糖尿病视网膜病变患者血清同型半胱氨酸、维生素B12及叶酸与氧化应激的关系

目的　分析糖尿病视网膜病变（diabetic retinopathy,DR）患者血清中同型半胱氨酸（homocysteine,Hcy）、维生素B12（vitamin B12,VitB12）、叶酸与氧化应激水平的变化,并探讨它们之间的关系。方法　选取我院2型糖尿病（type 2 diabetes,T2DM）患者140例,所有患者均行眼底镜检查、眼底荧光素血管造影及眼底照相检查,并根据中华医学会眼底病学组诊断及分期标准,将其分为无糖尿病视网膜病变（non-diabetic retinopathy,NDR）患者75例（NDR组）,非增生型糖尿病视网膜病变（non-proliferative diabetic retinopathy,NPDR）患者37例（NPDR组）,增生型糖尿病视网膜病变（proliferative diabetic retinopathy,PDR）患者28例（PDR组）。另选取我院体检中心体检合格,无血糖及糖化血红蛋白异常者70例为正常对照组。分别检测每组患者血清Hcy、VitB12、叶酸、超氧化物歧化酶（superoxide dismutase,SOD）、丙二醛（malondialdehyde,MDA）、还原型谷胱甘肽（reduced glutathione,GSH）水平。并将NPDR组患者随机分为A组18例、B组19例,A组给予口服胰激肽原酶肠溶片,B组给予VitB12+口服叶酸加胰激肽原酶肠溶片,分别治疗1个月后检测两组患者血清Hcy、VitB12、叶酸、SOD、MDA、GSH水平。结果　NDP组、NPDR组、PDR组与正常对照组血清Hcy和MDA含量总体比较差异均有统计学意义（均为P=0.000）,其中NDR 组、NPDR 组、PDR 组Hcy、MDA水平均依次增高,且均明显高于正常对照组（均为P＜0.05）;NDP组、NPDR组、PDR组与正常对照组血清VitB12、叶酸、SOD、GSH含量总体比较差异均有统计学意义（均为P=0.000）。其中NDR组、NPDR组、PDR组VitB12、叶酸、SOD、GSH水平均依次降低,且均明显低于正常对照组（均为P＜0.05）。治疗1个月后,A组患者血清Hcy、MDA、VitB12、叶酸、SOD、GSH含量较治疗前均无明显变化（均为P>0.05）;B组患者血清Hcy、MDA较治疗前均显著降低（均为P＜0.05）,血清VitB12、叶酸、SOD、GSH含量较治疗前均显著升高（均为P＜0.05）,且B组治疗后血清Hcy、MDA含量均明显低于A组（均为P＜0.05）,VitB12、叶酸、SOD、GSH含量均明显高于A组（均为P＜0.05）。血清Hcy与 MDA水平呈正相关（r=0.79,P＜0.05）,与VitB12、叶酸、SOD、GSH 水平均呈负相关（r=-0.61、-0.54、-0.43、-0.57,均为 P＜0.05）。结论　DR患者血清VitB12、叶酸水平降低,同时伴随Hcy水平升高,氧化应激反应增强。联合应用VitB12、叶酸治疗有助于降低DR患者血清Hcy水平及氧化应激反应。     

2型糖尿病并发视网膜病变患者血清缺血修饰白蛋白和超敏C-反应蛋白浓度的变化

目的 探讨2型糖尿病并发视网膜病变(DR)患者血清缺血修饰白蛋白(IMA)和超敏C-反应蛋白(hs-CRP)浓度的变化.方法 病例对照研究.采用酶联免疫吸附测定法和速率散射比浊法检测79例DR组患者血清IMA和hs-CRP浓度变化,并与83例非DR(NDR)糖尿病组患者和72例对照组受检者进行比较,同时将40例增殖性DR(PDR)组患者与39例非增殖性DR(NPDR)组患者进行比较.采用PPMS 1.5统计学软件进行数据分析.两组均数比较采用t检验;多组均数比较采用单因素三水平设计定量资料方差分析,多个均数之间两两比较采用q检验.结果 DR组患者血清IMA浓度(46.51±13.29)μg/L,hs-CRP浓度(4.27±2.24)mg/L;NDR组患者血清IMA浓度(25.47±9.33)μg/L,hs-CRP浓度(2.96±1.84)mg/L;对照组血清IMA浓度(15.36±4.27)μg/L,hs-CRP浓度(1.86±0.97)mg/L;PDR组患者血清IMA浓度(54.72±15.61)μg/L,hs-CRP浓度(6.34±3.53)mg/L;NPDR组患者血清IMA浓度(38.35±11.27)μg/L,hs-CRP浓度(3.28±1.77)mg/L.DR组患者血清IMA和hs-CRP浓度明显高于对照组和NDR组,NDR组患者血清IMA和hs-CRP浓度高于对照组,差异有统计学意义(F=197.124,34.561;q=5.41～27.34;P<0.01);PDR组患者血清IMA和hs-CRP浓度明显高于NPDR患者组,差异有统计学意义(t=5.46,4.89;P<0.01);DR组患者血清IMA与hs-CRP浓度呈正相关(r=0.617,P<0.01).结论 DR患者血清IMA和hs-CRP浓度明显升高,且与病情严重程度呈正相关,可能影响DR的发展.     

