorrhage,VH)。SRH的危险因素包括较长病程、簇型PCV、息肉状病灶不消退、合并视网膜色素上皮脱离；其治疗方式包括抗血管内皮生长因子药物、光动力疗法、激光、玻璃体腔注气、眼内注射组织纤溶酶原激活剂、玻璃体切割术或联合治疗等方式，其中，黄斑中心凹是否受累和出血时间是影响治疗方式选择的主要因素。发病年龄较大、白细胞计数较高、天门氨酸转移酶和丙氨酸转氨酶的比值较高、活化部分凝血活酶时间较长、曾行光动力疗法、有玻璃体腔注药治疗史、SRH面积大、出现视网膜色素上皮脱离的PCV患者发生VH的风险高。浓厚的VH通常需行玻璃体切割术，其手术时机和手术方式的选择是临床关注的焦点。鉴于目前PCV大出血的危险因素尚不完全明确、治疗方面也尚未形成共识，需要开展相关临床研究，提供更多依据。

Polypoidal choroidal vasculopathy (PCV) is a common blinding disease in Asian populations. Massive hemorrhage complications secondary to PCV include subretinal hemorrhage (SRH) and vitreous hemorrhage (VH). The risk factors for SRH include a long duration, clustered PCV, non-regression of polyp lesions and presented with retinal pigment epithelial detachment. The treatments for SRH include anti-vascular endothelial growth factor drugs, photodynamic therapy, laser, vitreous pneumatic displacement, intravenously injected tissue plasminogen activator, vitrectomy and combination therapy. Whether macular fovea is involved and the time since bleeding onset are the main factors afecting the choice of treatment for SRH. Older age of onset, higher white blood cell count, higher aspartate amino transferase and alanine amino transferase ratio, longer activated partial thromboplastin time retinal pigment epithelium detachment, photodynamic therapy history, intravitreal injection history larger SRH area and presented with retinal pigment epithelial detachment were associated with higher risk of VH. PCV patients with massive VH should be treated with vitrectomy, while the timing and technique of operation should be paid atention to. At present, the risk factors of PCV massive bleeding are not completely clear, and its treatment methods are diverse, which requires a large number of studies to prove its effectiveness and establish expert diagnosis and treatment consensus.

息肉状脉络膜血管病变（polypoidal  choroidal vasculopathy, PCV）是中国人新生血管性年龄相关性黄斑变性的(age-related macular degeneration, AMD)主要亚型。PCV与典型的新生血管性AMD在流行病学、临床表现、影像学特征和自然病程方面存在一定差异。近年来的研究表明，除了传统的玻璃膜疣驱动机制外，PCV可能与肥厚脉络膜机制相关，后者在亚洲人群中更为常见。深入的病理学探索将有助于揭示PCV的发病机制，并探索PCV与其他脉络膜疾病之间的内在联系。由于PCV患者眼球标本的稀缺，现有的病理学研究较少，且结果之间存在一定差异。文章通过介绍笔者最新的临床病理研究结果，并结合历年来国内外的研究，总结了关于PCV病灶所在的层次、起源及血管内皮生长因子（vascular endothelial growth factor, VEGF）表达水平的争议问题，阐明了PCV的临床病理研究现状。第一，PCV病灶的层次。临床上，OCT成像显示PCV病灶位于视网膜色素上皮（retinal pigment epithelium, RPE）与Bruch膜的高反射线之间，属于I型脉络膜新生血管的特殊亚型。部分病理学研究认为PCV病灶位于Bruch膜内，但实际上PCV病灶更准确地位于RPE基底膜下。第二，异常分支血管网（branching vascular networks, BVN）的起源。尸体眼标本的病理分析表明，BVN起源于脉络膜动脉，且动脉穿过Bruch膜后，转变为薄壁毛细血管形成I型脉络膜新生血管。少数研究指出PCV可能由静脉扩张形成，并存在脉络膜静脉的淤滞。第三，VEGF在PCV病灶中的表达。VEGF是新生血管性AMD的关键致病因子，一些研究表明PCV病灶中VEGF表达升高，提示PCV可能与新生血管性AMD具有相似的发病机制，但也有研究发现PCV病灶中的VEGF表达为阴性，提示PCV的机制可能不完全依赖于VEGF。综上，PCV的病理特征具有复杂性，既有与新生血管性AMD相似的表现，也有肥厚脉络膜的特征。随着眼球捐献意识的提高，未来有望获得更多宝贵的眼球标本，为进一步探索PCV的发病机制提供支持,并为其临床诊断和治疗提供更有效的策略。

