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Sample records for anisometropia

  1. Predicting aniseikonia in anisometropia.

    Science.gov (United States)

    Ryan, V I

    1975-02-01

    In estimating the amount of aniseikonia that may be present in any given case of anisometropia, it is usual to apply the "rule of thumb" approach. The "rule" states that for each diopter of anisometropia, the amount of aniseikonia to be expected is 1 1/2 to 2 percent. The rule is based upon an average value computed for theoretical amounts of aniseikonia in many possible situations that can occur, some of which have little likelihood of being found in everyday clinical practice. Applied to many cases of anisometropia that are common, the rule leads to extreme overstimates and is grossly misleading, often resulting in the mishandling of patients. In this paper, a number of typical cases are dealt with in the refutation of the use of "the rule."

  2. Componentes oculares em anisometropia The ocular components in anisometropia

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    David Tayah

    2007-06-01

    Full Text Available OBJETIVO: Comparar as correlações dos componentes oculares (comprimento axial, comprimento do segmento anterior, poder médio da córnea, profundidade da câmara vítrea e poder refrativo equivalente com o erro refrativo total do olho portador da menor e da maior ametropia em anisométropes. MÉTODOS: Foi realizado um "survey" analítico conduzido em população de 68 anisométropes de duas ou mais dioptrias atendida no Ambulatório da Clinica Oftalmológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Os anisométropes foram submetidos à refração estática objetiva e subjetiva, ceratometria e biometria ultra-sônica. RESULTADOS: Não houve diferença significativa entre os valores dos componentes oculares medidos dos olhos portadores da menor e da maior ametropia. Os olhos portadores da menor ametropia apresentaram as mesmas correlações significantes observadas em olhos emétropes, ou seja, correlação da refração com comprimento do segmento anterior e comprimento axial, e correlação do comprimento axial com poder corneano e profundidade da câmara vítrea. Os olhos portadores da maior ametropia apresentaram correlação significante da refração com o comprimento axial e do comprimento axial com a profundidade da câmara vítrea. Ainda em ambos os olhos observou-se correlação significante do poder do cristalino com a profundidade da câmara anterior. CONCLUSÃO: Os olhos portadores da menor ametropia desenvolveram as correlações mais freqüentemente observadas nos olhos emétropes. Os olhos portadores da maior ametropia não desenvolveram as mesmas correlações dos emétropes.PURPOSE: To asses the correlation between ocular components (axial length, anterior segment length, corneal power, vitreous length and equivalent power of the eye and refractive error in eyes with higher and lower ametropia of subjects with anisometropia. METHODS: An analytical survey was carried out in 68 patients

  3. Reduced aniseikonia in axial anisometropia with contact lens correction.

    Science.gov (United States)

    Winn, B; Ackerley, R G; Brown, C A; Murray, F K; Prais, J; St John, M F

    1988-01-01

    Aniseikonia, although present in isometropia, is associated principally with anisometropia and is widely thought to be the result of differences in the retinal image size presented to each eye. This assumes that equating retinal image size results in congruous cortical images. To test this assumption 1 refractive and 17 axial anisometropic subjects were examined to determine the aniseikonia present when corrected with spectacles and contact lenses. Contrary to many previous predictions, based upon Knapp's Law, the presence of equal retinal images resulted in larger aniseikonias than observed when the eyes were presented with unequal retinal images. This suggests that non-optical components have a significant role in the production of the cortical image, and this therefore requires a shift in the way the management of anisometropia is considered clinically. Contact lens correction maintains the aniseikonia at a minimum level in axial as well as refractive anisometropia and offers the clinician an acceptable practical alternative when prescribing for these patients.

  4. Epidemiologic study of anisometropia in students of Natal, Brazil Estudo epidemiológico da anisometropia em estudantes da cidade de Natal, Brasil

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    Carlos Alexandre de Amorim Garcia

    2005-02-01

    Full Text Available PURPOSE: To perform an epidemiologic study in students in Natal/Brazil, with relation to refractional anisometropia, evaluating criteria such as: gender, age, and association with strabismus and amblyopia. METHODS: A study of 1,024 students randomly selected from several districts of Natal/Brazil was undertaken by the Department of Ophthalmology of the Federal University of Rio Grande do Norte (UFRN, observing the following criteria of > 2 spherical or cylindrical diopter refractional anisometropia relating it to sex, age, association with strabismus, amblyopia and anisometropia classification. RESULTS: We found a prevalence of 2% (N=21 anisometropia in the students. The female gender predominated with 81% (N=17. In students with anisometropia, we observed an association with strabismus in 9.5% of cases (N=2, both with exotropia. The association of anisometropia with amblyopia occurred in 47.6% of the cases (N=10, with 8 cases of unilateral amblyopia and 2 cases of bilateral amblyopia. CONCLUSIONS: There was a predominance of anisometropia in females, and an increased prevalence of strabismus and amblyopia in students with anisometropia.OBJETIVO: Realizar um estudo epidemiológico em estudantes de Natal/Brasil, com relação à anisometropia refracional, avaliando os seguintes critérios: sexo, idade e associação com estrabismo e ambliopia. MÉTODOS: Foram estudados 1.024 estudantes, randomicamente selecionados, pertencentes aos diversos distritos da cidade de Natal/Brasil, pelo Departamento de Oftalmologia, da Universidade Federal do Rio Grande do Norte (UFRN, observando os seguintes aspectos, quanto à anisometropia > 2 dioptrias esférica ou cilíndrica, sexo, idade, associação com estrabismo e ambliopia, e os tipos de anisometropia. RESULTADOS: Encontrou-se prevalência de anisometropia de 2% (N=21 nos estudantes. O sexo feminino predominou com 81% (N=17. Nos estudantes com anisometropia, observou-se associação com estrabismo em 9

  5. Dominant Eye and Visual Evoked Potential of Patients with Myopic Anisometropia

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    Qing Wang

    2016-01-01

    Full Text Available A prospective nonrandomized controlled study was conducted to explore the association between ocular dominance and degree of myopia in patients with anisometropia and to investigate the character of visual evoked potential (VEP in high anisometropias. 1771 young myopia cases including 790 anisometropias were recruited. We found no significant relation between ocular dominance and spherical equivalent (SE refraction in all subjects. On average for subjects with anisometropia 1.0–1.75 D, there was no significant difference in SE power between dominant and nondominant eyes, while, in SE anisometropia ≥1.75 D group, the degree of myopia was significantly higher in nondominant eyes than in dominant eyes. The trend was more significant in SE anisometropia ≥2.5 D group. There was no significant difference in higher-order aberrations between dominant eye and nondominant eye either in the whole study candidates or in any anisometropia groups. In anisometropias >2.0 D, the N75 latency of nondominant eye was longer than that of dominant eye. Our results suggested that, with the increase of anisometropia, nondominant eye had a tendency of higher refraction and N75 wave latency of nondominant eye was longer than that of dominant eye in high anisometropias.

