Comparison of OCT and OCTA manifestations among untreated PCV, neovascular AMD, and CSC in Chinese population

AIM: To compare the qualitative and quantitative features among untreated polypoidal choroidal vasculopathy(PCV), neovascular age-related macular degeneration(nv-AMD) and central serous chorioretinopathy(CSC) using optical coherence tomography(OCT) and OCT angiography(OCTA).METHODS: This retrospective study included 16 eyes with thin-choroid PCV, 18 eyes with thick-choroid PCV, 16 eyes with nv-AMD and 17 eyes with CSC, respectively. The indicators were obtained by OCT and OCTA.RESULTS: Sub-foveal choroidal thickness(SFCT) in CSC was thicker compared to other groups(all P<0.05). SFCT in nv-AMD was thicker compared to thin-choroid PCV, but thinner compared with thick-choroid PCV(both P<0.05). As the ratio of thickness of Haller's layer to thickness of SFCT, which of thin-choroid PCV was significantly higher than CSC(P<0.001). Likewise, thick-choroid PCV had significantly higher ratio than nv-AMD(P=0.016) or CSC(P<0.001). There were differences among them in pigment epithelium detachment(PED). The whole-superficial retinal vessel density(RVD), deep RVD and choroidal capillary vessel density(CCVD) in CSC were significantly higher compared to other three groups, respectively(all P<0.05). The whole CCVD in nv-AMD was higher compared to thick-choroid PCV(P=0.032). Cross-sectional local angiographic form was 87.50%, 83.33%, 0 and 35.29% in thin-choroid PCV, thickchoroid PCV, nv-AMD and CSC, respectively. Cross-sectional diffuse angiographic form was 12.50%, 16.67%, 100% and 5.88% in thin-choroid PCV, thick-choroid PCV, nv-AMD and CSC, respectively.CONCLUSION: Combination of OCT and OCTA can effectively observe the significant alterations existed in PCV, CSC and nv-AMD, and there are distinctive differences among them. The pathogenesis is not exactly the same between PCV and nv-AMD, or PCV and CSC.     

眼睑阴虱1例报告及图片样本

本文报道了1例由阴虱引起的耐药性双侧睑结膜炎病例.在参考了一系列裂隙灯和光学显微镜下照片的基础上,我们描述了寄生虫的结构特点.这有助于精确鉴定和准确诊断该病.     

Exploratory study of non-invasive, high-resolution functional macular imaging in subjects with diabetic retinopathy

AIM:To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy(DR).METHODS:Prospective,cross-sectional comparative case-series in which blood flow velocities(BFVs)and noninvasive capillary perfusion maps(nCPMs)in macular vessels were measured in patients with DR and in healthy controls using the Retinal Functional Imager(RFI)device.RESULTS:A total of 27 eyes of 21 subjects were studied[9 eyes nonproliferative diabetic retinopathy(NPDR),9 eyes proliferative diabetic retinopathy(PDR)and 9 controls].All diabetic patients were type 2.All patients with NPDR and 5 eyes with PDR also had diabetic macular edema(DME).The NPDR group included eyes with severe(n=3)and moderate NPDR(n=6),and were symptomatic.A significant decrease in venular BFVs was observed in the macular region of PDR eyes when compared to controls(2.61±0.6 mm/s and 2.92±0.72 mm/s in PDR and controls,respectively,P=0.019)as well as PDR eyes with DME compared to NPDR eyes(2.36±0.51 mm/s and 2.94±1.09 mm/s in PDR with DME and NPDR,respectively,P=0.01).CONCLUSION:The RFI,a non-invasive imaging tool,provides high-resolution functional imaging of the retinal microvasculature and quantitative measurement of BFVs in visually impaired DR patients.The isolated diminish venular BFVs in PDR eyes compared to healthy eyes and PDR eyes with DME in comparison to NPDR eyes may indicate the possibility of more retinal vein compromise than suspected in advanced DR.     

