摘  要  對(duì)西寧市82例不同程度近視眼疾的中學(xué)生及28例正常視力的對(duì)照學(xué)生的頭發(fā)鋅含量采用火焰原子吸收光譜法進(jìn)行了測(cè)定，分析結(jié)果表明：近視眼患者發(fā)鋅Ⅰ、Ⅱ組含量低于正常對(duì)照組(P<0.01)。男、女性發(fā)鋅含量差異無(wú)顯著性。對(duì)所有近視患者的發(fā)鋅含量與近視程度作相關(guān)分析，結(jié)果表明：近視程度與發(fā)鋅含量呈負(fù)相關(guān)關(guān)系(r＝-0.4302，P＜0.01)。

    關(guān)鍵詞   中學(xué)生  發(fā)鋅  視力

 

    鋅是人體必需的生命元素，是維持機(jī)體正常新陳代謝的要素。近年來(lái)在免疫、遺傳營(yíng)養(yǎng)、優(yōu)生優(yōu)育、兒童保健、抗衰老及各種疾病病因的研究與防治等方面取得了一系列的研究成果。研究表明，鋅與人體眼科疾病關(guān)系密切^[1]。人體各種器官中，眼組織中含有較高濃度的鋅，鋅存在于眼組織中的各種鋅激酶或鋅酶中，其中主要是睫狀體中的碳酸酐酶，角膜中的膠原酶、晶狀體中的亮氨酸基鈦酶和視網(wǎng)膜脫氫酶，因而，眼組織對(duì)缺鋅特別敏感^[2]。白內(nèi)障病人晶體房水和血清中鋅的含量顯著低于正常值，而且隨著年齡增長(zhǎng)而逐漸降低^[3,4]。體內(nèi)鋅降低易引發(fā)夜盲癥^[5]。我國(guó)人口中近視眼己成為常見病，尤其中學(xué)生近視眼思考迅速增加，其病因過去一直認(rèn)為是由于長(zhǎng)期用眼不良、遺傳、疾病、體質(zhì)等因素所致．新近研究表明：體內(nèi)微量元素缺乏亦是重要因素^[6,7]。本文研究了中學(xué)生視力與頭發(fā)中鋅含量的關(guān)系，旨在探討近視眼發(fā)病的其他機(jī)理，為尋求眼科保健與預(yù)防近視的醫(yī)學(xué)新方法提供科學(xué)依據(jù)。

1  對(duì)象與方法

1．1  對(duì)象

    近視眼組和對(duì)照組均選自西寧市第七中學(xué)的初三學(xué)生，其中近視眼組82例，對(duì)照組28例，年齡14—17歲，平均年齡為15.5土l.5歲：學(xué)生家庭出身為干部的占63.6%，工人占36.4%。生活水平普遍較好。各組男、女比例基本均等，身體健康，無(wú)嚴(yán)重疾病史．近視組除眼睛視力較低外．無(wú)其它病變，發(fā)育狀況與對(duì)照組相同。為了排除影響發(fā)鋅含量的外在因素，選擇了在西寧居住5年以上，居住區(qū)無(wú)嚴(yán)重的鋅元素環(huán)境污染的學(xué)生。近視眼組分為近視組Ⅰ(鏡片度數(shù)為100º以上，27例)；近視組Ⅱ(250º以上，28例)；近視組Ⅲ(400º～700º，27例)。視力以標(biāo)準(zhǔn)對(duì)數(shù)視力表檢查、視力表有充足的光線照明，被檢查者距視力表5m，兩眼分別檢查，先右后左^[8]。

1. 2  方法    發(fā)祥均采自學(xué)生后枕部，用不銹鋼剪刀剪取約l克，用0.2%海鷗牌洗滌劑浸泡4h后，自來(lái)水沖洗干凈，再用二次蒸餾水沖洗3～4次，在50～60℃烘箱烘干，準(zhǔn)確稱取0.3～0.5克樣品，在450～500℃灰化2h，灰分用1：1HN0₃溶解．50ml容量瓶中用去離子水定溶。在GGX－5型原子吸收儀上用火焰法直接測(cè)定鋅含量。國(guó)家人發(fā)標(biāo)準(zhǔn)物質(zhì)GBW-08551和實(shí)際樣品標(biāo)準(zhǔn)回收率為96.8～102.4%。

    統(tǒng)計(jì)方法結(jié)果以x土s表示，顯著性檢驗(yàn)用方差分析和Dunnett檢驗(yàn)．并作直線相關(guān)分析。

2  結(jié)果

2．1  近視組與對(duì)照組一般生理指標(biāo)

近視組與對(duì)照組一般生理指標(biāo)見表1。

 