  6. Refração e seus componentes em anisometropia Refraction and its components in anisometropia

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    David Tayah

    2009-02-01

    Full Text Available OBJETIVO: Em anisométropes comparar os valores médios individuais dos componentes oculares de ambos os olhos, correlacionar as diferenças dos componentes com as diferenças de refração; e identificar o menor número de fatores que contenham o mesmo grau de informações expressas no conjunto de variáveis que influenciam a diferença refrativa. MÉTODOS: Realizou-se estudo transversal analítico em população de 77 anisométropes de 2 D ou mais, atendida no ambulatório de Oftalmologia do Hospital Universitário da Faculdade de Medicina Nilton Lins, Manaus. RESULTADOS: Os anisométropes foram submetidos à refração estática objetiva e subjetiva, ceratometria e biometria ultrassônica A-scan. A análise dos dados foi feita por meio dos seguintes modelos estatísticos: análise univariada, multivariada, de regressão múltipla e fatorial. CONCLUSÕES: Não houve diferenças significativas na comparação dos valores médios individuais dos componentes oculares entre os olhos. Houve correlação negativa média entre a diferença refrativa e a diferença de comprimento axial (r= -0,64 (pPURPOSE: To compare the individual means of ocular components of both eyes in patients with anisometropia; to correlate the differences of the components with refractive differences; and to identify the smallest number of factors that contain the same level of information expressed in the set of variables that influence refractive difference. METHODS: An analytical transversal study was carried out in 77 patients with anisometropia of two or more dioptres seen at the Ophthalmologic Clinic, University Hospital, Nilton Lins Medical School, Manaus. RESULTS: All participants were submitted to ophthalmologic examination which included objective and subjective cycloplegic refractometry, keratometry and ultrasound biometry. Data analysis comprised the following statistical models: univariate, multivariate, multiple and factorial regression analyses. CONCLUSIONS

  7. LASIK em pacientes adultos com alta anisometropia: relato de casos LASIK for high anisometropia in adults: case report

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    Patrícia Ioschpe Gus

    2006-04-01

    Full Text Available OBJETIVO: Avaliar a eficácia da técnica laser in situ keratomileusis (LASIK na redução de anisometropia em adultos, para os quais os tratamentos convencionais não tiveram sucesso. MÉTODOS: Série de casos de três olhos de três pacientes adultos, dois do sexo feminino e um do sexo masculino, com idade entre 28 e 49 anos (média de 38,3 anos, os quais foram submetidos à técnica de LASIK. Dois pacientes foram acompanhados por dezoito meses e um por seis meses após a cirurgia. RESULTADOS: Comparando a acuidade visual corrigida do pré-operatório com a acuidade visual não corrigida do pós-operatório, um olho ganhou duas linhas de visão, um olho manteve-se igual e um olho perdeu uma linha de visão. Todos os olhos se mantiveram sem ametropia esférica, e o astigmatismo não excedeu -0,75 D no pós-operatório. CONCLUSÃO: A técnica LASIK mostrou-se eficaz na correção de alta anisometropia em adultos, melhorando a acuidade visual e as queixas astenopéicas, e diminuindo a anisometropia.PURPOSE: To evaluate the efficacy of the laser in situ keratomileusis (LASIK technique in the reduction of anisometropy in adults, for whom conventional treatment was not successful. METHODS: A sequence of cases of three eyes of three adult patients, two females and one male, age ranging from 28 and 49 years (average 38.3 years, who underwent LASIK. Two patients were followed up for eighteen months and one for six months. RESULTS: Comparing the corrected visual acuity before surgery with the non-corrected visual acuity after surgery, one eye gained two lines of vision, one eye remained the same and one eye lost one line of vision. All eyes remained without spheric refraction, and astigmatism did not exceed - 0.75 D after surgery. There has been an improvement in the symptoms of asthenopia in the three patients. CONCLUSION: The LASIK technique proved to be efficient in the correction of anisometropy in adults, improving visual accuity and asthenopia

  8. Anisometropia and stereopsis%屈光参差与立体视觉

    Institute of Scientific and Technical Information of China (English)

    吴微微; 彭秀军

    2014-01-01

    屈光参差是指两眼屈光度的程度和(或)性质有一定的差别,其主要相关原因是由于双眼眼轴长度发育不平衡。立体视觉是人类和高等动物所特有的一项高级视功能,同时也是人类从事多种工作及日常生活中必备的一种重要功能。屈光参差引起的视网膜像模糊和不等像视是影响立体视觉的主要原因。屈光参差矫正方法不同,对立体视觉的影响也是不同的。%Anisometropia means a certain difference between two eyes in the degree of diopter and ( or ) the nature of diopter.The main associated reason is due to the eyes ocular axial length development imbalance. However, stereopsis is the highest visual function of human beings and higher animals, which is necessary for working people in daily life. The main reason of effecting on binocularity is retinal image blur and aniseikonia caused by uncorrected anisometropia. Different methods of anisometropia correction have different effects on stereo vision.

  9. Effects of aniseikonia, anisometropia, accommodation, retinal illuminance, and pupil size on stereopsis.

    Science.gov (United States)

    Lovasik, J V; Szymkiw, M

    1985-05-01

    The sensitivity of clinical measures of stereoacuity in the detection of interocular differences in retinal images was examined in 50 adults with normal binocularity. Interocular differences in retinal image size (aniseikonia), clarity (anisometropia) and brightness, as well as differences in absolute and relative pupil size (anisocoria) were created in small steps over a large range to determine their effect on threshold levels of stereopsis. Their effect on stereoacuity was measured in both contour (Titmus test) and random dot (Randot test) stereograms. Stereoacuity measured by both types of stereograms decreased in a curvilinear manner for aniseikonic and anisometropic test conditions. Monocular blur caused a more rapid decrease in stereoacuity than induced aniseikonia. Stereoacuity measured by the contour stereogram decreased about 1.8 times faster than that measured by the random dot stereogram during induced aniseikonia and anisometropia. This differential sensitivity suggests that the Titmus test would detect small interocular differences in retinal images more effectively than the Randot test in clinical screening procedures for vision abnormalities. However, both tests can miss clinically significant amounts of aniseikonia and anisometropia, and fail to differentiate the cause of reduced stereopsis. Interocular differences in retinal image brightness and pupil size within a normal physiologic range did not reduce stereopsis to clinically unacceptable levels.

  10. 远、近视性屈光参差视功能对比研究%Comparative study of myopic and hyperopic anisometropia on binocular vision

    Institute of Scientific and Technical Information of China (English)

    罗俊; 漆争艳; 何容; 王平; 唐璟; 向剑波; 杨俊芳

    2014-01-01

    AIM: To investigate the effect of both myopic and hyperopic anisometropia on binocular vision. METHODS: Totally 238 patients with corrected anisometropia and 30 normal children were tested with both stereogram and synoptophore for their near stereoacuity and binocular vision. The correlation of anisometropia and binocular vision was studied statistically. RESULTS:The number of normal near stereoacuity and distance fusion range of myopic anisometropia was significantly higher than that of hyperopic anisometropia. A few of hyperopic anisometropia had normal stereopsis. Most of low anisometropia group had sub -normal stereopsis, while high, severe anisometropia group without stereopsis.Most of myopic anisometropia group had normal stereopsis or sub-normal stereopsis. CONCLUSION:The hyperopic anisometropia produces a more profound effect. Relationship between anisometropia and stereopsis are analyzed according to nature.%目的:对比分析远、近视性屈光参差对患者双眼视功能的影响。  方法:对238例屈光矫正后的屈光参差者和30例正常者进行近立体视和同视机三级视功能检查,并记录其结果。  结果:近视性屈光参差远、近立体视及融合功能正常者的例数高于远视性屈光参差者。远视性屈光参差组有正常立体视者少,低度屈光参差组以亚正常立体视者为主,而高、重度屈光参差组多无立体视;近视性屈光参差组多有正常立体视或亚正常立体视。  结论:近视性屈光参差的双眼视功能总体优于远视性屈光参差,但屈光参差与立体视的关系应按性质分别进行分析。

  11. Measurement of peripapillary retinal nerve fiber layer thickness and macular thickness in anisometropia using spectral domain optical coherence tomography: a prospective study

    Science.gov (United States)