Early visual function outcomes of topography-guided FS-LASIK and SMILE in treatment of myopia and myopic astigmatism

AIM: To compare the quality outcomes of vision at early phase after topography-guided femtosecond laser-assisted in situ keratomileusis(FS-LASIK-CV) and small incision lenticule extraction(SMILE) in treatment of myopia and myopic astigmatism.METHODS: Retrospective comparative analysis of 49 patients that underwent FS-LASIK(n=23) or SMILE(n=26) procedure for myopia and myopic astigmatism between April and September in 2019. Pre-and postoperative uncorrected visual acuity(UCVA), spherical equivalent refraction(SEQ), cylindrical refraction, contrast sensitivity function(CSF), and corneal higher-order aberrations(HOAs) were evaluated. Independent t-test was used for inter-group comparison, while repeated measures ANOVA was used to analyze changes at different time points. RESULTS: In both groups, 100% of the eyes obtained a UCVA of 20/20 or better at 1 wk, 1, and 3 mo postoperatively. At 1 d and 3 mo postoperatively, UCVA was better in FS-LASIKCV group than in SMILE group. At 1 wk postoperatively, SEQ was lower in SMILE group than in FS-LASIK-CV group(P=0.006). At 3 mo postoperatively, the SEQ reached target refraction in both groups. The residual astigmatism was reduced in both groups without intergroup difference(P>0.05). At 3 mo postoperatively, the spherical aberration and coma under 6 mm pupil size were higher than preoperative levels in both groups(P<0.05). However, the increase in the corneal HOAs in the FS-LASIK-CV group was less than the SMILE group(P<0.05). At 3 mo postoperatively, the log CS were better than preoperative levels under scotopic conditions without glare and scotopic conditions with glare in both groups(P<0.05). At 1 and 3 mo postoperatively, under scotopic conditions without glare and scotopic conditions with glare, FS-LASIK-CV group showed more improvement in log CS at two spatial frequencies(12.0 c/d and 18.0 c/d;P<0.05).CONCLUSION: Both FS-LASIK-CV and SMILE demonstrate to be safe, effective, and predictable in treatment of myopia and myopic astigmatism. Early postoperative improvement in UCVA and CSF at high spatial frequency under scotopic conditions were better after FS-LASIK-CV than SMILE.     

Laser therapy versus intravitreal injection of anti-VEGF agents in monotherapy of ROP:a Meta-analysis

AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior retinopathy of prematurity(APROP).METHODS:A systematic literature search was performed in PubMed,Cochrane Library,and Embase for original comparable studies.We included studies that compare laser therapy and intravitreal injections of anti-VEGF agents monotherapy in ROP regardless of languages and publication types.RESULTS:Complication incidence was significantly higher in laser therapy group(OR:0.38;95%CI:0.19-0.75;P=0.005).Spherical equivalent(SE)was higher in laser therapy[weighted mean difference(WMD):2.40,95%CI:0.88-3.93;P=0.002].The time between treatment and retreatment was longer in laser therapy group(WMD:8.45,95%CI:5.35-11.55;P<0.00001).Recurrence incidence(OR:0.97;95%CI:0.45-2.09;P=0.93)and retreatment incidence(OR:1.24;95%CI:0.56-2.73;P=0.59)were similar in two approaches.Subgroup analysis between type-1 ROP and APROP was not significant except SE reported in the included studies(P<0.0001).CONCLUSION:This Meta-analysis outcome indicates anti-VEGF agents are as effective as laser treatment,and safer than laser in type-1 ROP and APROP.The degree of myopia in APROP is higher than type-1 ROP.More randomized controlled trials in large sample size should be conducted in the future.     

