In the 20 years since Yannuzzi published his landmark paper “Idiopathic polypoidal choroidal vasculopathy (PCV)” in 1990, PCV has become a very hot topic in the fundus community. The number of articles available on Pubmed shows a geometric increase in the number of articles published on PCV. During the decade 1990-1999, only 16 articles were published in Pubmed, while more than 500 articles have been published since 2000, not including non-Pubmed articles. The Asian region, in particular, appears to be more active in the field of PCV because the prevalence of PCV is much higher than the prevalence in Caucasian populations. But even so, the pathological mechanisms, diagnosis and treatment regarding PCV remain our challenge. I. Is PCV an independent disease or a subtype of AMD? Yannuzzi named the lesion PCV because he believed it to be an independent disease. Evidence in support of its independent status includes: (1) the prevalence of PCV is significantly higher in people of color than in Caucasians; (2) although few, studies of pathogenic gene polymorphisms have identified some loci that are highly associated with PCV but not AMD. (3) Differences in clinical manifestations, such as vitreous warts, extensive subretinal hemorrhage and plasma blood retinal pigment epithelial detachment are more commonly seen in patients with PCV, and characteristic orange-red nodule-like lesions can be seen in the fundus. (4) Indocyanine green angiography reveals characteristic hemangioma-like dilated structures or/and an abnormal branching vascular network. (5) OCT reveals the so-called “double layer sign” and choroidal thickening (hyperpermeability), which is absent in age-related macular degeneration. Evidence in favor of PCV as a subtype of AMD includes: (1) most patients are over 50 years of age; (2) clinical manifestations such as hemorrhage, exudation, and retinal pigment epithelial detachment can be seen in both AMD and PCV; (3) many studies on genetic polymorphisms of AMD and PCV have found many genetic polymorphic variants associated with both AMD and PCV such as ARMS2 / HTRA1 rs10490924 (A69S) locus and rs11200638.(4) Although some pathological and immunohistochemical reports have found hyaline degeneration of choroidal vessels in PCV specimens and negative staining for VEGF antibodies, suggesting that the abnormal vessels of PCV may be different from choroidal neovascularization, there is no sufficient evidence so far to prove that the pathological mechanisms of the two are different and that the abnormal vessels of PCV are neovascular or normal. Whether the abnormal vessels of PCV are neovascularization or lesions of normal choroidal vessels or both remains uncertain. Therefore, it is worthwhile to conduct a more in-depth study to clarify whether PCV is an independent disease or a subtype of AMD from both clinical and genetic perspectives. The diagnosis of PCV basically follows the consensus of the Asia-Pacific experts on PCV, which is mainly based on the findings of indocyanine green angiography, i.e., angiomatous dilated vascular structures, so-called “polyp-like lesions”, should be found within the first 5 minutes of the angiography, and if no such structures are found, it can only be a proposed or suspected diagnosis. Diagnosis. In Japan, there is no consensus on the diagnostic criterion that an orange-red nodular lesion is diagnosed if found on fundus examination. There are indeed many ambiguous clinical cases, such as large subretinal hemorrhages and large cases of plasmacytic detachment, where ICGA does not show typical lesion structures, how to diagnose? With the absorption of the hemorrhage or the prolongation of the disease, typical lesions were eventually found in some cases; in a few cases, typical abnormal branching vascular networks could be seen, but there were no polyp-like lesions, was it PCV?There were also many lesions between the abnormal PCV vessels and choroidal neovascularization, which were still challenging to diagnose. In China, because the diagnostic criteria are not fully unified, there is a great bias in the clinical statistics of prevalence, which is an issue that needs to be addressed in the future. It is worth mentioning that the application of high-resolution OCT has provided a very good diagnostic aid for PCV, for example, the OCT examination found that the polypoid lesions are characterized by high and narrow finger-like protrusions of the RPE and the so-called “double-layer sign”, i.e., the inner layer is The inner layer is a highly reflective band of flat or wavy elevated RPE, the outer layer is a thin and straight highly reflective band of Bruch’s membrane, and the middle is a homogeneous or heterogeneous moderate or hypo-reflective OCT image. These two OCT findings are helpful in confirming the diagnosis of certain cases of ICGA with ambiguous diagnosis and cases of massive subretinal hemorrhage, and it is recommended to pay attention to the value of OCT in the diagnosis of PCV. Third, the treatment of PCV: photodynamic therapy or anti-VEGF? Regarding the treatment choice of PCV, we have been promoting the PDT-led treatment guideline. If the PCV lesion is located outside the central macular sulcus, laser photocoagulation therapy can be considered. The evidence for this cornerstone comes from the EVEREST study, a 6-month clinical study that showed that photodynamic therapy alone resulted in the regression of more than 70% of polypoid lesions, while less than 30% of polypoid lesions regressed with anti-VEGF vitreous injection alone. The shortcoming of the EVEREST study is that the treatment observation period is too short, and there are many studies showing that the recurrence rate of PDT treatment is high and the long-term efficacy is not good in long-term follow-up cases. With the widespread use of antineovascular drugs, many authors have explored the use of anti-VEGF drugs alone to treat PCV with good results, especially in the improvement of visual function, and several papers have demonstrated the value of anti-VEGF alone in the treatment of PCV. one-year results of LAPTOP have shown that vitreous cavity injection of ranibizumab is more effective than photodynamic therapy in the treatment of PCV . Despite the significant effect of anti-VEGF in edema elimination and improvement of visual acuity, much of the literature suggests that anti-VEGF therapy is less effective in the elimination of polypoid lesions and abnormal branching vessels. More literature demonstrates that photodynamic therapy in combination with anti-VEGF drugs has better visual acuity improvement and less recurrence rate. Many attempts have been made in China regarding the treatment of PCV, including photodynamic therapy, anti-VEGF alone and combined therapy, but most of them have a small number of cases and more retrospective summary articles. Our advantage is the clinical patient resources, and in order to achieve a leading position in PCV research, we should start to conduct large multicenter studies and draw our own conclusions, instead of being indifferent to others. IV. Prognosis of PCV In 2004, Yanuzzi wrote in his review article that “PCV is a disease with a good prognosis”. Indeed, many patients with PCV, with proper treatment, can recover good visual function, especially if the lesion is small or if it is located outside the central recess. However, as the observation period increases and the number of cases increases, many authors have found that the prognosis of PCV is not as good as expected. Many patients with natural course of the disease eventually lose their visual acuity to less than 0.1. Long-term observations have revealed that PCV treatment has a high recurrence rate, and repeated photodynamic therapy, or the absorption of massive macular hemorrhage, often results in macular atrophy and less than optimal final visual function. Cases of fulminant subchoroidal, subretinal and vitreous cavity hemorrhage due to PCV, which eventually causes secondary glaucoma and thus blindness, have been reported. Therefore, the treatment and prognosis of PCV should never be overly optimistic, and good communication with the patient about the dangers of the disease and the long-term nature of the treatment should be brought to your attention before treatment. PCV has been gradually recognized in China for more than 10 years, and now there has been a great progress in the diagnosis and treatment of PCV, and more articles have been published in basic research, which is a very welcome progress. Our patient population is large and complex, which is a challenge but also an opportunity for us. We hope that we can work together to utilize our case resources and make our original contributions to the research on treatment and disease pathogenesis.