    Singh, Neha; Rohatgi, Jolly; Gupta, Ved Prakash; Kumar, Vinod

    2017-01-01

    Purpose To study whether there is a difference in central macular thickness (CMT) and peripapillary retinal nerve fiber layer (RNFL) thickness between the two eyes of individuals having anisometropia >1 diopter (D) using spectral domain optical coherence tomography (OCT). Material and methods One hundred and one subjects, 31 with myopic anisometropia, 28 with astigmatic anisometropia, and 42 with hypermetropic anisometropia, were enrolled in the study. After informed consent, detailed ophthalmological examination was performed for every patient including cycloplegic refraction, best corrected visual acuity, slit lamp, and fundus examination. After routine ophthalmic examination peripapillary RNFL and CMT were measured using spectral domain OCT and the values of the two eyes were compared in the three types of anisometropia. Axial length was measured using an A Scan ultrasound biometer (Appa Scan-2000). Results The average age of subjects was 21.7±9.3 years. The mean anisometropia was 3.11±1.7 D in myopia; 2±0.99 D in astigmatism; and 3.68±1.85 D in hypermetropia. There was a statistically significant difference in axial length of the worse and better eye in both myopic and hypermetropic anisometropia (P=0.00). There was no significant difference between CMT of better and worse eyes in anisomyopia (P=0.79), anisohypermetropia (P=0.09), or anisoastigmatism (P=0.16). In anisohypermetropia only inferior quadrant RNFL was found to be significantly thicker (P=0.011) in eyes with greater refractive error. Conclusion There does not appear to be a significant difference in CMT and peripapillary RNFL thickness in anisomyopia and anisoastigmatism. However, in anisohypermetropia inferior quadrant RNFL was found to be significantly thicker. PMID:28260856

  12. Prevalence and association of refractive anisometropia with near work habits among young schoolchildren: The evidence from a population-based study

    Science.gov (United States)

    Lee, Chia-Wei; Fang, Shao-You; Huang, Nicole; Hsu, Chih-Chien; Chen, Shing-Yi; Chiu, Allen Wen-Hsiang

    2017-01-01

    Background Lifestyle behaviour may play a role in refractive error among children, but the association between near work habits and refractive anisometropia remains unclear. Methods We estimated the prevalence of refractive anisometropia and examined its association with near work activities among 23,114 children in the Myopia Investigation Study in Taipei who were grade 2 elementary school students at baseline in 2013 and 2014. Baseline data on demographics, medical history, parental history and near work habits were collected by parent-administered questionnaire survey. Refractive status was determined by cycloplegic autorefraction. Refractive anisometropia was defined as the spherical equivalent difference ≥ 1.0 diopter between eyes. Results The prevalence of refractive anisometropia was 5.3% (95% confidence interval [CI], 5.0% to 5.6%). The prevalence and severity of refractive anisometropia increased with both myopic and hyperopic refractive error. Multivariate logistic regression analysis revealed that refractive anisometropia was significantly associated with myopia (odds ratio [OR], 2.98; 95% CI, 2.53–3.51), hyperopia (OR, 2.37; 95% CI, 1.98–2.83), degree of astigmatism (OR, 1.005; 95% CI, 1.005–1.006), amblyopia (OR, 2.54; 95% CI, 2.06–3.12), male gender (OR, 0.88; 95% CI, 0.78–0.99) and senior high school level of maternal education (OR, 0.69; 95% CI, 0.52–0.92). Though anisometropic children were more likely to spend more time on near work (crude OR, 1.15; 95% CI, 1.02–1.29) and to have less eye-to-object distance in doing near work (crude OR, 1.15; 95% CI, 1.01–1.30), these associations became insignificant after additional adjustment for ocular, demographic and parental factors. Conclusions The present study provides large-scale, population-based evidence showing no independent association between refractive anisometropia and near work habits, though myopia is associated with refractive anisometropia. PMID:28273153

  13. Analysis of possible causes of anisometropia%屈光参差的可能原因分析

    Institute of Scientific and Technical Information of China (English)

    黄再红; 唐知进

    2016-01-01

    目的:研究不同类型屈光参差的流行病学特点及相关因素。方法:收治屈光参差患者316例,运用睫状肌麻痹剂散瞳检影验光,按照屈光参差的性质,分成远视组、近视组和异种组3组,调查表收集流行病学资料。结果:远视组73例(24.05%),发现视力异常的平均年龄6.15岁,每日近距离用眼时间>2 h(26.31%)。近视组197例(62.34%),发现视力异常的平均年龄8.07岁,每日近距离用眼时间>2 h(51.02%)。异种组46例(14.57%),发现视力异常的平均年龄6.03岁,每日近距离用眼时间>2 h者39.13%。结论:屈光参差主要与不良用眼习惯和阅读姿势有关。%Objective:To research the epidemiological characteristics and related factors of different types of anisometropia. Methods:316 patients with anisometropia were selected.Cycloplegic mydriasis retinoscopy optometry was applicated.According to the nature of anisometropia,they were divided into the hyperopic group,myopia group and heterogeneous group.Questionnaire was used to collect epidemiological data.Results:73 cases(24.05%) of hypermetropia group were found vision disorders,the average age of 6.15 years,and daily close eye time >2 h were 26.31%. 197 cases(62.34%) of myopia group were found that the average age of 8.07 years of age,the average age of 51.02% years,2 h per day.Heterogeneous group of 46 cases(14.57%) were found that the average age of visual acuity was 6.03 years old,and the daily close distance with eye time >2 h was 39.13%.Conclusion:The main anisometropia is related with bad habits with the eyes and reading posture.

  14. Corneal refractive surgery and phakic intraocular lens for treatment of amblyopia caused by high myopia or anisometropia in children

    Institute of Scientific and Technical Information of China (English)

    Tian Chunyu; Peng Xiujun; Fan Zhengjun; Yin Zhengqin

    2014-01-01

    Objective A systematic review of literature was performed to compare various visual function parameters including the final visual acuity outcome and/or adverse events between corneal refractive surgery (CLRS) and phakic intraocular lens implantation (p-IOLi) in the treatment of refractive amblyopic children.Data sources Two reviewers independently searched the PubMed,EMBASE,and Controlled Trials Register databases for publications from 1991 to 2013.Study selection There were 25 articles,including 597 patients and 682 eyes,was included in CLRS group.Among them,21 articles reported the use of CLRS in the treatment of myopic anisometropia for 318 patients (13 photorefractive keratectomy or laser epithelial keratomileusis and eight laser in situ keratomileusis).And 11 articles had the results of CLRS in treating hyperopic anisometropic amblyopia children.Eleven articles reported the effect of p-IOLi for treating high myopia or anisometropic amblyopia,including 61 patients (75 eyes).Age,pre-and postoperation best-corrected vision acuity (BCVA),and spherical equivalent (SE) were compared in CLRS and p-IOLi groups.Results The average age of CLRS group and p-IOLi group has no statistically significant difference.The SE in CLRS group for myopic anisometropia amblyopia patients was (-10.13±2.73) diopters (D) and for hyperopic anisometropia amblyopia patients was (5.58±1.28) D.In p-IOLi group the SE was (-14.01±1.93) D.BCVA was improved significantly in both groups,and even better in p-IOLi group.Refractive errors were corrected in both groups,but there was no clinically significant difference in final SE between each group.More than one-half of the children had improved binocular fusion and stereopsis function in both groups.Conclusions Both CLRS group and p-IOLi group showed their advantage in treating refractive amblyopia in children.In comparing p-IOLi with CLRS for treatment of refractive amblyopia,no statistically significant difference in final BCVA was observed.

  15. The therapeutic effects analysis on LASIK surgical correction of myopic and hyperopic anisometropia of visual function in patients%LASIK手术矫治屈光参差患者视功能的疗效分析

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    陈利; 杨红; 汪辉; 王科; 宋利兵

    2012-01-01

    目的 探讨LASIK手术治疗儿童屈光参差的疗效.方法 通过回顾性分析30例屈光参差患儿实施LASIK手术前与手术后不同时间视力、屈光度、眼轴、双眼视觉、VEP等视功能参数的变化,了解LASIK手术的疗效.结果 近视组手术后裸眼视力有明显提高(P0.05).两组手术前后眼轴无明显增长(P>0.05).结论 LASIK手术矫治儿童屈光参差,能降低高屈光度眼的屈光力、缩小双眼屈光度的差别,利于双眼融像.%Objective To investigate the efficacy of two sets of anisometropic in patients with LASIK surgery. Methods A retrospectively comparative analysis of the LASIK surgery correcting myopia and anisometropic in patients with postoperative visual function changes. Observe high diopter eyes of 15 cases with myopic anisometropia and 15 cases with hyperopic anisometropia after LASIK surgery preoperative and postoperative 1 year, 2 years, 3 years of visual acuity, and check the diopter ,axial length,binocular vision,and VEP. Results Myopia unconnected visual acuity was significantly improved( P 0. 05 ). The axial length of two groups did not significantly increase( P >0. 05 ). Conclusion LASIK surgery correction of children anisometropia can reduce the refractive power of the high-diopter eye, narrowed eyes diopter difference, which will help the eyes melt.