圆锥角膜中细胞凋亡及Fas-L蛋白的表达

目的 探讨凋亡与圆锥角膜发病的关系及凋亡相关蛋白Fas-L的表达.方法 对20例圆锥角膜及5例正常角膜用原位末端标记法(TUNEL)检测凋亡,用免疫组织化学SP法检测Fas-L蛋白的表达;透射电镜观察凋亡细胞的形态学变化.结果 TUNEL染色示圆锥角膜组中上皮层、基质层及内皮层中细胞凋亡与正常角膜组比较差异均有统计学意义(P＜0.05);免疫组织化学示圆锥角膜组与正常角膜组基质层间Fas-L表达比较差异有统计学意义(P＜0.05);透射电镜可见圆锥角膜中存在凋亡特征的细胞.结论 圆锥角膜中存在凋亡,Fas-L蛋白的表达存在异常,Fas-FasL系统可能在圆锥角膜细胞凋亡中发挥了重要作用.     

Relationship between intraocular pressure and parameters of obesity in ocular hypertension

AIM:To evaluate the correlation between intraocular pressure(IOP)and various obesity-related health factors in patients with ocular hypertension in Korea.METHODS:A total of 40850 subjects underwent age,sex,body weight,and height assessments and automated multiphasic tests,including non-contact tonometry,automated perimetry,fundus photography,systolic/diastolic blood pressure measurement,and evaluation of obesity-related health parameters such as obesity index,body mass index(BMI),a body shape index(ABSI),and waist-to-height ratio(WtHR).Subjects were divided into ocular hypertension group and normal IOP group according to IOP after matching of age and sex.RESULTS:Of 40850 participants,1515(3.7%)had ocular hypertension,and 1515 with normal IOP were selected as controls using propensity score matching.The mean IOP of control group was 15.3±2.3 mm Hg,compared with 23.3±1.6 mm Hg in ocular hypertension group.Height,obesity index,BMI,and WtHR in the ocular hypertension group were significantly higher than in the normal IOP group(P<0.001,P<0.001,P=0.009,P=0.002).IOP of ocular hypertension was positively correlated with obesity index(P=0.027)and BMI(P=0.016),whereas IOP of control was positively correlated with blood pressure(P<0.001,P=0.002),obesity index(P<0.001),BMI(P<0.001),and WHtR(P=0.002).Systolic blood pressure(β=0.022,P<0.001)and body weight(β=0.016,P=0.02)were precursors of IOP in normal subjects,but sex(male;β=-0.231,P=0.008)and obesity index(β=-0.007,P=0.017)were precursors of ocular hypertension according to multiple regression analysis.CONCLUSION:Among various obesity-related health parameters,obesity index is the best indicator for further increase in IOP in ocular hypertension group.     

Predictors of angle widening after laser iridotomy in Chinese patients with primary angle-closure suspect using ultrasound biomicroscopy

AIM:To assess the predictive value of baseline parameters of ultrasound biomicroscopy(UBM) for angle widening after prophylactic laser peripheral iridotomy(LPI) in patients with primary angle-closure suspect(PACS).METHODS:Angle-opening distance(AOD),trabecular iris angle(TIA),iris thickness,trabecular-ciliary process angle,and trabecular-ciliary process distance were measured using UBM performed before and two weeks after LPI.Iris convexity(IC),iris insertion,angulation,and ciliary body(CB) size and position were graded.Uni-and multivariate regression analyses were used to determine factors predicting the change in AOD(ΔAOD500,calculated as an angle width change before and after LPI) in all quadrants and in subgroup quadrants based on IC.RESULTS:In 94 eyes of 94 patients with PACS,LPI led to angle widening with increases in AOD500 and TIA(P<0.01).Multivariable regression analysis showed that IC(P<0.001),CB position(P=0.007) and iris insertion(P=0.049) were significantly predictive for ΔAOD500.All quadrants were categorized into extreme IC(27.8%),moderate IC(62.3%),and absent IC(9.9%) subgroups.The AOD500 increased by 220% and no other predictive factor was found in the extreme IC quadrants.The AOD500 increased by 55%,and baseline iris angulation was predictive for smaller changes in ΔAOD500 in the moderate IC quadrants.CONCLUSION:In PACS patients,quadrants with greater iris bowing predict substantial angle widening after LPI.Quadrants with a flatter iris,anteriorly positioned CB,and basal iris insertion are associated with less angle widening after LPI.Quadrants with iris angulation as well as a flatter iris configuration predict a smaller angle change after LPI.     

