Professor Feng Kang: Drive innovative research with innovative technologies to gain insight into the "truth" of PCV

Editor's Note For a long time, the etiological research on polypoidal choroidal vasculopathy (PCV) has been in the ascendant, and it has become a hot spot in the international ophthalmology field, which has important guiding significance for the selection of its treatment methods. The development of vitreoretinal surgery technology has also helped PCV to obtain more treatment options to a certain extent, and played an important role in the exploration of its etiology. Recently, the team of Professor Ma Zhizhong and Professor Feng Kang of Peking University Third Hospital combined a variety of treatment methods for PCV, and analyzed the etiology of PCV through innovative research and put forward novel views. The results of this research were presented to fellow ophthalmologists at the Ophthalmic Surgery Technology Symposium. Therefore, we specially invited Professor Feng to introduce the research and describe in detail the PCV surgical experience of the more advanced 10K/27G minimally invasive high-speed vitrectomy system used in the research for vitreoretinal surgery. Focus on international research hotspots and in-depth exploration of the etiology of PCV PCV is a type of macular disease that occurs in people of color [1]. Since the 1990s, the etiology of PCV has become the focus of international ophthalmology. The disclosure of the "truth" of PCV etiology is crucial to the choice of treatment. Because PCV patients have lower intraocular VEGF concentrations than typical AMD, anti-VEGF therapy is less effective and has a lower polyp regression rate [2], and anti-VEGF combined with verteporfin photodynamic therapy (vPDT) is currently not more effective. progress. Local thermal laser photocoagulation also has disadvantages such as scarring, RPE tear, recurrence of polyp lesions, and secondary CNV. Therefore, the treatment of PCV is a major difficulty faced by clinicians. Recently, Professor Ma Zhizhong and Professor Feng Kang of Peking University Third Hospital led the fundus surgery team to make some new progress in the etiology of PCV through an innovative clinical study. Professor Feng pointed out that this real-world study on PCV treatment and long-term prognosis initiated by the team is one of the few relevant studies in the world. The team is currently collecting medical records, and most of the included samples are PCV patients with severe subretinal hemorrhage combined with vitreous hemorrhage. The study used a combination of various treatment methods for PCV, including transscleral photocoagulation/condensation, intraocular anti-VEGF injection, vitrectomy (10K/27G and 5K/23G) combined with RPE transplantation, etc. Cases were followed up for a long time, and a prospective cohort study of PCV treatment and prognosis was constructed. In addition, the innovation of this study is that after all cases were treated with vitreoretinal surgery, the subretinal polypoid lesions (Polyps) tissue removed during the operation were observed by electron microscopy, and histopathology, cytology, molecular A series of studies such as biology, and genetics are expected to further explore the pathogenesis of PCV. In the past, the mainstream view of international ophthalmology believed that the etiology of PCV mainly originated from the choroid, and choroidal hypertrophy, choroidal vascular malformation, and choroidal vascular return blockage were the "initiating factors" leading to the pathogenesis of PCV, which in turn led to the formation of subretinal neovascularization [3] . However, in this study, the team of Professor Ma Zhizhong and Professor Feng, through in-depth exploration of the subretinal Polyps lesion specimens, believed that Bruch's membrane was the "initiator" of PCV pathogenesis. The mainstream cognition of etiology brings new understanding and enlightenment to the histopathology of PCV. The 10K/27G minimally invasive high-speed vitrectomy system has shown unprecedented breakthroughs and advantages in PCV vitreoretinal surgery. The degree of fundus lesions in PCV patients varies greatly from mild to severe. For early PCV, intraocular injections, lasers, etc. can be used for treatment. However, for PCV patients with severe subretinal hemorrhage or even intravitreal hemorrhage, vitreoretinal surgery is usually required