  16. 近视性屈光参差LASIK前后立体视觉的评价%Clinical investigation on the stereopsis of myopic anisometropia patients treated with laser in situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    吴章友; 潘红飙; 万川

    2008-01-01

    目的 用多种方法测准分子激光原位角膜磨镶术,矫治近视性屈光参差患者术前及术后远、近立体视觉,从视觉最高级形式的角度评价LASIK矫正近视性屈光参差患者的临床应用价值.方法 对112例近视性屈光参差患者,手术前和LASIK手术3个月后,采用颜氏随机点立体视觉检查图检查近立体视锐度、交叉视差、非交叉视差,Titmus立体视觉检查图、金贵昌双眼立体视觉检查图检查近立体视觉,同视机随机点立体图片检查远立体视觉.结果 LASIK术后3个月,91.9%患者裸眼远视力达到或超过术前最佳矫正视力.3种方法检查术后远、近立体视锐度均明显增进.立体视觉的增进显著,有统计学意义(P<0.05).结论 LASIK手术能重建、改善和促进立体视觉功能,有效地矫治屈光参差,手术安全、治疗效果肯定.%Objective With several methods, pre-and post-operative far and near stereopsis were tested in patients with myopic anisometropia undergone laser in situ keratomileusis (LASIK). So clinical effects of this treatment were evaluated at the highest level of vision function. Method 112 myopic anisometropia patients were enrolled in the research before the operation and 3 months after anisometropia were abolished by LASIK. Near stereopsis, crossed disparity and uncrossed disparity were measured by Yan's random-dot stereograms. Near stereopsis was also measured by Titmus stereograms and Jinguichang random-dot stereograms. Far stereopsis was measured by synoptophore. Results 3 months after LASIK, UCVAs of 91.9% patients were the same as or better than those of preoperative. Far and near stereopsis were improved obviously measured by all three methods. There is significant difference in the improvement of stercopsis. Conclusion With the treatment of myopic anisometropia by LASIK,most patients got much improvement in far and near stereopsis. LASIK could rebuild,improve and promote the stereopsis, and treat

  17. Effect of correcting myopic anisometropia by Ortho K contact lens on binocular vision%角膜塑形镜矫正近视性屈光参差对双眼视功能的影响

    Institute of Scientific and Technical Information of China (English)

    兰小川; 石春和

    2016-01-01

    •AIM: To analyze the effects on binocular vision after wearing Ortho K ( OK ) contact lens for myopic anisometropia.•METHODS:A total of 40 cases of myopic anisometropia corrected by Ortho K contact lens were collected. The average age of participants was 11. 32 ± 2. 56y. The refractive error varied from -1. 25D to -5. 75D, on average-3. 18±1. 12D. The amount of myopic anisometropia was-4. 64±1. 52D. All the cases were followed-up for 3mo. The uncorrected visual acuity ( UCVA ) , best corrected visual acuity ( BCVA ) , refraction and binocular vision were checked pre-wearing Ortho K contact lens, and 3mo post wearing respectively.•RESULTS:The mean UCVA was 4. 0±0. 2, and BCVA was 4. 96±0. 2, the amount of myopic anisometropia was -4. 64 ±1. 52D pre-wearing OK contact lens. The mean UCVA was 4. 97 ± 0. 07, and BCVA was 4. 99 ± 0. 1, the amount of myopic anisometropia was 0. 23 ± 0. 12D, at post wearing OK lens 3 months respectively. The UCVA, BCVA, the amount of myopic anisometropia at post correction was significantly difference with pre-correction (P vision, 7 cases with peripheral stereo vision, and 6 cases with stereo vision blind. Macular fovea stereo vision was found in 27 cases, Abnormal stereo vision existed in 13 cases, including 7 cases with macula stereo vision, 3 cases with peripheral stereo vision, and 3 cases with stereo vision blind after wearing Ortho K contact lens 3mo.•CONCLUSION:Most myopic anisometropia patients can improve their visual acuity, reduce the refractive difference, and increase combined and stereopsis vision after wearing Ortho K contact lens 3mo.%目的:观察近视性屈光参差患者配戴角膜塑形镜后双眼视功能的变化。方法:选取40例配戴角膜塑形镜的近视性屈光参差患者,观察配戴前和配戴3 mo 后裸眼视力( uncorrected visual acuity,UCVA)、最佳矫正视力( best corrected visual acuity, BCVA)、屈光参差度、同视机双眼视功能、近立体视功能的变化

  18. 学龄儿童握笔姿势与双眼屈光度差异的关系%Relationship between myopic anisometropia and writing hand position in school-aged children

    Institute of Scientific and Technical Information of China (English)

    夏承志; 刘庆淮

    2012-01-01

    Objective To study the relationship between writing strokes and myopic anisometropia in primary school-aged children.Methods It was a cross-sectional study.The refractive data of 100 primary school-aged children who held a pencil in the correct position was collected in the outpatient department of ophthalmology.In addition,the refractive data of another 100 primary school-aged children who held a pencil in an abnormal position was collected.All the screened children who tested for amblyopia,strabismus or astigmatism higher than 1.0 D were excluded from the study.The cycloplegic refractive status of all the screened children was checked and recorded.The difference between the two groups' refractive status was calculated and compared using a Wilcoxon rank sum test.Results Data analysis showed that the difference between the average degree of anisometropia between the two groups was statistically significant.The group with the abnormal writing hand position had a higher average degree of anisometropia than the group with the right writing strokes (Z=-10.33,P<0.01).And more right eyes had a higher degree of myopia than left eyes.Conclusion An abnormal writing hand position can be an important cause of school-aged children developing myopic anisometropia with right eyes often having a higher degree of myopia than left eyes.Further study is needed on this topic for clarification.%目的 通过临床观察儿童握笔姿势,探讨儿童不正确握笔与双眼近视性屈光度差异的相关性.方法 横断面研究.排除在南京市中西医结合医院眼科建立屈光档案的儿童中患弱视、斜视及散光大于1.0 D者,按男女比1:1随机抽取经确认握笔姿势正确和不正确的儿童各100例.通过睫状肌麻痹验光数据比较左右眼屈光度差值,以左眼等效球镜度减去右眼等效球镜度的代数值进行统计.对两组左右眼屈光度差值是否存在差异进行Wilcoxon秩和检验.结果 握笔错误组右眼近视度

  19. The Effect of Orthokeratology Lens for the Correction of Juvenile Myopia Anisometropia on Binocular Vision%角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响

    Institute of Scientific and Technical Information of China (English)

    纪冬梅

    2016-01-01

    目的:探讨角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响。方法对在我院接受角膜塑形治疗的32例(50只眼)近视性屈光参差患者的临床资料进行回顾分析,比较患者治疗前后裸眼视力屈光参差度以及屈光度等的变化。结果治疗1年后裸眼视力达到或超过治疗前最佳矫正视力1.0以上45只眼,占90.0%。治疗前后患者屈光参差度分别为(3.12±1.21)D和(0.35±0.37)D,治疗前后差异有统计学意义(P<0.05)。治疗后近视加深速度与治疗前比较有所减缓。结论青少年近视性屈光参差患者接受角膜塑形治疗可有效改善患者双眼视觉功能。%Objective To investigate the influence of orthokeratology lens in correction of juvenile myopia anisometropia on binocular vision.Methods In our hospital accepted clinical data of orthokeratology treatment of 32 cases(50 eyes)with myopia refractive anisometropia patients who were retrospectively analyzed,compared before and after treatment in patients with naked eye visual acuity of anisometropia and refraction changes.ResultsAfter 1 years of treatment,the visual acuity reached or exceeded 45 of the best corrected visual acuity before treatment 1 years later,the proportion was 90.0%. Before and after treatment in patients with anisometropia were(3.12±1.21)D and(0.35±0.37)D,there were significant differences before and after the treatment(P<0.05). After the treatment,the rate of myopia deepening was somewhat slower than before treatment.Conclusion Juvenile myopia anisometropia patients undergoing orthokeratology therapy can effectively improve the patients with binocular visual function.