Polypoidal choroidal vasculopathy (PCV) is the main subtype of neovascular age-related macular degeneration (AMD) in China.  PCV differs from typical neovascular AMD in terms of epidemiology, clinical presentation, imaging features, and natural disease course. Recent studies suggest that, in addition to the traditional drusen-driven mechanism, PCV may also be associated with pachychoroid mechanism, which is particularly more common in Asian populations. In-depth pathological research will help uncover the pathogenesis of PCV and explore the intrinsic connections between PCV and other choroidal diseases. Due to the rarity of eye specimens from PCV patients, there is limited pathological research, and results can vary. Herein, this article summarize the controversial issues regarding the location level, origin, and the vascular endothelial growth factor (VEGF) expression of PCV lesions by introducing our latest clinicopathologic study on PCV and combining with previous studies in China and worldwide. First, the layer of PCV lesions. Clinically, OCT imaging shows that PCV lesions are located between the retinal pigment epithelium (RPE) and the hyperreflective line of Bruch membrane, making them a special subtype of type I choroidal neovascularization. Some pathological studies suggest that PCV lesions are located within Bruch membrane, but in fact, PCV lesions are more accurately located beneath the RPE basement membrane. Second, the origin of the branching vascular networks (BVN). Pathological analysis of postmortem eye specimens indicates that BVN originates from choroidal arteries, and after passing through Bruch membrane, they transform into thin-walled capillaries, forming type I choroidal neovascularization. A few studies suggest that PCV may result from dilation of choroidal vein, accompanied with vein stasis. Third, VEGF expression in PCV lesions. VEGF is a key pathogenic factor in neovascular AMD. Some studies show increased VEGF expression in PCV lesions, suggesting that PCV may share a similar pathogenic mechanism with neovascular AMD. However, other studies have found negative VEGF expression in PCV lesions, indicating that the mechanism of PCV may not be entirely dependent on VEGF. In conclusion, the pathological features of PCV are complex, showing both similarities to neovascular AMD and characteristics of pachychoroid. With the increasing awareness of eye donation, more valuable eye specimens are expected to be obtained in the future, providing support for further ex;ploration of the pathogenesis of PCV and offering more effective strategies for its clinical diagnosis and treatment.

      息肉状脉络膜血管病变(polypoidal choroidal vasculopathy,PCV)是亚洲人群中常见的致盲性眼病，发生大出血并发症后严重危害视力且预后差。PCV大出血包括视网膜下出血(subretinal hemorrhage,SRH)和玻璃体积血(vitreous hemorrhage,VH)。SRH的危险因素包括较长病程、簇型PCV、息肉状病灶不消退、合并视网膜色素上皮脱离；其治疗方式包括抗血管内皮生长因子药物、光动力疗法、激光、玻璃体腔注气、眼内注射组织纤溶酶原激活剂、玻璃体切割术或联合治疗等方式，其中，黄斑中心凹是否受累和出血时间是影响治疗方式选择的主要因素。发病年龄较大、白细胞计数较高、天门氨酸转移酶和丙氨酸转氨酶的比值较高、活化部分凝血活酶时间较长、曾行光动力疗法、有玻璃体腔注药治疗史、SRH面积大、出现视网膜色素上皮脱离的PCV患者发生VH的风险高。浓厚的VH通常需行玻璃体切割术，其手术时机和手术方式的选择是临床关注的焦点。鉴于目前PCV大出血的危险因素尚不完全明确、治疗方面也尚未达成共识，需要开展相关临床研究，提供更多依据。