組別               視力                      鏡片度

             右眼        左眼            右眼        左眼

近視Ⅰ     4.33土0.33    4.38土0.33  205.4土37.7   189.4土37.8

近視Ⅱ     4.29土0.25    4.32土0.25  309.8土51.1   307.1土52.6

近視Ⅲ     4.16土0.22    4.22土0.24  492.6土103.5  489.8土112.7

對(duì)照組     5.03土0.21    5.04土0.17      －          －

 

2.2  發(fā)鋅含量與視力的關(guān)系

各組發(fā)鋅分析結(jié)果見表2。近視Ⅰ、Ⅱ和Ⅲ組發(fā)鋅均低于正常對(duì)照組，且近視程度越高，發(fā)鋅含量越低。近視Ⅰ組與對(duì)照組比較，發(fā)鋅含量差異無(wú)顯著性(P＞0.05)，而近視Ⅰ、Ⅱ、Ⅱ組發(fā)鋅含量與對(duì)照組比較差異有高度顯著性(P＜0.01)。對(duì)所有近視[－Ⅲ組的近視程度與發(fā)鋅含量之間作相關(guān)性分析。結(jié)果表明，它們之間是負(fù)相關(guān)關(guān)系(r＝－O.4302，tr＝4.262，P＜0.01)。

 

  組別    n       χ土S          P值

 對(duì)照組   28   196.1土29.35      －

 近視Ⅰ   27   187.9土22.52    >0.05

 近視Ⅱ   28   179.5土22.50    <0.01

 近視Ⅲ   27   171.9土19.72    <0.01

 

2．3  性別與發(fā)鋅含量

    近視組與對(duì)照組不同性別發(fā)鋅含量見表3。各組發(fā)鋅男性略高于女性，但經(jīng)t檢驗(yàn)?zāi)信�性之間發(fā)鋅含量的差別均無(wú)顯著性差異(P＞0.05)。

 

  組別   性別     n        χ土S

 近視Ⅰ   男     13    192.0土24.03

          女     14    189.6土12.13

 近視Ⅱ   男     13    178.6土21.31

          女     15    176.1土20.62

 近視Ⅲ   男     13    171.5土14.36

          女     14    170.3土20.21

 對(duì)照組   男     13    199.3土30.65

      女     15    196.5土27.07

 

3         討論

微量元素鋅與人體健康的研究報(bào)道甚多^[2]。近年研究表明在我國(guó)缺鋅與缺維生素一樣常見。缺鋅可引起人體一系列病變、尤其對(duì)少年兒童的正常生長(zhǎng)發(fā)育帶來(lái)嚴(yán)重的影響，使發(fā)育受阻，智能低下，免疫機(jī)能被抑制，導(dǎo)致異食癖及食欲減退。由于人體眼組織中富含鋅，因而眼組織對(duì)鋅元素的缺乏尤為敏感^[3]。

    賈鐳等^[4]研究表明，大學(xué)一年級(jí)學(xué)生急性視力下降與體內(nèi)微量元素缺乏有關(guān)。30例題者平均發(fā)鋅179.69土25.14mg/kg，而30例正常對(duì)HB學(xué)生平均發(fā)鋅為280.11土69.34mg/kg，差異極其顯著。本研究結(jié)果與文獻(xiàn)報(bào)道一致，缺鋅是導(dǎo)致視力下降的主要因素之一。因?yàn)殇\在體內(nèi)蛋白質(zhì)生物合成過程中發(fā)揮重要作用，缺乏時(shí)一方面將影響視蛋白及神經(jīng)介質(zhì)的合成，從而影響眼睛的神經(jīng)興奮性功能，當(dāng)缺乏時(shí)導(dǎo)致眼部神經(jīng)肌肉的收縮與舒張功能受阻，從而影響眼部肌肉的正常生理功能，導(dǎo)致視力下降。

    有關(guān)鋅與視力下降的關(guān)系目前還不很清楚，從本結(jié)果看出，視力與發(fā)鋅含量關(guān)系密切。發(fā)鋅隨近視程度的增加而下降。而近視學(xué)生鋅偏低的原因很多，最主要的是學(xué)習(xí)緊張，影響睡眠與食欲，以及偏食等，因而在預(yù)防中學(xué)生視力下降中．應(yīng)特別注意膳食中鋅的攝入。關(guān)于中學(xué)生視力降低，發(fā)鋅下降與其他臨床表現(xiàn)之間的關(guān)系有待進(jìn)一步研究。

同時(shí)本研究結(jié)果顯示，發(fā)鋅監(jiān)測(cè)可作為視力下降或其他眼科疾病調(diào)查與診治的輔助手段。

 