Clinical outcomes of transepithelial photorefractive keratectomy versus femtosecond laser assisted keratomileusis for correction of high myopia in South Egyptian population

AIM: To evaluate the safety and efficacy of transepithelial photorefractive keratectomy(t-PRK) with adjuvant mitomycin C(MMC) versus femtosecond laser assisted keratomileusis(Femto-LASIK) in correction of high myopia.METHODS: Prospective randomized comparative study including 156 eyes of 156 patients with high myopia and a spherical equivalent refraction(SER) <-6.00 D. They were divided randomly into two groups: Group A included 72 eyes treated with t-PRK with adjuvant MMC and Group B included 84 eyes treated with Femto-LASIK. Visual acuity, SER, corneal topography, pachymetry and keratometry were assessed for 12 mo postoperatively.RESULTS: The preoperative mean SER was-8.86±1.81 and-9.25±1.70 D in t-PRK MMC group and Femto-LASIK respectively(P=0.99) which improved to-0.65±0.43 D and-0.69±0.50 D at 12 mo follow up. Mean SER remained stable during the 12 mo of follow-up, with no statistically significant difference between the two groups(P=0.64). In t-PRK MMC group, only six eyes needed retreatment after six months of follow up. And two eyes showed haze(one reversible haze grade 2, while the other had dense irreversible haze grade 4).CONCLUSION: t-PRK MMC provides safe and satisfactory visual outcomes and acceptable risk as Femto-LASIK in patients with high myopia.     

散光视标检查与散光轴位关系的定量推导

目的 定量推导散光视标检查与散光轴位之间的关系.方法 根据光学和数学的原理,从点光源成像入手,逐步定量地推导被检者对散光视标的辨认结果和散光轴位之间的关系.结果 被检者看到的最清晰散光视标的时钟钟点数乘以30°,即为被检者的散光轴位.或者被检者看到的最不清晰的散光视标的时钟钟点数加上3乘以30°,亦为被检者的散光轴位.结论 被检者对散光视标辨认结果和散光轴位之间关系的定量推导有助于正确的理解和临床应用.     

斜视对心理的影响

斜视不但影响患者的视功能、容貌,对患者的心理影响也是明显的.主要表现在斜视患者普遍存在抑郁、低自尊、社交焦虑和就业方面.另外,斜视患儿父母也因其孩子的影响而存在抑郁、紧张、焦虑.对年幼患儿斜视手术可以有效地改变他们的视功能,提高其适应社会的能力.对青少年和成年人斜视手术可改善其容貌,提高自尊水平,减少受到的社会歧视,减轻社交焦虑,更好的获得就业.     

近视管理白皮书（2019）

近50 年来，近视的发病率急剧增加[1]，儿童过早地发生近视以及错误的治疗会造成近视快速发展，不但导致屈光度增加，更有可能导致严重的眼部并发症[2，3]。近视管理白皮书是在教育部等8 部门发布的《综合防控儿童青少年近视实施方案》基本框架下，面向全国视光工作者以及近视患者，特别是儿童青少年，制定出可信、可行、可及的近视管理规范方案。本共识是在对国家策略和实施方案等有关精神充分研究和认知的基础上，结合最新近视科学研究和我国近视发病特征提出的，旨在保障近视管理工作的规范化、科学化开展，规范近视管理工作有序进行。     

Elevated VEGF-A & PLGF concentration in aqueous humor of patients with uveal melanoma following Iodine-125 plaque radiotherapy

