The prevalence of diabetes mellitus in adults of China has reached 12.8%. Diabetic retinopathy (DR) accounts for approximately 1/4-1/3 of the diabetic population. Several millions of people are estimated suffering the advanced stage of DR, including severe non-proliferative DR (NPDR), proliferative DR (PDR) and diabetic macular edema (DME), which seriously threat to the patients’ vision. On the basis of systematic prevention and control of diabetes and its complications, prevention of the moderate and high-risk NPDR from progressing to the advanced stage is the final efforts to avoid diabetic blindness. The implementation of the DR severity scale is helpful to assess the severity, risk factors for its progression, treatment efficacy and prognosis. In the eyes with vision-threatening DR, early application of biotherapy of anti-vascular endothelial growth factor can improve DR with regression of retinal neovascularization, but whether it is possible to induce capillary re-canalization in the non-perfusion area needs more investigation. Laser photocoagulation remains the mainstay treatment for non-center-involved DME and PDR.
Diabetic retinopathy (DR) is the most common complication of diabetes mellitus and has been historically regarded as a retinal microangiopathy. Currently, the diagnosis and classification of DR are still based on vascular abnormalities observed by ophthalmoscopy or color fundus photographs. An increasing number of studies have shown that DR is the result of overall structural and functional disorders of the neurovascular unit, and it is a tissue-specific neurovascular complication. Persistent hyperglycemia in DM not only causes microvascular damage and ischemia, but also leads to retinal inflammation and neuronal degeneration. Furthermore, neurodegeneration often occurs before detectable microvascular lesions. Since 2018, DR has been preferably defined as diabetic retinal disease (DRD), which particularly refers to the effects of diabetes on the entire retina, including neural and vascular components, not only on vascular lesions. The evolution of this term reflects a deepening of the overall understanding of the disease, which helps to promote the improvement of prevention and treatment strategies towards a more systematic and earlier stage. Correspondingly, new challenges have been posed for the assessment, diagnosis, disease staging, and whole disease course management of DRD.
Diabetic retinopathy (DR) is the leading cause of visual impairment worldwide. Severe non-proliferative diabetic retinopathy, diabetic macular edema, and proliferative DR (PDR) are defined as vision-threatening DR (VTDR). In the context of managing systemic disease, the primary treatments for VTDR include panretinal photocoagulation (PRP), intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs or dexamethasone sustained release agents, and microincision vitreous surgery. Although these therapies are already widely used in clinical practice, there is still much debate about the optimal timing and method of their application, especially in the pursuit of optimal efficacy, cost-effectiveness, patient compliance, and the reduction of frequent ongoing treatments. There is no consensus on the best treatment for PDR. Determining the specific criteria for each therapy indication is one of the key considerations. In addition, consideration should be given to the priority between PRP and intravitreal injection, as well as to compare the relative effectiveness of anti-VEGF agents with PRP. Early surgical intervention is not always a necessary option for PDR patients with vitreous hemorrhage and fibrovascular membranes. Combining different therapies to optimize treatment strategies is also an important topic. These issues address several points of contention in best practice guidelines that need to be addressed through more in-depth research to provide better guidance for clinical practice and ultimately improve patient outcomes.
With the tremendous progress in fundus imaging and histopathology over the past decade, the understanding of age-related macular degeneration (AMD) has taken a qualitative leap. AMD is defined as a progressive neurodegenerative disease of photoreceptors and retinal pigment epithelium (RPE) characterized by extracellular deposits under RPE and the retina, including drusen, basal laminar and linear deposits, and subretinal drusenoid deposits, that can evolve to atrophy of the retina, RPE and choroid and neovascularization in the choroid and/or retina. It is the leading cause of blindness and visual impairment in older populations, despite recent advances in treatments. AMD is a multifactorial disease with genetic and environmental factors including advanced age, smoking, high-fat diet, and cardiovascular disorder to enhance the disease susceptibility. The physiopathologic mechanism includes inflammatory processes (complement pathway dysregulation, inflammasome activation), intrinsic (e.g., photo-oxidation) and extrinsic oxidative insult to the retina, age-related metabolic impairment (mitochondrial, autophagic and endoplasmic reticulum stress). Autophagy dysfunction and local inflammation in aged RPE specially result in the extracellular deposits, cell death and AMD. Further investigation of the pathogenesis of AMD will provide with new therapeutic targets and strategy for prevention and treatment of the disease in the early stages.