  20. Clinical study on rigid gas permeable lenses decreasing the children's anisometropia caused by hyperopia%高透氧硬性角膜接触镜减少儿童远视屈光不等差异的疗效

    Institute of Scientific and Technical Information of China (English)

    唐云户; 赵媛

    2016-01-01

    目的:探讨在非弱视性远视屈光不等儿童中,使用高透氧硬性角膜接触镜( rigid gas permeable lens,RGP)矫正高屈光度眼视力,对双眼屈光度等效球镜差值(△SE )、眼轴差值(△AL )的影响。方法:选择我院视光门诊远视性屈光不正的6~12岁儿童95例190眼,且双眼屈光度差值(△SE)1D≤△SE<2.0D和矫正视力不等,但每一眼的矫正视力均在同龄儿童正常范围内,即均非弱视。随机分为两组:A组48例,给屈光度较高眼(视力较差眼)配戴RGP,另一眼不戴镜处理;B组47例,不配镜作为对照组。用1%环戊酮散瞳验光计算等效球镜(SE),测量眼轴(AL),并随访1.5a。分别计算A组和B组等效球镜差值(△SE )、眼轴差值(△AL ),进行统计学分析。结果:A组双眼之间等效球镜度差值(△SE )小于B组,差异有统计学意义(F=18.508,P=0.002<0.05);A组双眼之间眼轴差值(△AL )小于B组,差异有统计学意义( F=1116.765,P=0.000<0.05)。结论:在非弱视性远视屈光不等儿童中,用RGP矫正高屈光度眼视力是有必要的,可以明显减少双眼屈光度、矫正视力差异,避免屈光参差所带来的视觉功能异常等一系列问题。%Abstract•AIM:To investigate the effect of rigid gas permeable lenses ( RGP ) for the difference of spherical equivalent (△SE ) and the difference of axial length (△AL ) in children with non-amblyopia anisometropia.•METHODS:In department of optometry in our hospital, 95 children 190 eyes aged from 6 ~12 year-old with hyperopic refractive error, of whom the difference of spherical equivalent between two eyes was 1D≤△SE <2.0D and whose corrected vision was different, but the corrected visual acuity of either right eye or left eye was within the normal range of children with the same age, which meant the difference was non

  1. Clinal effects of LASIK on binocular vision in myopic anisometropia%近视性屈光参差患者LASIK术后双眼视功能评估

    Institute of Scientific and Technical Information of China (English)

    杨亮; 胡琦; 康杨; 黄磊; 王珂萌

    2012-01-01

    目的 观察近视性屈光参差患者接受准分子激光原位角膜磨镶术( LASIK)后双眼视功能的变化,探讨LASIK手术矫治近视性屈光参差对三级视功能的影响,从双眼视觉的变化评价其临床应用价值.设计前瞻性病例系列.研究对象36例(72眼)行LASIK手术的近视性屈光参差患者(双眼屈光参差≥2.50 D).方法 对36例行LASIK手术的近视性屈光参差患者分别于手术前和手术后3个月进行裸眼视力、最佳矫正视力、屈光状态和同视机双眼视功能的检测,并对双眼视功能的变化进行随访研究.主要指标手术前后裸眼视力、最佳矫正视力、屈光度、同时视、融合功能、远立体视和近立体视.结果 术前72眼的裸跟视力在0.01-0.2之间,术后3个月时均达到1.0.双跟屈光参差由术前的(5.01±1.96)D( 2.50~9.00 D),降低到术后3个月的( 0.28±0.22 )D(0.00~0.75 D).手术前后的屈光参差度的改变,差异均有显著统计学意义(P<0.01).26例屈光参差量≥2.50 D且≤6.00 D的高度屈光参差者术前戴框架眼镜下近立体视正常的12例,术后3个月增至22例,差异有统计学意义(P<0.05);16例屈光参差量>6.0D的重度屈光参差者手术前后均没有正常近立体视.术前戴框架眼镜下三级视功能(同时视、融合功能、远立体视)正常的分别为33例、18例、13例,LASIK术后3个月三级视功能正常的分别为34例、33例、23例,手术后获得融合功能和远立体视者较术前明显增加(P均<0.05).结论 LASIK矫治近视性屈光参差,不仅可提高患者裸眼视力,而且可通过减小患者双眼间的屈光差异,增加双眼物像的融合,改善立体视功能.%Objective To analyze the clinical effects on binocular vision after LASIK for myopic anisomelropia, and evaluate its clinical value in the view of vision quality. Design Prospective case series. Participants 36 cases (72 eyes) with myopic anisometropia who received

  2. 角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响%Research on binocular vision after wearing orthoker-atology lens in adolescent myopic anisometropia

    Institute of Scientific and Technical Information of China (English)

    张春侠; 李自芳; 陈梅珠

    2015-01-01

    Objective To analyze the binocular vision after wearing orthokeratology lens in adolescent myopic anisometropia.Methods Twenty-three patients of retrospective cases with binocular myopic anisometropia more than 2.50 diopters received orthokeratology lens.All patients were followed 12-50 months,to observe the uncorrected visual acuity (UCVA),best-spectacles corrected visual acuity (BSCVA),refraction,binocular vision before and after wearing orthokeratology lens.Results The uncorrected visual acuity was improved significantly,the BCVA of 31 eyes (86.0%) reached or more than BSCVA.In the degree of anisometropia,there was a significant difference between before treatment (3.08±l.42)D and post-treatment (0.36±0.40)D.The myopia degree increased (0.22±0.38)D in high degree myopic eye after one year treatment,(0.16±0.30)D in low degree myopic eye.The short distance stereopsis vision after wearing orthokeratology lens was significantly higher than that before treatment (x2=27.22,P <0.01).And it was also significantly higher than that before treatment with corrected glasses (x2=15.51,P <0.01).Conclusions Orthokeratology lens can improve the UCVA,control the development of myopia and resume the binocular vision for adolescent myopic anisometropia.%目的 探讨角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响及临床价值.方法 回顾性临床分析研究.对2009年10月至2013年4月在南京军区福州总医院接受角膜塑形镜治疗,资料完整的23例(36只眼)屈光参差患者,持续戴镜12~50个月进行随访,观察治疗前及配戴角膜塑形镜裸眼视力(UCVA)、最佳矫正视力(BSCVA),屈光度数变化及双眼视觉.结果 配戴角膜塑形镜1年时裸眼视力(UCVA)达到或超过治疗前最佳矫正视力(BSCVA)的百分比为:86% (31/36).治疗前双眼屈光参差度数为(3.08±1.42)D,配戴角膜塑形镜为(0.36±0.40)D,较治疗前明显降低.配戴角膜塑形镜近视加深度数1

  3. The effect of recovering stereoscopic vision of anisometropia people with glasses%框架眼镜矫正成人高度屈光参差立体视重建的分析

    Institute of Scientific and Technical Information of China (English)

    孙凤珍; 杨积文; 郭如汾

    2012-01-01

    目的 观察成人高度屈光参差经框架眼镜矫正后两眼立体视重建的效果.方法 以2010年1月至2011年3月就诊视光中心进行验光配镜的高度屈光参差,并戴镜后可完全耐受的69例患者为对象,年龄20~45岁.经眼部检查,无斜视及眼部其它疾病,矫正后双眼视力均为1.0.屈光参差范围球镜:4.00~5.50 DS之间,柱镜范围:0.50~1.00 DC,综合验光仪检查虽然有感觉融像但没有立体视觉.戴镜后1个月、3个月、6个月复查.结果 戴镜1个月时,立体视重建患者33例占47.8%,3个月时,立体视重建患者48例占69.6%,6个月时立体视重建患者57例占82.6%,经统计学分析,x2值分别为67.97、70.57、93.73,均P<0.05,差异有统计学意义.结论 对于2.50 D以上的屈光参差在患者耐受的情况下应积极进行完全矫正,矫正后因各眼所见图像的空间频率相同时可有最佳视力,使双眼视得以重建.框架眼镜矫正屈光参差对立体视的重建有着重要的临床意义.%Objective To investigate the effect of stereoscopic vision of anisometropia people with glasses in clinical practice. Methods Sixty-nine nisometropia patients were fitted with glasses,those patients had no any eye diseases and stereoscopic vision.The period of follow-up ranged 1month,3 months,and 6 months to observe the changing of stereoscopic vision. Results After 1month,33 patients had stereoscopic vision; after 3 months,48 patients had stereoscopic vision; after 6 months 57 patients had stereoscopic vision.The difference was statistically significant (P <0.05).Conclusions Anisometropia patients are better to have glasses to help recover stereoscopic vision.