to excise the intravitreal hemorrhage, and the retinal tissue is dissected to clear the subretinal hemorrhage and the primary subretinal PCV lesion. Combined with RPE transplantation, this is also one of the characteristics of the research conducted by the team. In the study, the more advanced 10K/27G vitrectomy head was used in vitreoretinal surgery. Clinical observation found that it has the following advantages: more minimally invasive and faster. First of all, in the international ophthalmology field, the overall development trend of vitreoretinal surgery tends to be Less invasive and faster. For PCV patients with more severe subretinal hemorrhage and vitreous hemorrhage, the risk of damage to normal tissue in the eye during surgical procedures is higher, and more minimally invasive surgical intervention is required. The 27G vitrectomy head complies with the needs of modern vitreoretinal surgery and provides a more minimally invasive incision. In addition, the 10K high-speed vitrectomy head helps to clear the subretinal hemorrhage, reduces the chance of accidental injury to the retina and normal RPE tissue, improves the success rate of the operation, and reduces the occurrence of intraoperative complications. Bevel design, safe and efficient 10K/27G vitrectomy head The bevel design can make it close to the retina for operation, effectively avoiding damage to the fragile RPE tissue and even choroidal tissue, improving the surgical efficiency of clearing subretinal hemorrhage and reducing intraocular re-injury , all provide very good conditions. Transcending the past, transforming and upgrading from 20G, 25G vitrectomy head to 27G vitrectomy head, reflects a very big development transition of vitrectomy surgical equipment. In the past, a 20G vitrectomy head was used, and photocoagulation should be performed on the retinal tissue around the puncture at the end of the operation to avoid postoperative complications. Now the more minimally invasive 27G vitrectomy head is used, which can effectively avoid possible retinal complications. In terms of cutting speed, the previous 5K vitrectomy head may damage normal retinal tissue, RPE tissue, and even choroidal tissue during vitreoretinal surgery. The 10K vitrectomy head, with its higher cutting speed and unique bevel design, can more effectively avoid possible iatrogenic complications. Looking forward to the future, innovative changes in vitrectomy equipment and technology will boost vitreoretinal surgery to a higher level. Professor Feng lamented that the development of clinical medicine, especially the development of ophthalmology, has a strong dependence on the development of overall industrial technology. . In the past two decades, with the rapid development of various ophthalmic examination equipment, surgical instruments and vitreoretinal surgery techniques, people have a deeper understanding of fundus diseases, and the level of diagnosis and treatment has also made great progress. Nowadays, the more advanced 10K/27G vitrectomy head has been greatly improved compared with the previous vitrectomy equipment, which has greatly improved the technique of vitreoretinal surgery. In the future, with the further development of industrial technology, vitrectomy surgery will move towards a higher speed and less invasive direction, which is bound to further improve the vitreoretinal surgery technology and bring more benefits to PCV patients! The above sharing is only the speaker's personal opinion and does not represent Alcon's opinion/position. References: 1. Fenner BJ, Cheung CMG, Sim SS, Lee WK, Staurenghi G, Lai TYY, Ruamviboonsuk P, Kokame G, Yanagi Y, Teo KYC. Evolving treatment paradigms for PCV. Eye (Lond). 2022 Feb;36 (2):257-265. doi: 10.1038/s41433-021-01688-7. Epub 2021 Jul 14. PMID: 34262165; PMCID: PMC8807588.2. Mettu PS, Allingham MJ, Cousins ​​SW. Incomplete response to Anti-VEGF therapy in neovascular AMD: Exploring disease mechanisms and therapeutic opportunities. Prog Retin Eye Res. 2021 May;82:100906. doi: 10.1016/j.preteyeres.2020.100906. Epub 2020 Oct 3. PMID: 33022379.3.Cheung CMG, Lai TYY, Ruamviboonsuk P, Chen SJ, Chen Y, Freund KB, Gomi F, Koh AH, Lee WK, Wong TY. Polypoidal Choroidal Vasculopathy: Definition, Pathogenesis, Diagnosis, and Management. Ophthalmology. 2018 May;125(5):708-724. doi: 10.1016/j.ophtha.2017.11.019. Epub 2018 Jan 10. PMID: 29331556.CN-AUV-2200039