PURPOSE: Determining the efficacy of vitrectomy in explosive injuries of eye globes and assessing the curcept concept of enucleation for severe traumatized eyes. METIIODS: Clinical records were reviewed on 36 consecutive patients(44 eyes)with severe explosive eyeball injuries. RESULTS:The injuries were caused by explosion of detonator (10 eases), fire-crackers(7 cases) ,explosive and guns(19 cases). Ten eyes(22.7%)were ruptured. Fourty eyes(90. 9%)underwent vitrectomy for posterior segment injuries including vitreous hemorrhage,intraocular foreign bodies, endophthalmitis, and retinal detachment more than 2 weeks after trauma and primary wound repair. Postoperative visual acuity improved in 25 eye(62.5%) ,was stable in 11 eyes(27.5%) ,and decreased in 4 eyes(10%). Final vision was 0. 02 or better (up to 0.7)in 20 eyes(47.6%). No more enucleation was performed except two ruptured eyes (4.5% ) removed in primary clinical units. CONCLUSION :The results suggest that primary wound repair with microsurgery and secondary vitrectomy may reconstruct the eyeball and restore visual functions.at least partially.in the majority of eyes,even though the explosive ocular injuries often induce severe damages and eyeball rupture. It is.thus,recommended that primary enueleation of traumatized eyes should not be performed with an occasional exception. （Chin J Ocul Fundus Dis,1996,12: 169-171）
Purpose To study the effects of Schwann cells(SC) on promoting and supporting axon growth of rabbit retinal neurons in vitro. Methods The scistic nerves of neonatal rabbits were dissected and cultured for 2 weeks to obtain SC monolayers. The retinal cells that had been freshly dispersed were seeded respectively onto the SC monolayers or poly L lysine covered dishes,and the morphology of cultured retinal neurons was observed and the 24th hours and 48th hours respectively under the phase contrast microscopic. Results Retinal neurons of neonatal rabbits attached to the two substrate and extended axons at the 24th hour.Neurite length on SC reached 85plusmn;17mu;m at the 24th hour and 283plusmn;27mu;m at the 48th hour respectively and was significantly longer than on acellular substrate (Plt;0.01) Conciusion SCs are effctive in promoting and supporting neurite growth of retinal neurons in vitro. (Chin J Ocul Fundus Dis,1998,14:212-214)
An experimental model of proliferative vitretinopathy(PVR) induced by macrophages was used for the evaluation of drug efficacy of daunomycin encapsulated in liposomes in the treatment of PVR.Five mu;g daunomycin(n=40),10mu;g daunomycin-liposome(DL,n=30)and 0.1 ml saline or empty liposomes(n=40,as controls)were injected into the rabbit vitreous after macrophage injection.Retinal detachment developed in 77.5% of the control eyes on day 28,compared to 33.3% of the eyes treated with DL(P＜0.01)and 50% of the daunomycin-treated eyes(P＜0.05).The results suggest that encapsulation in liposomes of cytotoxic agents can enhance drug efficacy.The phasic course of development of PVR is important in the selection of particular drugs. （Chin J Ocul Fundus Dis,1993,9:77-80）
Objective:To detect collagen I synthesis activity in the vitreous of PVR induced by macrophages in rabbits. Methods:PC Ⅲ (Procollagen Ⅲ ) concentrations were measured by radioim- munoassay in the vitreous samples of 14 rabbit eyes with experimental PVR and 14 control eyes. Results:The mean PC Ⅲ concentration on the 7th day after macrophage injection as 257.58mu;g/L(range,236.04~266.88mu;g/L,n= 4)and significantly increased on the 14th day later. On the 28th day the mean concentration of PC Ⅲ as 912.23mu;g/L (range, 881.36~943.10mu;g/L ;n= 2). There was a significant difference between the 7th and the 14th, 21st of 28th day statistically(P＜0.05). PC Ⅲ was not detected in control eyes. Conclusion:The PC Ⅲ level in the vitreous of rabbit eyes with experimental PVR increased significantly from the 7th to the 28th day after macrophages injection and is well consistent with the time course of scarring and the development of traction retinal detachment in the PVR model. （Chin J Ocul Fundus Dis,1996,12: 43-44）
Purpose To evaluate the efficacy of vitreous surgery and endolaser in a series of patients with retinal vein occlusion(RVO)with vitreous hemorrhage,neovascular membranes(NVM) and/or traction retinal detachment(TRD). Methods Clinical records were reviewed on 37 consecutive patients(38 eyes)who underwent vitreous surgery and endolaser for RVO with persistent vitreous hemorrhage,NVM and/or TRD.There were 19 patients(20 eyes)with retinal branch vein occlusion (BRVO)and 18 patients(18 eyes)with central retinal vein occlusion(CRVO). Results NVM and TRD were confirmed during operation in 27 and 23 eyes,respectively.Visual acuity improved postoperatively in 34 eyes(89.5%)including 22 eyes with 0.1 or better vision,and 4 eyes remained unchanged.CRVO group had longer history and less visual improvement after surgery. Conclusions Vitreous surgery and endolaser photocoagulation can improve the outcome in the majority of patients with RVO with vitreous hemorrage,NVM and/or TRD. (Chin J Ocul Fundus Dis,1998,14:3-6)
Objective To test the effects of large amount of blood in the vitreous on electrophysiological examination. Methods The reductions of transmission of flash light through a serial dilution and depth of whole blood were measured.An experimental model of vitreous hemorrhage in rabbits was established by injecting 0.5ml autologous uncoagulated whole blood into the vitreous cavities after compression with an expanding perfluoropropane gas bubble.Pars plana vitrectomy was performed to clear the blood clots 2 weeks after blood injection.Ganzfeld and bright-flash electroretinography were performed through six-week observation period. Results Blood reduced remarkably the transmission of reduced remarkably the transmission of bright-flash light.Massive vitreous hemorrhage had a dense filtering effect and extinguished the Ganzfeld but not the bright-flash electrotetinogram.About 3.5log units higher of the intensities of bright- flash light than that of conventional method could stimulate the responses of ERG-B waves in blood injected eyes.Slow recovery of Ganzfeld ERG-b waves after vitrectomy were noted within 2 weeks (Plt;0.05),AND ERG-b wave reached at 80-90% of normal level during the third week. Conclusion The ERG-b waves,which become undetectable because of absorption of the dense opacities of the absorption of the dense opacities of the vitreous in eyes with a large amount of vitreous hemorrhage,can be recorded in bright-flash light conditions with nearly nearly normal amplitudes.This result indicates that functions of retina were not severely damaged by the large amount of vitreous hemorrhage. The injection of large amount of blood into vitreous cavities may cause a transient reduction of the amplitudes of ERG-b waves. (Chin J Ocul Fundus Dis,1998,14:104-107)