  4. 屈光参差性弱视儿童色觉中枢激活范围的 BOLD-fMRI初步研究%Visual cortex activation range of color vision with BOLD-fMRI in anisometropia amblyopia children

    Institute of Scientific and Technical Information of China (English)

    张惠芳; 燕振国

    2014-01-01

    AIM:To analyze the recovery of visual cortex activation range of color vision in anisometropia amblyopia children after treatment by using blood oxygen level dependence-functional magnetic resonance imaging ( BOLD- fMRI ) and SPM8 software. METHODS:Self-control study. This fMRI study directly compared activity in visual cortex produced by color monocular stimulation in 13 monocular anisometropia amblyopia children. The project of study was blocked design. The data of functions and anatomical MRI was stimulated by three-primary colors and was preprocessed and analyzed by SPM8 that based on MATLAB software. According to the data, we compared the change of the central area of color vision when first visit and 1, 2 ,4wk after treatment. RESULTS: The BA17, BA18, BA19 and BA37 of amblyopia children were different activated after they accepted the three-primary colors stimulation (P CONCLUSION: After 4wk treatment, visual cortex activation of color vision of anisometropia amblyopic children is expanded, but with low extent, after the short-term treatment of amblyopia, visual cortex activation of color vision has a certain degree of recovery but not obvious.%目的:利用血氧水平依赖性功能磁共振成像( blood oxygen level dependence-functional magnetic resonance imaging, BOLD-fMRI)及SPM8软件研究分析经过系统治疗后屈光参差性弱视儿童色觉中枢激活区域的恢复情况。  方法:自身前后对照研究。利用3.0T超导磁共振采集13例屈光参差性弱视儿童色觉中枢激活区域的试验数据,采用组块设计方案,以三原色作为刺激源获取色觉皮层激活区功能核磁共振数据,应用基于MATLAB 软件下的运行的SPM8对数据进行预处理及分析,对比初诊、治疗1,2,4 wk后色觉中枢激活区域的变化。  结果:弱视初诊患儿接受三原色刺激后, BA17, BA18, BA19,BA37均有不同范围的激活(P  结论:经过4 wk的系统治疗后屈光参差性弱视儿童

  5. Cliuical effecfive of LASIK for hyperopic ~anisometropia in adoleacent%青少年远视屈光参差性弱视LASIK效果观察

    Institute of Scientific and Technical Information of China (English)

    张芬萍; 马红霞; 李晓林

    2011-01-01

    Objective To investigate efficacy and safety of LASIK for hyperopic anisometropic amblyopia in adolescent. Methods 56 Cases (9 - 17 years old) of hyperopic anisometropic amblyopia were involved in the clinical study. The mean corrected visual acuity was 0. 38 ± 0. 09 ; routine perioperative examination was performed. All the patients were accepted birocular vision training and treatment of amblyopia. Results The poatoperative uncorrected visual acuity in 3 months was 0. 65 ± 0. 15 compared 0. 07 ±0.03 preoperatively,and was 0. 68 ±0. 14 in 6 months postoperatively. Postoperative refractionsignificantly decreased ( P <0.05 ). 52 patients improved binocular vision, and 36 patients establish complete stereopsis. Conclusion LASIK for hyperopic anisometropic amblyopia is safe and effective in adolescent. It could improve binocular vision.%目的 探讨准分子激光原位角膜磨镶术( LASIK)矫治青少年重度远视屈光参差性弱视的效果与安全性。方法 56例(56眼)平均矫正视力为0.38±0.09的9~17岁远视屈光参差性弱视纳入观察,常规行围手术期检查。术后进行双眼训练和弱视治疗。结果 术后3个月弱视眼平均裸眼视力由术前的0.07±0.03提高到0.65 ±0.15;术后6个月平均裸眼视力为0.68±0.14。术后矫正视力较术前明显提高;术后屈光度较术前明显降低(P<0.05);52例(92.86%)同时视和融合功能改善,其中36例(64.29%)建立完整立体视功能。结论 青少年远视屈光参差性弱视的LASIK安全有效,有助于改善双眼单视功能。

  6. Effects of defocus and aniseikonia by anisometropia on stereoacuity%实验性屈光参差产生的视网膜像模糊和不等像视对立体视影响的研究

    Institute of Scientific and Technical Information of China (English)

    徐进; 胡聪

    2004-01-01

    目的研究实验性屈光参差及其造成的视网膜像模糊和不等像视对立体视的影响.方法在正常眼前放置正、负球镜,人工诱导单纯性远视、近视性屈光参差.自制在同视机分视下的,由双屏显示的计算机立体视及不等像视检查,分别分析实验性屈光参差产生的视网膜像模糊和不等像视各因素对立体视的影响.结果不等像视达到8%时,立体视锐度开始迅速降低.实验性屈光参差和视网膜像模糊在各参差度比较中均无显著差异.结论(1)当不等像低于8%时对立体视检查结果的影响并不大.(2)实验性屈光参差产生的视网膜像模糊是影响立体视的主要因素.(3)在屈光参差性弱视的治疗中,应尽可能矫正屈光不正,使患者视网膜能得到清晰的像,同时应注意不等像视的影响,将配镜后的不等像视控制在8%以内.

  7. Analysis of balance of binocular vision after successful treatment in anisometropia amblyopic children%屈光参差性弱视儿童治疗后双眼视觉输入平衡分析

    Institute of Scientific and Technical Information of China (English)

    黄杰; 叶翔; 李国平; 吕冬蕾; 赵晴; 温莹

    2016-01-01

    目的 探讨轻、中度屈光参差性弱视儿童经屈光矫正合并遮盖治疗弱视眼的视锐度恢复到相应正常水平后,双眼视觉输入是否达到平衡状态.方法 选择成功治疗半年以上,视锐度恢复到相对稳定状态的轻、中度屈光参差性弱视儿童为弱视治疗组(n=15).正常对照组选择相应年龄段的正常儿童(n=15).受试者配戴立体眼镜,通过阈上双眼相位结合的方法对其进行双眼相互作用的检测.所有试验信息由计算机系统自动记录,最终进行模型分析得到双眼的有效对比度比,将其作为评价双眼视觉输入平衡的主要指标.结果 弱视治疗组治疗后弱眼和强眼的视锐度分别为(-0.02±0.06)logMAR和(-0.05±0.05)logMAR,弱视治疗后双眼的视锐度差异无统计学意义(P>0.05).与正常对照组相比,经屈光矫正合并遮盖治疗后,虽然屈光参差性弱视儿童弱眼的视锐度得到了较好的恢复,但是其双眼视觉输入依然不平衡.弱视治疗组弱眼的有效对比度比为0.27 ±0.09,正常对照组的有效对比度比为(0.95±0.07).与正常对照组相比,弱视治疗组弱眼的平均有效对比度比降低了72%,差异有显著统计学意义(P <0.001).结论 经屈光矫正合并遮盖治疗视锐度恢复正常后的轻、中度屈光参差性弱视儿童,双眼输入的信号强度依然是不平衡的,双眼视觉功能依然存在缺陷.这种双眼输入信号强度的不平衡可能是儿童弱视易复发的一个潜在因素.

