The pathogenesis of polypoidal choroidal vasculopathy (PCV) is still controversial. More evidence of clinical and basic research is needed to distinguish PCV from an independent disease to a subtype of age-related macular degeneration. Not only that, there are also many puzzles in the diagnosis, treatment options and prognosis of PCV. In addition to these common problems, we also face a large population with risk factors, a large number of PCV patients with multiple and complex challenges in China. There is a long way to go to reduce the damage effects of PCV on visual function. To fulfil this goal, we need make full use of the huge resources of PCV patients and turn these challenges into opportunities, and contribute the improvement of diagnosis and better understanding of PCV pathogenesis.
The therapeutic effect of anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (nAMD) was determined by a number of factors. Comprehensive thorough analysis of clinical features, imaging results and treatment response can predict the potential efficacy and possible vision recovery for the patient, and also can optimize the treatment regime to make a personalized therapy plan. Precise medicine with data from genomics, proteomics and metabolomics study will provide more objective and accurate biology basis for individual precise treatment. The future research should focus on comprehensive assessment of factors affecting the efficacy of anti-VEGF therapy, to achieve individualized precise diagnosis and treatment, to improve the therapeutic outcome of nAMD.
Diabetic macular edema (DME) is the main cause of visual impairment in diabetic retinopathy patients. It mainly includes focal DME and diffuse DME, while DME of clinical significance needs timely intervention treatment. Optical coherence tomography is currently recognized as the most sensitive method to accurately diagnose DME. Currently, the common treatments of DME include intravitreal injection of anti-vascular endothelial growth factor (VEGF) or glucocorticoid and laser photocoagulation. Among them, anti-VEGF injection is becoming the first-line therapeutic, and corresponding individual treatment or combined treatment strategy should be selected according to the characteristics of DME and the specific conditions of patients. During the diagnosis and treatment of DME, attention should be paid to the systemic treatment of diabetes and the effect of diabetes-related neuroretinopathy on the therapeutic effect of DME. With the appearance of heterogeneity in the efficacy of anti-VEGF drugs, it remains to be further studied how to choose alternative therapeutics and when to replace them.
Most fundus diseases leading to irreversible blindness are associated with genetic variations. Some sequence changes directly cause retinal diseases while others lead to a higher susceptibility to environmental insults common in daily life. Studies of genes related to fundus diseases will lead to a revolutionary change in the prevention and treatment of irreversible blindness. Application of high throughput nextgeneration sequencing and exome capture techniques will greatly enhance our ability to elucidate genes responsible for fundus diseases. With such technical and analytical advances, we are likely to see continuing and accelerating progress in the genetic study of fundus diseases, particularly in those fields requiring collaborative study of common fundus diseases using large cohorts of samples. The translational clinical application of understanding about these newly identified genes responsible for fundus diseases is also increasing in promise. Thus, strengthening current genetic studies of fundus diseases in both of these areas will make a valuable contribution to the prevention and treatment of blindness in both the near and especially the distant future.
The optic nerve belongs to the central nervous system (CNS). Because of the lack of neurotrophic factors in the microenvironment of the CNS and the presence of myelin and glial scar-related inhibitory molecules, and the inherent low renewal potentials of CNS neurons comparing to the peripheral nerve system, it is difficult to spontaneously regenerate the optic nerve after injury. Protecting damaged retinal ganglion cells (RGCs), supplementing neurotrophic factor, antagonizing axon regeneration inhibitory factor, and regulating the inherent regeneration potential of RGCs can effectively promote the regeneration and repair of optic nerve. Basic research has made important progress, including the restoration of visual function, but there are still a lot of unsolved problems in clinical translation of these achievements, so far there is no ideal method of treatment of optic nerve injury. Therefore, it is rather urgent to strengthen the cooperation between basic and clinical research, to promote the transformation of basic research to the clinical applications as soon as possible, which will change the unsatisfactory clinical application status.
Diabetic retinopathy (DR) is the leading causes of blindness in workingaged people, of which diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are the two main causes of visionthreatening. Through the regular screening of patients with diabetes, the risk factors of DR can be identified and proper interventions can prevent the incidence of DR. Timely retinal laser photocoagulation and application of the reninangiotensin system inhibitors (candesartan or fibrates), lipidlowering drug fenofibrate can inhibit DR progress. Macula local and (or) grid pattern photocoagulation or in combination with bevacizumab intravitreal injection can effectively relief DME. In regard to late PDR, vitrectomy could restore or retain useful vision, importantly, minimally invasive 23G vitrectomy and preoperative bevacizumab intravitreal injection greatly improved the surgical outcomes. However DR pathogenesis is not entirely clear. Also there is a lack of effective and feasible DR screening strategy in China. Furthermore existing evidencebased data of medical and surgical treatment of DR is insufficient. Therefore, the DR prevention and treatment is still a long way to go in China.