糖尿病视网膜病变患者血清S100A8/A9变化与视网膜炎症反应的关系

背景 炎症-免疫机制是目前糖尿病视网膜病变(DR)机制研究的热点之一,研究表明,S100A8/A9蛋白复合物与炎症相关,但S100A8/A9蛋白是否参与DR的发生和发展有待探讨. 目的 测定糖尿病(DM)及DR患者血清S100A8/A9蛋白质量浓度,探讨其在疾病发生和发展中的作用. 方法 采用病例对照研究设计,选取2014年1-6月在上海市徐汇区中心医院诊治的DR患者(DR组)和无视网膜病变的2型DM患者(DM组)30例,以及健康体检者(正常对照组)30人,依据DR的病变程度将DR组亚分为非增生性DR (NPDR)组和增生性DR (PDR)组.采集受检者空腹静脉血并分离血清,采用ELISA法测定受检者血清S100A8/A9蛋白质量浓度,分别采用免疫透射比浊法和免疫凝集法测定受检者血清超敏C反应蛋白(hsCRP)质量浓度和糖化血红蛋白(HbAlc)含量.结果 DR组、DM组和正常对照组受检者血清S100A8/A9质量浓度分别为(9.74±0.59)、(11.41±0.64)和(6.46±0.62) μg/L,其中DM组和DR组患者血清S100A8/A9质量浓度均明显高于正常对照组,DM组患者血清S100A8/A9质量浓度明显高于DR组,差异具有统计学意义(均P=0.00);DR组、DM组和正常对照组受检者血清hsCRP质量浓度分别为(1.40±0.34)、(1.27±0.13)和(1.11±0.12) mg/L,其中DR组、DM组患者血清hsCRP质量浓度均明显高于正常对照组,差异均有统计学意义(均P=0.00);DR组和DM组患者血清HbAlc含量明显高于正常对照组,差异均有统计学意义(均P=0.00),而DR组与DM组差异无统计学意义(P=0.12).NPDR组与PDR组间患者血清S100A8/A9和hsCRP质量浓度及血清HbAlc含量的差异均无统计学差异(t=-0.10,P=0.92;t=-0.17,P=0.87;t=0.66,P=0.51).血清S100A8/A9蛋白质量浓度与血清hsCRP质量浓度间呈弱正相关(r=0.36,P=0.00). 结论 S100A8/A9蛋白是炎症标志物分子之一,可能参与DM相关微血管病变的发生及发展,控制血糖浓度能够减缓DM患者的炎症反应.     