  8. [Difficulties of diagnosis in a case of optic nerve drusen].

    Science.gov (United States)

    Munteanu, M; Munteanu, G

    2000-01-01

    This paper presents a particullary case of optic nervue drusen. Ophthalmoscopic features (superficial drusen in one eye and deep drusen in another), clinical association with anisometropia and ambliopia, wrong interpretation of PEV and tomodensitometry mod to diagnostic confusion, supplementary investigations, prolonged and expensive treatment.

  9. [Study and application of "binocular aniseikonia test chart"].

    Science.gov (United States)

    Liu, A N; Yan, S M

    1994-09-01

    With the help of this chart, the image incongruity of simultaneous perception, fusion and stereoscopic vision can be precisely determined. It can objectively evaluate the binocular visual function and possesses important significance for the diagnosis and treatment of anisometropia, amblyopia, strabismus and visual fatigue.

  10. The Importance of the Relationship Between The Position of the Correcting Lens Principal Planes (H'1-H'2) and Principal Planes (H1-H2) of the Optical Eye System – Aphakic Correction

    OpenAIRE

    Vojniković, Božo; Njirić, Sanja

    2013-01-01

    In the clinical refraction of the eye, aniseikonia and anisometropia are inevitably used terms. Image formation and its retinal size is the function of the power of the dioptric eye system. However, the correcting lens in front of the eye and the eye optical system represent a unique optical afocal system, in which the distance between correcting lens and corneal vertex is of utmost importance, since it determines the size (together with appropriate correcting lens) of the retinal image. In t...

  11. Prevalence of amblyopia and refractive errors among primary school children

    Directory of Open Access Journals (Sweden)

    Zhale Rajavi

    2015-01-01

    Results: Amblyopia was present in 2.3% (95% CI: 1.8% to 2.9% of participants with no difference between the genders. Amblyopic subjects were significantly younger than non-amblyopic children (P=0.004. Overall, 15.9% of hyperopic and 5.9% of myopic cases had amblyopia. The prevalence of hyperopia ≥+2.00D, myopia ≤-0.50D, astigmatism ≥0.75D, and anisometropia (≥1.00D was 3.5%, 4.9%, 22.6%, and 3.9%, respectively. With increasing age, the prevalence of myopia increased (P<0.001, that of hyperopia decreased (P=0.007, but astigmatism showed no change. Strabismus was found in 2.3% of cases. Strabismus (OR=17.9 and refractive errors, especially anisometropia (OR=12.87 and hyperopia (OR=11.87, were important amblyogenic risk factors. Conclusion: The high prevalence of amblyopia in our subjects in comparison to developed countries reveals the necessity of timely and sensitive screening methods. Due to the high prevalence of amblyopia among children with refractive errors, particularly high hyperopia and anisometropia, provision of glasses should be specifically attended by parents and supported by the Ministry of Health and insurance organizations.

  12. Três anos pós-LASIK em crianças anisométropes de 8 a 15 anos de idade Three years after LASIK in anisometropic children from 8 to 15 years old

    Directory of Open Access Journals (Sweden)

    Belquiz R. Amaral Nassaralla

    2003-01-01

    Full Text Available OBJETIVO: Determinar a segurança, eficácia, previsibilidade e estabilidade da técnica "laser in situ keratomileusis" (LASIK, três anos após a cirurgia, para a correção de alta anisometropia em crianças, para as quais os tratamentos convencionais não obtiveram êxito. MÉTODOS: Nove olhos de nove pacientes, três meninos e 6 meninas, com idade média de 11,5 anos (variando de 8 a 15 anos, foram submetidos à técnica LASIK utilizando-se o excimer laser Chiron Technolas 217. O tempo mínimo de seguimento foi de 36 meses. RESULTADOS: Três anos após o LASIK, a acuidade visual sem correção (AVSC melhorou pelo menos 5 linhas em todos os olhos; cinco olhos (55,5% apresentavam AVSC de 20/50 ou melhor. Seis olhos (66,6%, apresentavam acuidade visual com correção (AVCC de 20/50 ou melhor e cinco olhos (55,5% ganharam pelo menos 1 linha na AVCC. Devido a ambliopia, nenhum olho apresentou AVSC de 20/20 ou melhor. A média do equivalente esférico pré-operatório foi reduzida de -7,66 (± 3,75 D para -1,02 (± 1,26 D e a do astigmatismo, de -3,11 (± 2,09 D para -0,75 (± 0,25 D. A maior anisometropia encontrada foi de 1,5 D. CONCLUSÕES: Após três anos de seguimento, a técnica LASIK parece ser opção segura e eficaz na correção de alta anisometropia em crianças entre 8 e 15 anos de idade, para os quais os tratamentos convencionais não obtiveram êxito. A progressão do erro refracional relacionada à idade não impediu o uso da correção visual adequada.PURPOSE: To determine the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK, three years after surgery, to correct high myopia or high myopic astigmatism in children with high anisometropia in whom conventional treatments had failed. METHODS: Nine eyes of 9 patients, 3 boys and 6 girls with a mean age of 11.5 years (range, 8 to 15 years underwent LASIK using the Chiron Technolas 217 excimer laser. Minimum follow-up was 36 months. RESULTS: Three

  13. Associação entre hiperopia e outros erros refrativos e visuais em crianças

    Directory of Open Access Journals (Sweden)

    Merry Elizabeth Goedert

    2016-02-01

    Full Text Available RESUMO Objetivo: Investigar a associação da hipermetropia com ambliopia, estrabismo, anisometropia e astigmatismo. Métodos: A hiperopia foi classificada em Grupo 1: maior ou igual a +5.00D; Grupo 2: maior que +3.25D e menor que +5.00D, com diferença de equivalente esférico maior ou igual a 0.50D; Grupo 3: maior que +3.25D e menor que +5.00D, com diferença de equivalente esférico menor que 0.50D e Grupo 4: com equivalente esférico maior e igual a +2.00D. O Grupo controle pertencente ao equivalente esférico menor que +2.00D. Resultados: A presença de hipermetropia maior e igual a SE+2.00D foi significativamente associada à maior proporção de crianças com ambliopia (27,2 vs. 14,8%, OR = 2,150, p<0,001 e estrabismo (70,8 vs. 39,3%, OR = 3,758, p<0,0001. A presença de hipermetropia também foi significativamente associada à maior proporção de anisometropia nos grupos com hipermetropia maior e igual a SE+2.00 (29,1 vs. 9,9%, OR = 3,708, p<0,0001 e astigmatismo (24 vs. 9,9%, OR = 2,859 p<0,0001. Conclusão: A presença e magnitude da hipermetropia entre crianças foram associadas à maior proporção de erros refrativos e visuais, como estrabismo, ambliopia, astigmatismo e anisometropia.

  14. A morphological study of retinal changes in unilateral amblyopia using optical coherence tomography image segmentation.

    Directory of Open Access Journals (Sweden)

    Andrea Szigeti

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the possible structural changes of the macula in patients with unilateral amblyopia using optical coherence tomography (OCT image segmentation. PATIENTS AND METHODS: 38 consecutive patients (16 male; mean age 32.4±17.6 years; range 6-67 years with unilateral amblyopia were involved in this study. OCT examinations were performed with a time-domain OCT device, and a custom-built OCT image analysis software (OCTRIMA was used for OCT image segmentation. The axial length (AL was measured by a LenStar LS 900 device. Macular layer thickness, AL and manifest spherical equivalent refraction (MRSE of the amblyopic eye were compared to that of the fellow eye. We studied if the type of amblyopia (strabismus without anisometropia, anisometropia without strabismus, strabismus with anisometropia had any influence on macular layer thickness values. RESULTS: There was significant difference between the amblyopic and fellow eyes in MRSE and AL in all subgroups. Comparing the amblyopic and fellow eyes, we found a statistically significant difference only in the thickness of the outer nuclear layer in the central region using linear mixed model analysis keeping AL and age under control (p = 0.032. There was no significant difference in interocular difference in the thickness of any macular layers between the subgroups with one-way between-groups ANCOVA while statistically controlling for interocular difference in AL and age. CONCLUSIONS: According to our results there are subtle changes in amblyopic eyes affecting the outer nuclear layer of the fovea suggesting the possible involvement of the photoreceptors. However, further studies are warranted to support this hypothesis.