參考文獻(xiàn)   

1.       汪芳潤(rùn)．微量元素鋅與眼．國(guó)外醫(yī)學(xué)眼科分冊(cè)，1982；[6]：1

2.       王夔主編．生命科學(xué)中的微量元素(下卷)．北京：中國(guó)計(jì)量出版社、1992：137-138

3.       馬慶余．微量元素－老年性白內(nèi)障的關(guān)系探討．微量元素與健康研究．1993；特刊：39

4.       李小梁，梁業(yè)成，李增禧等．補(bǔ)鋅對(duì)兔眼晶體、清水、血清中其他微量元素的影響．微量元素與健康研究．1993；10(1)：10

5.         周大驤，鋅與人體健康．新疆環(huán)境保護(hù)．1988；(4)：56

 

 

Invest Ophthalmol Vis Sci 2004;45: E-Abstract 5161.

© 2004 ARVO

5161—B485

 

H. Bahrami, M. Melia, L. Yang, J. Stone, D. Bourdeau, F. Eshraghi, D. Maldenovich and G. Dagnelie

Wilmer Eye Institute, Department of Ophthalmology, Johsn Hopkins University, Baltimore, MD

 

Commercial Relationships: H. Bahrami, None; M. Melia, None; L. Yang, None; J. Stone, None; D. Bourdeau, None; F. Eshraghi, None; D. Maldenovich, None; G. Dagnelie, None.

 

Grant Identification: NEI Grant R03 EY 14416 and NCCAM Grant R21 AT00292

 

Purpose: To evaluate the effectiveness of lutein supplementation in preventing progressive vision loss in patients with retinitis pigmentosa (RP)

 

Methods: Started in May 2001, as a combined phase I/II trial, 45 adult patients with retinitis pigmentosa were enrolled in this cross–over trial and randomized to two groups. One group received lutein supplementation and for 24 weeks (0 mg/d/PO for 12wks followed by 30 mg/d/PO) and then placebo for 24 weeks, Washout Group. In the other group, Buildup Group, placebo (24 weeks) was administered prior to lutein.. Subjects received multivitamin supplementation in addition to their lutein or placebo throughout the trial. Subjects visual function was measured by multiple tests, including visual acuity, contrast sensitivity, and visual field at up to three levels of illumination at baseline and every 6 weeks in the lab. Also, these tests were performed every week using a previously validated PC–based test in the home.

 

Results: Data from 35 subjects are reported here, and has been analyzed using the Generalized Estimating Equations (GEE) based on intention–to–treat analysis; 16 in the Washout Group, the other 19 in the Buildup Group. Analysis showed a significant beneficial effect of lutein on visual acuity (p<0.001), while contrast sensitivity was worsened significantly (p<0.001) during lutein usage; over the full trial period, though, contrast sensitivity among all subjects improved significantly. Lutein did not have a significant effect in preserving the visual field, but subjects in the Washout Group had significantly slower loss of visual field than those in the Buildup Group (p value: 0.02). No adverse effects were observed for lutein, while one patient could not tolerate multivitamin.

 

Conclusions: Lutein appears to be an effective supplement for preservation of visual function in patients with retinitis pigmentosa, which is important in view of the lack of effective intervention for these patients. Lutein appears to have differential effects on different components of vision loss in the same patients. The anomalous improvement of contrast sensitivity during washout may be attributed to a delayed incorporation and effect of lutein in the retina. Since all subjects were receiving multivitamin throughout the trial, preservation of visual function may in part be attributed to multivitamin, or its combination with lutein. Long–term lutein and multivitamin effects on vision in RP patients need to be further investigated.

 

Key Words: retinitis clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • low vision

 

H. Bahrami, M. Melia, L. Yang, J. Stone, D.等醫(yī)學(xué)博士為了證明在色素性視網(wǎng)膜炎患者中，葉黃素補(bǔ)充能夠保存他們的視力功能，做了一個(gè)以安慰劑控制的雙盲隨機(jī)臨床實(shí)驗(yàn)。論文發(fā)表于《Invest Ophthalmol》（2004;45: E-Abstract 5161.）

目的：評(píng)估葉黃素補(bǔ)充對(duì)防止RP患者進(jìn)行性失視的有效性。方法是：將45個(gè)患有色素性視網(wǎng)膜炎的成年人隨機(jī)分成兩組，做交叉實(shí)驗(yàn)。一組接受葉黃素補(bǔ)充24周（前12周給予每天10mg量，后12周增加到30mg每天。），另一組使用安慰劑。在實(shí)驗(yàn)過程中，兩組患者均服用額外的多種維生素補(bǔ)充。結(jié)果：分析顯示，葉黃素組對(duì)視力靈敏度提高作用有顯著性意義（p<0.001）。但葉黃素對(duì)保存視野沒有太大的作用。

結(jié)論：葉黃素是能有效改善視網(wǎng)膜色素變性患者視力功能的補(bǔ)充劑。

 

 

 

Invest Ophthalmol Vis Sci 2003;44: E-Abstract 969.