2型糖尿病并发视网膜病变患者血清脂联素和超敏C-反应蛋白浓度的变化

目的:探讨2型糖尿病并发视网膜病变(diabetic retinopathy,DR)患者血清脂联素和超敏C-反应蛋白(high sensitivity C-reactive protein,hs-CRP)浓度的变化。方法:病例对照研究。采用酶联免疫吸附法和速率散射比浊法检测49例非糖尿病视网膜病变(NDR)的糖尿病患者,46例非增生性糖尿病视网膜病变(NPDR)组患者,41例增生性糖尿病视网膜病变(PDR)组患者以及45例对照组受检者血清脂联素和超敏C-反应蛋白(hs-CRP)浓度的变化,采用单因素设计的定量资料的方差分析,多个均数之间两两比较采用q检验,相关分析采用直线相关分析。结果:NDR组患者血清脂联素浓度8.76±3.61mg/L,hs-CRP浓度3.12±1.24mg/L;NPDR组患者血清脂联素浓度6.22±2.53mg/L,hs-CRP浓度4.89±1.66mg/L;PDR组患者血清脂联素浓度3.98±1.86mg/L,hs-CRP浓度6.95±2.59mg/L;对照组血清脂联素浓度13.55±5.87mg/L,hs-CRP浓度2.01±0.85mg/L。正常对照组与NDR组、NDR组与NPDR组、NPDR组与PDR组的血清脂联素比较,差异有统计学意义(q=5.4401,P=0.000;q=3.1535,P=0.002;q=4.8756,P=0.000)。正常对照组与NDR组、NDR组与NPDR组、NPDR组与PDR组血清hs-CRP浓度比较,差异具有统计学意义(q=2.4367,P=0.0017;q=2.0572,P=0.003;q=2.6184,P=0.001)。DR患者血清hs-CRP与血清脂联素水平呈负相关(r=-0.643,P<0.01)。结论:DR患者血清脂联素浓度水平与血清hs-CRP浓度水平存在显著负相关,血清脂联素浓度水平下降,伴随着血清hs-CRP浓度水平的升高,且与糖尿病视网膜病变的严重程度相关。     

血清中VEGF和bFGF水平与糖尿病视网膜病变关系的临床研究

目的:探讨糖尿病视网膜病变患者血清中血管内皮细胞生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)水平与糖尿病视网膜病变的关系。方法:收集患有糖尿病视网膜病变白内障患者的血清样本,并以无糖尿病白内障患者的血清样本作为对照,用ELISA方法测定血清中bFGF,VEGF的含量。结果:对照组12例血清样本bFGF含量为(34.95±9.62)ng/L,VEGF含量为(150±20)μg/L;单纯型DR组中10例bFGF含量为(52.6±7.54)ng/L,VEGF含量为(330±50)μg/L;增生型DR组7例bFGF含量为(64.929±11.917)ng/L,VEGF含量为(580±50)μg/L。和对照组相比糖尿病患者血清中bFGF,VEGF的含量均显著增加(P<0.01),并且随着DR病情的进展而增高(P<0.05);血清中VEGF与bFGF之间呈正相关(r=0.419,P<0.01)。结论:VEGF,bFGF参与了DR的发生发展,并与DR后期新生血管形成关系密切。     

原发性闭角型青光眼血浆同型半胱氨酸水平及其代谢相关指标的检测分析

目的：：探讨同型半胱氨酸水平及其代谢相关指标与原发性闭角型青光眼的关系。方法：选取150例经压平眼压计、Humphrey 视野计( HVF)、光学相干断层扫描( optical coherence tomography, OCT)、房角镜等检查确诊为原发性闭角型青光眼( primary angle-closure glaucoma,PACG)的患者作为试验组和同期150例我院体检中心健康者为正常对照组,抽取空腹外周静脉血,而后测定血浆中同型半胱氨酸( homocysteine, Hcy)浓度、维生素B12及叶酸的浓度,并提取DNA,检测Hcy代谢途径中关键酶———亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR) C677T 的基因型及基因多态性。结果：试验组血浆中Hcy的浓度为16.11±1.66μmol/L,正常对照组为15.74±1.52μmol/L,两组比较,差异有统计学意义(t=2.04,P=0.04)。试验组血浆中维生素B12的浓度为248.09±119.07pg/mL,正常对照组为230.21±142.93pg/mL,两组比较差异无统计学意义( t=0.84,P=0.40)。试验组血浆中叶酸的浓度为12.02±7.81ng/mL,正常对照组为13.15±6.25ng/mL,两组比较差异无统计学意义( t=1.65, P=0.17)。试验组MTHFR C677 T基因型(CC、CT、TT)分布频率分别84.7%、4.7%、10.7%,正常对照组分别为94.7%、2.0%、3.3%,两组基因型分布频率差异具有统计学意义(χ2=6.2,P<0.05);其中试验组MTHFR基因TT纯合子的分布频率高于正常对照组;试验组 MTHFR 基因 T、C 等位基因频率分别为87.0%、13.0%,正常对照组为95.7%、4.3%,两组差异具有统计学意义(χ2=14.2,P<0.05)。结论：PACG患者血浆中Hcy的浓度及MTHFR基因型TT纯合子的分布频率高于正常对照组,说明高Hcy水平及其代谢相关因素可能与PACG的发病与发展密切相关。     