AIM: To measure the concentration of vascular endothelial growth factor-A(VEGF-A), and placental growth factor(PLGF) in aqueous humor of uveal melanoma patients before and after Iodine-125 plaque therapy(IPT), determine the postoperative fluctuation and evaluate associated factors in vivo.METHODS: Participants were 18 Chinese patients with uveal melanoma who were elected to IPT. Undiluted aqueous humor samples were collected at Iodine plaque implant and removal time, then stored immediately at-80℃ until assayed. The concentration of VEGF-A, PLGF and other 7 cytokines comprising interleukin-2(IL-2), IL-8, IL-10, interferon(IFN)-γ, programmed death(PD)-1, transforming growth factor(TGF)-β1 and insulin-like growth factor(IGF)-1 in aqueous humor was measured using Raybiotech immunoassay kit, a high throughput strategy. The VEGF-A and PLGF levels were compared across preoperation and postoperation subgroups, as well as those of other 7 interleukins. Correlation and grouped analyses were conducted to determine the independent effects of clinical parameters and other cytokines on VEGF-A and PLGF concentration or fluctuation. This study set a self-control design.RESULTS: VEGF-A(P=0.038) and PLGF(P=0.026) were the only two increased cytokines after IPT. Preoperative and postoperative level of VEGF-A and PLGF(r=0.575, P=0.013;r=0.987, P<0.001) correlated with each other significantly. Level of VEGF-A(r=0.626, P=0.005;r=0.588, P=0.01) and PLGF(r=0.616, P=0.007;r=0.588, P=0.01) had positive correlation with tumor thickness consistently. Elevated VEGF-A or PLGF level were strong predictive factors of each other(P=0.007, OR=60.0). The elevated VEGF-A group showed a higher postoperative level of IFN-γ(P=0.005), IL-2(P<0.001) and IL-10(P=0.004) in aqueous humor. When the elevated PLGF group got similar results that a higher postoperative level of IFN-γ(P=0.007), IL-2(P<0.001) and IL-10(P=0.013) in aqueous humor. CONCLUSION: This study reveals that VEGF-A and PLGF in aqueous humor significantly increased with tumor thickness and radiation process in uveal melanoma patients. VEGF-A and PLGF may be crucial in uveal melanoma genesis and radiotherapy reactions. Immune mediators comprised IFN-γ, IL-2 and IL-10 could play roles in the link between inflammation and angiogenesis in uveal melanoma when exposed to radiotherapy.     

Intracameral anti-VEGF injection for advanced neovascular glaucoma after vitrectomy with silicone oil tamponade

AIM: To evaluate the effect of intracameral injection of conbercept for the treatment of advanced neovascular glaucoma(NVG) after vitrectomy with silicone oil tamponade.METHODS: Conbercept 0.5 mg/0.05 m L was injected into the anterior chamber of 5 eyes, which had developed advanced NVG after vitrectomy with silicone oil tamponade. Then, trabeculectomy with mitomycin C and pan-retinal photocoagulation(PRP) or extra-PRP were conducted within 2 d. The follow-up time was 6 mo. Best-corrected visual acuity(BCVA), intraocular pressure(IOP), neovascularization of iris(NVI) were recorded before and after treatment.RESULTS: Within 2 d after injection, IOP control, and NVI regression were optimal for trabeculectomy. Hyphema occurred in one eye in the process of injection. But none of them present hyphema after trabeculectomy. At the end of follow-up time, all eyes had improved BCVA, well-controlled IOP, and completely regressed NVI. CONCLUSION: Intracameral injection of conbercept is safe and effective in the treatment of patients with advanced NVG after vitrectomy with silicone oil tamponade. Within 2 d after injection is the optimal time window for trabeculectomy, which can maximally reduce the risk of perioperative hyphema.     

Impact of systemic steroids combined with immunosuppressive treatment on glaucomatous features in patients with systemic lupus erythematosus