Myopic choroidal neovascularization (MCNV) is one of the main reasons of vision loss in working population in Asia, which has brought economical and social-psychological burdens with high incidence in China, The precise pathogenesis of MCNV is unclear. Metamorphosia is the main reported symptom in these patients. The lesions were usually with smaller area, less leakage and relatively slow progression. Currently, intravitreal anti-vascular endothelial growth factor agents are now the established standard of care for MCNV, which was a major breakthrough in the treatment of MCNV achieving visual acuity improvement. Since the natural history, clinical features and therapy response of this disease is significant different from that in choroidal neovascularization secondary to age-related macular degeneration, the treatment dosing, frequency, retreatment criteria and the follow-up interval should been considerately. Facing the myopia boom in China, there is a need for the development of a precise definition and a more detailed classification for pathogenic myopia, optimize the outcome assessment and follow-up strategy, which should benefit to the further basically and clinical studies.
Appropriate classification and staging is the basis for the diagnosis and treatment of idiopathic macular hole (IMH). According to the appearance of vitreous and retina determined by optical coherence tomography, IMH can be classified as primary or secondary IMH, and IMH with or without vitreous attachment; Vitreous attachment can be further classified as vitreomacular adhesion or vitreomacular traction. According to the measured horizontal diameter, IMH can be classified as large, middle and small IMH. This new classification system and comprehensive parameters improve the traditional Ⅳ-stage theory, with a better description of the occurrence and development of IMH process. It should be used as the general principal to guide IMH classification, evaluation of surgical indications, selection of operative method, and estimation of surgical outcome. Ganglion cell damage caused by internal limiting membranes (ILM) peeling is the major concern in the IMH vitreoretinal surgery. For complicated and large IMH, inverted ILM flapping can improve the closure rate; ILM peeling and postoperative face-down posture are not necessary for IMH less than 250um in diameter. The current vitreoretinal surgery trend to treat IMH is personalized surgical treatment, following the existing evidence-based medical evidence, and based on the new classification information, ocular and systemic features of each patient.
Evidence-based guidelines for diagnosis and treatment of diabetic retinopathy in China (2022) is based on evidences in recent clinical trials and a system of Grading of Recommendations, Assessment, Development and Evaluation of evidence quality and strength of recommendations. The main key points around why the diabetic macular edema (DME) changes the classification, what thresholds for initiating anti-vascular endothelial growth factor (VEGF) drug therapy; eyes with center-involved DME (CI-DME) and good vision for clinical significant macular edema still treated by focal laser even with good vision, the clinical pathway for CI-DME changes first-line treatment from laser to anti-VEGF, loading dose of anti-VEGF for CI-DME in non-proliferative diabetic retinopathy (DR) from 3 injections up to 4-5 injections is recommended; severe non-proliferative DR and proliferative DR with vision impairment but without hemorrhages and retinal traction could be considered first treatment of anti-VEGF comparing to initiate pan-retinal photocoagulation (PRP) (weakly recommended), PRP is still gold-standard for progressive non-perfusion area of retina. With the rapid development of DR evaluation devices such as optical coherence tomography, wide-angle optical coherence tomography angiography and wide-angle fluorescein fundus angiography, imaging biomarkers have been provided for the degree of DR lesion, treatment response and prognosis. It is believed that the clinical practice will be promoted a new height by the 2022 edition of Chinese DR guideline.
Optical coherence tomography angiography (OCTA) is a new and non-invasive imaging technique that is able to detect blood flow signal in the retina and the choroid within seconds. OCTA is different from the traditional angiography methods. The major advantages of OCTA are that it can observe blood flow signal in different layers of the retina and the choroid without injecting any dye, provide blood flow information that traditional angiography cannot provide, and enrich pathophysiological knowledge of the retinal and choroidal vascular diseases., which help us to make an accurate diagnosis and efficient evaluation of these diseases. However there is a large upgrade potential either on OCTA technique itself or on clinical application of OCTA. We need to fully understand the advantage and disadvantage, and differences of OCTA and traditional angiography. We also need to know how to interpret the result of OCTA. With that we could make a fast diagnosis in a non-invasive way and improve our knowledge of the retinal and choroidal vascular diseases.