同型半胱氨酸、尿酸、乳酸脱氢酶及肌酸激酶与糖尿病视网膜病变的关系

目的探讨血清同型半胱氨酸(homocysteine,Hcy)、尿酸(uric acid,UA)、乳酸脱氢酶(lactate dehydrogenase,LDH)、肌酸激酶(creatine kinase,CK)和糖尿病视网膜病变的相关性。方法采用眼底荧光血管造影诊断糖尿病视网膜病变。在一定时间内,随机抽取有或无视网膜病变的糖尿病患者及无糖尿病的年龄相关性白内障或眼表疾病患者,分为有视网膜病变的糖尿病组(46例)、无视网膜病变的糖尿病组(45例)和对照组(46例)。测定各组的血清Hcy、UA、LDH、CK水平。结果 3组在性别、年龄上以及高血压病、脑血管意外、血栓栓塞性疾病、缺血性心脏病的发病率上差异均无统计学意义(均为P>0.05),具有可比性。和对照组比较,糖尿病患者血清中Hcy、LDH均显著性升高(均为P<0·05),UA、CK差异均无统计学意义(均为P>0·05),并且糖尿病患者中,有视网膜病变者血清中Hcy水平(15.71±4.56)μmol·L-1显著高于无视网膜病变者(12.61±5·89)μmol·L-1(P<0.05)。结论糖尿病患者中,Hcy、LDH升高是糖尿病并发症增多的风险因素,并且Hcy与糖尿病视网膜病变的发生有关。     

糖尿病视网膜病变与血清胆红素水平的关系

目的探讨糖尿病视网膜病变(diabetic retinopathy,DR)与血清胆红素水平的关系。方法选取新乡医学院第三附属医院内分泌科2010年5月至2011年9月住院的2型糖尿病患者96例,根据眼底检查结果分为无DR(non-DR,NDR)组(55例)和DR组(41例),比较2组患者血清胆红素水平的差异。结果 DR组的血清总胆红素为(8.19±1.67)μmol·L-1,直接胆红素为(2.37±0.62)μmol·L-1,间接胆红素为(5.82±1.60)μmol·L-1,均低于NDR组的(11.58±2.38)μmol·L-1、(3.51±0.85)μmol·L-1和(8.20±2.63)μmol·L-1,两组比较差异均有统计学意义(均为P<0.01)。结论 DR患者存在血清胆红素的降低,这可能与DR的发生发展相关。     

同型半胱氨酸与2型糖尿病合并前部缺血性视神经病变的相关性

目的：探讨血清同型半胱氨酸(Hcy)水平与2型糖尿病合并前部缺血性视神经病变(AION)的关系。

方法：选取2016-01/2019-04于河北省眼科医院就诊的2型糖尿病患者100例，依据是否并发AION分为未合并AION组(A组，53例)和合并AION组(B组，47例)，另选取同期健康体检者38例为对照组(C组)。检测受检者血Hcy、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、肌酐(Cr)、糖化血红蛋白(HbA1c)等生化指标和血压、最佳矫正视力(BCVA)情况，分析2型糖尿病合并AION患者血Hcy水平与上述临床指标的相关性。

结果：B组受检者血Hcy水平(13.87±5.02μmol/L)显著高于A组(11.83±3.49μmol/L)和C组(11.06±3.62μmol/L)(均P<0.05)，且B组受检者HHcy发生率(36.2%)明显高于A组(11.3%)和C组(10.5%)。校正年龄、TG、LDL-C、Cr、糖尿病病程、收缩压和舒张压后，2型糖尿病合并AION患者血Hcy水平与HbA1c水平呈正相关(r=0.517，P=0.001)，与BCVA呈负相关(r=-0.353，P=0.026)。

结论：血清Hcy可能参与了2型糖尿病患者AION的发病过程，其可作为防治2型糖尿病合并AION的潜在靶点。     

糖尿病合并白内障患者血清及房水中铬元素含量测定及分析

目的:检测2型糖尿病合并老年性白内障患者血清及眼房水中铬元素的含量,并探讨其临床意义。方法:采用石墨炉原子吸收法测定患者血清及房水中铬的含量,试验组:糖尿病(2型)合并白内障患者19例,对照组:健康的老年性白内障患者21例。结果:试验组的血清及房水铬元素含量分别为(3.79±1.17)μg/L,(0.97±0.35)μg/L,明显低于对照组(4.50±0.92)μg/L,(1.43±0.68)μg/L,且两组比较差异均有统计学意义(t=-2.139,P<0.05;t=-2.653,P<0.05),两组血清及房水中铬元素含量无显著相关性(r=-0.142,P>0.05)。结论:铬元素在糖尿病合并老年性白内障患者的发生及发展过程中具有重要作用。     

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye-hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye-hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.     

Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: Evaluation and management

Paraneoplastic syndromes involving the visual system are a heterogeneous group of disorders occurring in the setting of systemic malignancy. Timely recognition of one of these entities can facilitate early detection and treatment of an unsuspected, underlying malignancy, sometimes months before it would have otherwise presented, and gives the patient an increased chance at survival. We outline the clinical features, pathogenesis, and treatment strategies for the retinal- and optic nerve–based paraneoplastic syndromes: cancer-associated retinopathy; melanoma-associated retinopathy; paraneoplastic vitelliform maculopathy; bilateral diffuse uveal melanocytic proliferation; paraneoplastic optic neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome. Distinguishing these disorders from their non-paraneoplastic counterparts (e.g., autoimmune-related retinopathy and optic neuropathy, and acute zonal occult outer retinopathy) and determining appropriate systemic evaluation for the responsible tumor can be challenging. In addition, we discuss the utility and interpretation of autoantibody testing.     

Sensitivity to first- and second-order motion and form in children and adults

We compared the sensitivity of adults and children aged 3-10 years to first- and second-order motion and form. For first-order stimuli, at all ages sensitivity was better for motion than form, and motion thresholds were better at 6 Hz than at 1.5 Hz. For second-order stimuli, at all ages sensitivity was better for form than motion, and motion thresholds were better at 0.25 cyc/deg than at 1 cyc/deg. Thresholds became adult-like later for motion than for form and later for first-order than second-order stimuli. For first-order stimuli, the changes with age were larger and more protracted.     

Nodes and nodal points and lines in eyes and other optical systems

The typical stigmatic optical system has two nodal points: an incident nodal point and an emergent nodal point. A ray through the incident nodal point emerges from the system through the emergent nodal point with its direction unchanged. In the presence of astigmatism nodal points are not possible in most cases. Instead there are structures, called nodes in this paper, of which nodal points are special cases. Because of astigmatism most eyes do not have nodal points a fact with obvious implications for concepts, such as the visual axis, which are based on nodal points. In order to gain insight into the issues this paper develops a general theory of nodes which holds for optical systems in general, including eyes, and makes particular allowance for astigmatism and relative decentration of refracting elements in the system. Key concepts are the incident and emergent nodal characteristics of the optical system. They are represented by 2 × 2 matrices whose eigenstructures define the nature and longitudinal position of the nodes. If a system's nodal characteristic is a scalar matrix then the node is a nodal point. Otherwise there are several possibilities: Firstly, a node may take the form of a single nodal line. Second, a node may consist of two separated nodal lines reminiscent of the familiar interval of Sturm although the nodal lines are not necessarily orthogonal. Third, a node may have no obvious nodal line or point. In the second and third of these classes one can define mid-nodal ellipses. Astigmatic systems exist with nodal points and stigmatic systems exist with no nodal points. The nodal centre may serve as an approximation for a nodal point if the node is not a point. Examples in the Appendix , including a model eye, illustrate the several possibilities.     