© 2003 ARVO

969

 

Macula Pigment Optical Density is Enhanced with Lutein Supplementation Independent of AREDS AMD Disease Stage

S.P. Richer1, M. Tsipursky1 and J. Pulido2

1 Eye Clinic 112E, Department of VA Medical Ctr, North Chicago, IL, United States

2 Retina Service, Ophthalmology, University of Illinois, Chicago, IL, United States

 

 

Commercial Relationships: S.P. Richer, Kemin Foods, Inc Des Moine, IA F, R; Nutraceutical Sciences Institute, (Boynton Beach, FL). F; M. Tsipursky, None; J. Pulido, None.

 

Abstract

 

Purpose: Emerging evidence suggests lutein has therapeutic effects on macula pigment optical density (MPOD) and vision in atrophic AMD. Little is known about lutein intervention effect(s) vs. AMD stage. We evaluated AREDS retinal disease stage vs. MPOD/visual function in a subset of patients in the Veterans LAST Study (ARVO 2001, # 2542).

 

Methods: 35 mm retinal color slides of (n=60) primarily male veterans with atrophic AMD (ICD9 362.51) were ranked as to AREDS stage by a retinal specialist masked as to treatment group (10 mg non-esterified lutein vs. maltodextrin placebo). Using methodology defined in the LAST Study, MPOD, glare recovery (GR) and contrast sensitivity (CSF) were evaluated over 1 year by AREDS subgroup (stage II, II & IV), and subjected to Friedman’s non-parametric statistics.

 

Results: Lutein supplementation enhanced MPOD in AREDS geographic stage IV (P=0.05), stage III (P<0.09) and stage II (P=0.05). Lutein quickened glare recovery independent of AREDS retinal stage (mean(sec) +/-SD at baseline and after 12 months of lutein: stage IV, n=7, 102 +/-72 vs 80 +/- 63, (P=0.05), stage III, n=11, 82 +/-58 vs. 38 +/- 28 (NS), stage II, n=10, 111 +/- 76 vs 52 +/- 44 (P=0.02). Lutein supplementation had no significant effect on CSF for AREDS stage II or III, however significantly improved CSF at 3 of 4 spatial frequencies in geographic stage IV advanced disease (stage IV @ 6cc/deg (P=0.02); 12cc/deg (P=0.03); 18cc/deg (P=0.006).

 

Conclusions: This small population, brief time frame study demonstrates 1) Lutein supplementation increases MPOD at each AREDS stage compared with placebo; 2) Lutein may be beneficial at all stages of atrophic AMD; 3) GR appears the best indicator of enhanced macula pigment.

Support: Kemin Foods Inc, (Des Moines, IA), Nutraceutical Sciences Institute, (Boynton Beach, FL).

 

Key Words: age-related macular degeneration • macular pigment

 

S.P. Richer, M. Tsipursky and J. Pulido共同研究了葉黃素在AREDS的視網(wǎng)膜疾病階段與黃斑色素光學(xué)密度或視力功能的關(guān)系。論文發(fā)表于《Invest Ophthalmol》（2003;44: E-Abstract 969.）。方法是：選取35mm視網(wǎng)膜彩色幻燈的男性萎縮型AMD(ICD9 362.51)患者（n＝60）為治療組（服用10mg非酯化葉黃素和麥芽糊精安慰劑）。在最后階段的研究中，依照Friedman的非參數(shù)統(tǒng)計(jì)，評(píng)估MPOD、GR、CSF在超過1年的AREDS研究（階段Ⅱ,Ⅱ&Ⅳ）的情況。結(jié)果：葉黃素補(bǔ)充能夠增強(qiáng)在AREDS中的階段Ⅳ (P=0.05)，階段Ⅲ (P<0.09)的MPOD，同時(shí)加快眩光的恢復(fù)。在AREDS的階段Ⅱ或Ⅲ，葉黃素對(duì)對(duì)比靈敏度沒有明顯功效，但在地理階段IV卻能增高對(duì)比靈敏度3/4的空間頻率。

結(jié)論：補(bǔ)充葉黃素相比于安慰劑，在AREDS每個(gè)階段中均能增高M(jìn)POD；葉黃素可能對(duì)萎縮性AMD有效；GR是增強(qiáng)黃斑色素的最佳指標(biāo)。