AIM:To evaluate the incidence of increased intraocular pressure(IOP)and glaucomatous changes in systemic lupus erythematosus(SLE)patients in comparison with systemic steroids and immunosuppressive treatment.METHODS:Sixty-two women with SLE were divided into two groups:treated(n=47,94 eyes)and not treated(n=15,30 eyes)with systemic glucocorticosteroids(GC;GC-free).Twenty-one individuals in GC group were treated with immunosuppressive agents(immunomodulating and biologic).The visual acuity and IOP with ocular pulsatile amplitude(OPA)measurements,as well as scanning laser polarimetry(GDx)with nerve fiber index(NFI)measurement,spectral domain optical coherence tomography(SD-OCT)of the optic disk with retinal nerve fiber layer(RNFL)analysis and the macular region with ganglion cell analysis(GCA)were performed.RESULTS:Mean IOP values in group with combined GC and immunosuppressive therapy was 15.8±2.56 mm Hg and was significantly lower than in individuals with exclusive GC treatment(17.63±4.38 mm Hg,P=0.043).Contrary,no dif ferences in mean IOP values between GC-free group and individuals treated with combined GC and immunosuppressive therapy were detected(P=0.563).Similarly,mean IOP in GC was 17.14±3.94 mm Hg and in GC-free patients was equal to 16.67±3.45 mm Hg(P=0.671).According to treatment regimen no statistical differences in optic disk SD-OCT for RNFL thickness,RNFL symmetry,cupping volume and the C/D ratio were observed.Similarly,no statistical differences for the mean and minimal ganglion cell layer(GCL)thickness measured in macular SD-OCT or NFI in GDx were detected.CONCLUSION:Combined immunosuppressive and systemic GC therapy in SLE patients may lower the risk of iatrogenic ocular hypertension.No relationship between treatment regimen and glaucomatous damage of optic nerve fibers in analyzed groups with SLE is detected.     

Analysis of the etiologies, treatments and prognoses in children and adolescent vitreous hemorrhage

AIM:To determine the etiologies,treatment modalities and visual outcomes of vitreous hemorrhage(VH;range from birth to 18 y).METHODS:A total of 262 eyes from 210 patients between January 2010 and September 2016 were included.All children underwent an appropriate ocular and systemic examination.Data collected included demographics,clinical manifestations,details of the ocular and systemic examination,management details,final fundus anatomy and visual acuity(VA).RESULTS:The most common etiologies were nontraumatic VH(64.89%),most of which were due to retinopathy of prematurity(ROP;37.10%);while traffic accidents,including 16(21.00%)eyes,was the most common ocular traumas.Surgery,performed in 143(54.58%)eyes,was the most common management modality.The initial mean baseline visual acuity was 2.77±0.21 logarithm of the minimal angle of resolution(log MAR)in children and adolescent with traumatic VH,which was significantly improved to 2.15±1.31 log MAR(P<0.05).CONCLUSION:VH in children and adolescent has a complicated and diverse etiology.ROP is the primary cause of non-traumatic VH,which is the most common etiology.Appropriate treatment of traumatic VH is associated with obvious improvement in visual acuity.The initial VA is one of most important predictors of outcome.     

Molecular pathobiology of scleritis and its therapeutic implications

Scleritis and other autoimmune diseases are characterized by an imbalance in the levels of pro-inflammatory and anti-inflammatory molecules with the balance tilted more towards the former due to the failure of recognition of self. The triggering of inflammatory process could be ascribed to the presence of cytoplasmic DNA/chromatin that leads to activation of cytosolic DNA-sensing c GAS-STING(cyclic GMP-AMP synthase linked to stimulator of interferon genes) pathway and enhanced expression of NF-κB that results in an increase in the production of pro-inflammatory bioactive lipids. Bioactive lipids gamma-linolenic acid(GLA), dihomoGLA(DGLA), prostaglandin E1(PGE1), prostacyclin(PGI2) and lipoxin A4, resolvins, protectins and maresins have antiinflammatory actions, bind to DNA to render it non-antigenic and are decreased in autoimmune diseases. These results suggest that efforts designed to enhance the production of anti-inflammatory bioactive lipids may form a new approach to autoimmune diseases. Local injection or infusion of lipoxins, resolvins, protectins and maresins or their precursors such as arachidonic acid may be exploited in the prevention and management of autoimmune diseases including scleritis, uveitis and lupus/rheumatoid arthritis.     