Nutritional antioxidants and age-related cataract and maculopathy

Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that the same nutritional practices that are associated with prolonged eye function will also be associated with delayed age-related compromises to other organs, and perhaps, aging in general, (2) surgical resources are insufficient to provide economic and safe surgeries for cataract and do not provide a cure for ARM, and (3) there will be considerable financial savings and improvements in quality of life if health rather than old age is extended, particularly given the rapidly growing elderly segment of our population. It is clear that oxidative stress is associated with compromises to the lens and retina. Recent literature indicates that antioxidants may ameliorate the risk for ARC and ARM. Given the association between oxidative damage and age-related eye debilities, it is not surprising that over 70 studies have attempted to relate antioxidant intake to risk for ARC and ARM. This article will review epidemiological literature about ARC and ARM with emphasis on roles for vitamins C and E and carotenoids. Since glycation and glycoxidation are major molecular insults which involve an oxidative stress component, we also review new literature that relates dietary carbohydrate intake to risk for ARC and ARM. To evaluate dietary effects as a whole, several studies have tried to relate dietary patterns to risk for ARC. We will also give some attention to this emerging research. While data from the observational studies generally support a protective role for antioxidants in foods or supplements, results from intervention trials are less encouraging with respect to limiting risk for ARC/ARM prevalence or progress through antioxidant supplementations, or maintaining higher levels of antioxidants either in diet or blood. Without more information it is difficult to parse these results. It would be worthwhile to determine why the various types of studies are not yielding similar results. However, there are many common insults and mechanistic compromises that are associated with aging, and proper nutrition early in life may address some of these compromises and provide for extended youthful function later in life. Indeed, proper nutrition, possibly including use of antioxidant supplements for the nutritionally impoverished, along with healthy life styles may provide the least costly and most practical means to delay ARC and ARM. Further studies should be devoted to identifying the most effective strategy to prevent or delay the development and progress of ARC/ARM. The efforts should include identifying the right nutrient(s), defining useful levels of the nutrient(s), and determining the age when the supplementation should begin.     

Ethics and optometry: concepts and applications

Ethics refers both to the study of behaviour, and moral principals. The related concepts of justice and law are also relevant to optometry. A profession typically claims specialist knowledge and ethical behaviour – putting the interests of clients above its own. However, professional codes fail as ethical directives, and their goals are questioned. Beginning with broad principles, institutional ethics and issues of general health care provision are considered, and applications to optometry are made. Ethical theory can guide us in interacting with our patients, utilising resources and ordering priorities. The conservative approach to consumerism and advertising is defended on the basis of protecting public and professional interests. Ethical behaviour can be fostered, and this process should begin in undergraduate education.     

Exogenous attention and color perception: performance and appearance of saturation and hue

Exogenous covert attention is an automatic, transient form of attention that can be triggered by sudden changes in the periphery. Here we test for the effects of attention on color perception. We used the methodology developed by Carrasco, Ling, and Read [Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7 (3) 308-313] to explore the effects of exogenous attention on appearance of saturation (Experiment 1) and of hue (Experiment 2). We also tested orientation discrimination performance for single stimuli defined by saturation or hue (Experiment 3). The results indicate that attention increases apparent saturation, but does not change apparent hue, notwithstanding the fact that it improves orientation discrimination for both saturation and hue stimuli.     

Aberration and contrast sensitivity comparison of aspherical and monofocal and multifocal intraocular lens eyes

BACKGROUND: Higher-order aberrations and contrast sensitivity were evaluated in patients who underwent phacoemulsification cataract extraction followed by implantation of aspherical, monofocal or multifocal intraocular lens (IOL) replacements. METHODS: In this comparative trial, 124 patients with an average age of 66.8+/-5.2 years and their 124 eyes were randomly divided into three surgical implantation groups to receive one of three types of IOLs in replacement of cataract lenses. The patients of group 1 were given an aspherical IOL Z9001 (AMO, Santa Ana, CA, USA) replacement, and group 2 was implanted a monofocal IOL SA60AT (Alcon, Fort Worth, TX, USA) and group 3 the multifocal IOL SA40N (AMO). Post-surgical best-corrected visual acuity, corneal aberrations, total ocular aberrations, pupil diameters, capsulorhexsis sizes and contrast sensitivity were measured and compared. RESULTS: There was no statistical difference for mean best-corrected visual acuity, pupil diameter, curvilinear capsulorhexis size and corneal aberration among the three groups. For the spherical aberration, fourth-order higher-order aberration and total ocular higher-order aberration, the SA40N group was higher than the SA60AT group and the SA60AT group was higher than the Z9001 group, and the differences between the three groups were statistically significant for these measurements. Contrast sensitivity was higher for the Z9001 group than the SA60AT group and the SA60AT group was higher than the SA40N group, and the difference was statistically significant in all the spatial frequencies of 3, 6, 12 and 18. CONCLUSIONS: Although the multifocal IOL can provide near vision, it can increase higher-order aberration and negatively influence contrast sensitivity. However, the aspherical IOL can reduce aberration and improve contrast sensitivity as compared with the monofocal IOL.