      息肉状脉络膜血管病变(polypoidal choroidal vasculopathy,PCV)是亚洲人群中常见的致盲性眼病，发生大出血并发症后严重危害视力且预后差。PCV大出血包括视网膜下出血(subretinal hemorrhage,SRH)和玻璃体积血(vitreous hemorrhage,VH)。SRH的危险因素包括较长病程、簇型PCV、息肉状病灶不消退、合并视网膜色素上皮脱离；其治疗方式包括抗血管内皮生长因子药物、光动力疗法、激光、玻璃体腔注气、眼内注射组织纤溶酶原激活剂、玻璃体切割术或联合治疗等方式，其中，黄斑中心凹是否受累和出血时间是影响治疗方式选择的主要因素。发病年龄较大、白细胞计数较高、天门氨酸转移酶和丙氨酸转氨酶的比值较高、活化部分凝血活酶时间较长、曾行光动力疗法、有玻璃体腔注药治疗史、SRH面积大、出现视网膜色素上皮脱离的PCV患者发生VH的风险高。浓厚的VH通常需行玻璃体切割术，其手术时机和手术方式的选择是临床关注的焦点。鉴于目前PCV大出血的危险因素尚不完全明确、治疗方面也尚未达成共识，需要开展相关临床研究，提供更多依据。

息肉样脉络膜血管病变(polypoidal choroidal vasculopathy,PCV)是一种以脉络膜异常分支血管网和血管末端息肉状脉络膜血管扩张灶为特征的眼底疾病。(indocyanine green angiography,ICGA)是诊断PCV的金标准，可见异常分支血管网、息肉样高荧光。(optical coherence tomography,OCT)可见色素上皮脱离(pigment epithelial detachments,PED)、双层征、指状突起、PED切迹、脉络膜增厚等。基于 OCT 的影像学研究表明，PCV属于肥厚型脉络膜谱系疾病(pachychoroid disease spectrum,PCD)，其特征是脉络膜增厚、脉络膜大血管层(Haller层)扩张，伴有毛细血管层(Ruysch层)和中血管层(Sattler层)变薄，其发病机制可能涉及脉络膜、涡静脉、巩膜等相关改变。

息肉状脉络膜血管病变(polypoidal choroidal vasculopathy，PCV)是亚洲人中常见的眼底致盲性疾病，当PCV合并视网膜下出血或玻璃体积血(vitreous hemorrhage，VH)时，患者视力骤然下降，视力预后差异大。但目前聚焦于PCV合并VH的相关文献较少，因此研究和阐明PCV继发VH的治疗方法及预后具有重要的临床意义。目前临床上常选择手术干预，玻璃体切除术(pars plana vitrectomy，PPV)是临床上最常选择的一种术式。其他治疗方式包括玻璃体内注射抗血管内皮生长因子(vascular endothelial growth factor，VEGF)、眼内气体或硅油填充、眼内注射组织纤溶酶原激活剂(tissue plasminogen activator，tPA)和光动力疗法(photodynamic therapy，PDT)。PCV合并VH患者的视力预后决定因素是黄斑视功能的保留程度，也与年龄、术前视力、PCV病变部位、视网膜下出血量、视网膜脱离范围、基线黄斑中心厚度(central macular thickness，CMT)、是否出现术后并发症以及是否形成视网膜瘢痕等因素相关，目前也有研究发现视力预后与单核苷酸多态性(single nucleotide polymorphisms，SNP)相关。本文就PCV继发VH的临床特点、治疗及预后进行综述。

Polypoid choroidal vasculopathy (PCV) is a common fundus blinding disease in Asians. When PCV is associated with subretinal hemorrhage or vitreous hemorrhage (VH), patient's visual acuity decreases suddenly and the visual prognosis varies greatly. There are few relevant literatures focusing on VH secondary to PCV, so it is of great clinical significance to study and clarify the treatment methods and prognosis of VH secondary to PCV. At present, surgical intervention is often selected in clinical practice. Vitrectomy is the most commonly selected surgical procedure in clinical practice. The other treatment modalities include intravitreal injection of antivascular endothelial growth factor (VEGF), intraocular gas or silicone oil filling, intraocular injection of tissue plasminogen activator (tPA) and photodynamic therapy. The prognostic determinant of visual acuity in PCV

patients with VH is the degree of preservation of macular visual function. The prognostic is also related to age, preoperative visual acuity, PCV lesion location, amount of subretinal hemorrhage, extent of retinal detachment, baseline central macular thickness (CMT), postoperative complications and retinal scars. Recent studies also find that the prognosis of visual acuity is related to single nucleotide polymorphisms. This article reviews the clinical characteristics, treatment and visual prognosis of PCV associated with VH.