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.
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）
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.
Drusen is one of the early hallmark changes of AMD. The oxidative stress and inflammatory reaction caused by oxidative phospholipids (OxPLs) in drusen can lead to retinal pigment epithelium (RPE) cell death (apoptosis, pyroptosis, etc.) and the formation of choroidal neovascularization, which is the pathogenesis of AMD. Pyroptosis, also known as inflammatory necrosis, is one of the main forms of OxPLs induced cell death. Proinflammatory factors released by pyroptic cells can in turn aggravate the inflammatory reaction, leading to further damage. In order to prevent AMD, inflammatory response and cell death may be reduced by regulating lipid metabolism, reducing OxPLs endocytosis and increasing cholesterol efflux. In-depth understanding effects of OxPLs, inflammation and RPE pyrosis in the pathogenesis of AMD in elucidate the pathogenesis of AMD and to seek new treatment measures has important clinical significance.
Purpose To investigate the expression of the interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-alpha;) in epiretinal membranes(ERM) of eyes with proliferative vitreoretinopathy(PVR). Methods Nineteen epiretinal membranes were obtained form eyes undergoing vitrectomy for retinal detachment complicated with PVR and observed by immunohistochemical methods. Results Expression of IL-6 and TNF-alpha; were observed in 12 and 15 membranes respectively with positive staining mostly in extracellular matrix of epiretinal membranes.Only one membrane showed positive to IL-6 intracellularly,and expression for IL-6 and TNF-alpha; simultaneously in membranes. Conclusion The findings indicate that IL-6、and TNF-alpha;might be involved in the development of PVR. (Chin J Ocul Fundus Dis,1998,14:219-221)
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）
We observed 12(35.3%) cases of subretinal membranes in 34 patients with long-standing retinal detachments with proliferative vitreoretinopathy. Transmission electron microscopy revealed that glial cells, retinal pigment epithelial cells and a great amount of collagen represented the basic cellular and substantial components in a subretinal membrane obtained by vitreous surgery. （Chin J Ocul Fundus Dis,1994,10:165-166）
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)
Objective To study the effects of neonatol rabbit Schwann cells(SC) on repair of optic contusion in adult rabbits. Methods 24 h after the adult rabbit optic nerves was contused,0.1 ml of SC suspension (group A) and saline water (group B) were injected into the vitreous of injured eyes respectively.All the animals were studied by retinal ganglion cell (RGC) and axon counting,flash visual evoked potential (FVEP) tests at various intervals after injury. Results At the 4th week after injury,the number of RGC was (19.89plusmn;3.79)/mm in group A and (12.67plusmn;4.12)/mm in group B,and the density of axons was (94.569plusmn;793)/mm2 in group A and (36.085plusmn;285)/mm2 in group B.There was dramatical difference between group A and B (Plt;0.01).The amplitude of FVEP wave of group A increased from 48% to 88% on the 3rd day after injury,and still dept 78% at the 8th week and group A was significantly higher than group B at various intervals (Plt;0.01). Conclusion SC are effective in promoting the repair of optic nerve contusion by increasing the survival rate of RGC,rescuing axons from degeneration,and dramatically promoting the function of the optic nerve. (Chin J Ocul Fundus Dis,2000,16:91-93)