Corneal epithelial thickness analysis of forme fruste keratoconus with optical coherence tomography

AIM:To explore the significance of corneal epithelial thickness analysis in diagnosing early keratoconus.METHODS:There were 26 clinical keratoconus,21 forme fruste keratoconus,40 high corneal astigmatism(ΔK)and 40 low ΔK eyes involved in the study.Fourierdomain optical coherence tomography was used to measure the corneal epithelial thickness of four groups.The morphological features of topographic map and the thickness of corneal epithelial thinnest point were analyzed.The distribution curve of corneal epithelial thickness at 45°,90°,and 135° axial directions that are through the pupil center was also analyzed.One-way ANOVA was performed to compare the data.RESULTS:The topographic map of forme fruste keratoconus corneal epithelial thickness was uniformity shape;crater shape existed only in clinical keratoconus group;and central island shape mainly existed in highΔK group.The thinnest point of corneal epithelial thickness of forme fruste keratoconus group was significantly lower than that of low ΔK group(P=0.022).The thickness of corneal epithelium in the forme fruste keratoconus at 90°was thinner than that in the low astigmatism group at -1,and -2 mm points(P_-1mm=0.015,P_-2mm=0.036).CONCLUSION:The analysis of the thinnest point in forme fruste keratoconus corneal epithelium appears earlier than corneal epithelial remodeling.The topographic map of corneal epithelium in high ΔK eyes appears in central island shape,and can be used for the differential diagnosis of early keratoconus.     

老视手术治疗进展

随着人们对视觉质量要求的提高,不损伤远视力的前提下恢复近视力是目前老视矫正手术所追求的目标.为了达到此目的,出现了多种手术方法.本文就近年来国内外报道的有关角膜、晶状体及巩膜等的老视矫正术作一综述.     

LASIK术中负压吸引对兔视网膜组织氧自由基的影响

目的 观察LASIK术中负压吸引对新西兰兔视网膜组织氧自由基的影响.方法 用LASIK负压吸引装置持续吸引新西兰免右眼30 s、60 s、300 s或间断吸引30 s 2次,左眼为对照,于1 h、1 d、7 d后测定视网膜组织中超氧化物歧化酶(superoxide dis-mutase,SOD)、过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathion peroxidase,GRH-px)活性及丙二醛(malondialdehyde,MDA)含量,并观察视网膜组织在电镜下的形态学改变.结果 酶学及MDA检测:负压吸引30 s组SOD、CAT和GRH-px各酶活性稍有降低,MDA生成量也有所增加,但第7天时接近正常水平[第7天时4项指标在视网膜组织蛋白中含量分别为(162.49±17.39)nU·mg-1、(2.25±0.73)nmol·mg-1、(5.37 ±1.00)U·mg-1、(2.40 ±0.67)U·mg-1)].负压吸引60 s组与之相比,酶活性降低以及MDA生成增加更为明显,持续时间也较长[第7天时4项指标在视网膜组织蛋白中含量分别为(149.64±13.51)nU·mg-1、(2.64±0.71)mmol·mg-1、(3.3l±0.51)u·mg-1、(1.82±0.91)u·mg-1].间断负压吸引30 s2次组的结果则介于前二者之间[第7天时4项指标在视网膜组织蛋白中含量分别为(157.16±11.95)nU·mg-1、(3.84士1.13)nmol·mg-1.、(3.69±1.61)U·mg-1、(3.08±0.50)u·mg-1].而负压吸引300 s组与以上3组相比,酶活性降低及MDA生成增加最为显著,持续时间最长,且第7天时实验组与相应对照组之间差异比第1天更为显著[第7天时4项指标在视网膜组织蛋白中含量分别为(140.01±14.32)nU·mg-1、(2.40±0.89)nmol·mg-1、(3.65±0.79)U·mg-1、(2.01±0.48)U·mg-1].组织形态学变化:各实验组视网膜组织结构改变均比较轻,只可见视细胞内节线粒体轻度肿胀变性,内核层细胞核周间隙增宽,内质网轻度扩张等改变.结论 负压吸引的确引起视网膜组织内氧自由基增加并诱发视网膜组织结构的轻微变化.