  15. Contemporary management of aniseikonia.

    Science.gov (United States)

    Achiron, L R; Witkin, N; Primo, S; Broocker, G

    1997-01-01

    The diagnosis and management of aniseikonia has become a lost art. Refractive surgery and intraocular lens implantation has created a new patient population of anisometropia. Measurement of aniseikonia through instrumentation such as the space eikonometer is not readily available. Therefore, estimating the degree of aniseikonia based on the dioptral differences between the two eyes may be the most practical approach. The optical principles of spectacle magnification can be translated by the prescribing eye doctor to reduce ocular image disparity. Contemporary lens designs, such as hi-index and aspherics, allow the practitioner to modify shape and power factors to achieve higher levels of aniseikonic correction in a cosmetically fashionable pair of spectacles.

  16. Validity and repeatability of a new test for aniseikonia

    OpenAIRE

    Antona Peñalba, Beatriz; Barra Lázaro, Francisco; Barrio de Santos, Ana Rosa; González Díaz-Obregón, Enrique; Sánchez Pérez, Isabel

    2007-01-01

    PURPOSE. The Aniseikonia Inspector 1.1 (AI) is a new software product to measure aniseikonia using red-green anaglyphs. The purpose of this study was to test whether the AI is a valid and reliable test. METHODS. There were two groups of sample subjects: one at risk of aniseikonia, with anisometropia greater than or equal to 1.00 D (n = 29), and a control group (n = 45). The validity was studied by comparing the measured aniseikonia with the aniseikonia simulated with size lenses. The reli...

  17. Residual aniseikonia among patients fitted with one or two intraocular lenses (pseudophakic corrections)

    Science.gov (United States)

    Lakshminarayanan, V; Enoch, J M; Knowles, R A

    1993-02-01

    In the presence of one or two intraocular lenses (IOL's; pseudophakic corrections) or in the presence of naturally occurring or developmental anisometropia (due to a tumescent cataract) some induced or residual refractive aniseikonia is usually encountered. We wish to call this problem to the attention of the optometric practitioner. We provide a discussion of the resultant aniseikonia and simple rules of thumb for management of such patients with refractive aniseikonia. Aniseikonia in these patients may be less important than once had been suggested, but certainly it is more significant than it is currently being considered. Use of personal computers to calculate this aniseikonia makes appropriate correction relatively easy and readily applicable.

  18. The control of aniseikonia after intraocular lens implantation.

    Science.gov (United States)

    Hillman, J S; Hawkswell, A

    1985-01-01

    This paper reports a study of postoperative refraction and eikonometry of 50 patients who had unilateral cataract extraction with implantation of a pupil-supported intraocular lens. The mean postoperative aniseikonia (+/- SD) was 1.97 (+/- 1.82). A statistically significant relationship was shown between anisometropia and aniseikonia. Despite aniseikonia of up to 7.8 per cent there were no diplopia problems as the visual system exhibits a high degree of tolerance. It is concluded that aniseikonia can be controlled to within clinically acceptable limits by the simple calculation of intraocular lens power for isometropia.

  19. Eleven-year Experience with Radial Keratotomy

    Institute of Scientific and Technical Information of China (English)

    Akira; Momose

    1994-01-01

    1 900 consecutive eyes that underwent radial keratotomy by the senior author were evaluated retrospectively. 3 months after surgery, minimum reduction in mean spherical equivalent of 0. 67D was achieved with 1 incision and maximum 7. 250 with 24 incisions. Unconnected visual acuity of 20/40 or better was obtained in 99. 4% of eyes with low myopia, 64. 2% with moderate myopia and 32. 4% with high myopia. For anisometropia, bilateral RK reduced refractive error from -12. 12D to -5. 22D in more myopic eyes...

  20. Paediatric cataract: challenges and complications

    Directory of Open Access Journals (Sweden)

    Dr P Vijayalakshmi

    2016-10-01

    Full Text Available Amblyopia should always be anticipated in children with unilateral cataract, asymmetrical bilateral cataracts (or where there is a delay between the first and second eye operation, or a delay of more than a year between diagnosis/ detection and surgery, cataracts with anisometropia or traumatic cataracts with corneal scars. When amblyopia is detected, occlusion therapy (eye patching must be instituted at the earliest opportunity. The patching regimen is the same with any strabismic amblyopia and sometimes needs to be aggressive at the start. It is crucial to explain the need for patching to the parents, since compliance is the greatest obstacle to the success of amblyopia treatment.

  1. Immediate Sequential Bilateral Cataract Surgery: A Systematic Review and Meta-Analysis

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    Line Kessel

    2015-01-01

    Full Text Available The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation. We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery on two different dates. The quality of evidence was rated as low to very low. None of the studies reported the prevalence of postoperative anisometropia. In conclusion, we cannot provide evidence-based recommendations on the use of ISBCS due to the lack of high quality evidence. Therefore, the decision to perform ISBCS should be taken after careful discussion between the surgeon and the patient.

  2. Artificial Intelligence Techniques for Automatic Screening of Amblyogenic Factors

    Science.gov (United States)

    Van Eenwyk, Jonathan; Agah, Arvin; Giangiacomo, Joseph; Cibis, Gerhard

    2008-01-01

    Purpose To develop a low-cost automated video system to effectively screen children aged 6 months to 6 years for amblyogenic factors. Methods In 1994 one of the authors (G.C.) described video vision development assessment, a digitizable analog video-based system combining Brückner pupil red reflex imaging and eccentric photorefraction to screen young children for amblyogenic factors. The images were analyzed manually with this system. We automated the capture of digital video frames and pupil images and applied computer vision and artificial intelligence to analyze and interpret results. The artificial intelligence systems were evaluated by a tenfold testing method. Results The best system was the decision tree learning approach, which had an accuracy of 77%, compared to the “gold standard” specialist examination with a “refer/do not refer” decision. Criteria for referral were strabismus, including microtropia, and refractive errors and anisometropia considered to be amblyogenic. Eighty-two percent of strabismic individuals were correctly identified. High refractive errors were also correctly identified and referred 90% of the time, as well as significant anisometropia. The program was less correct in identifying more moderate refractive errors, below +5 and less than −7. Conclusions Although we are pursuing a variety of avenues to improve the accuracy of the automated analysis, the program in its present form provides acceptable cost benefits for detecting ambylogenic factors in children aged 6 months to 6 years. PMID:19277222

  3. The role of sensory ocular dominance on through-focus visual performance in monovision presbyopia corrections.

    Science.gov (United States)

    Zheleznyak, Len; Alarcon, Aixa; Dieter, Kevin C; Tadin, Duje; Yoon, Geunyoung

    2015-01-01

    Monovision presbyopia interventions exploit the binocular nature of the visual system by independently manipulating the optical properties of the two eyes. It is unclear, however, how individual variations in ocular dominance affect visual function in monovision corrections. Here, we examined the impact of sensory ocular dominance on visual performance in both traditional and modified monovision presbyopic corrections. We recently developed a binocular adaptive optics vision simulator to correct subjects' native aberrations and induce either modified monovision (1.5 D anisometropia, spherical aberration of +0.1 and -0.4 μm in distance and near eyes, respectively, over 4 mm pupils) or traditional monovision (1.5 D anisometropia). To quantify both the sign and the degree of ocular dominance, we utilized binocular rivalry to estimate stimulus contrast ratios that yield balanced dominance durations for the two eyes. Through-focus visual acuity and contrast sensitivity were measured under two conditions: (a) assigning dominant and nondominant eye to distance and near, respectively, and (b) vice versa. The results revealed that through-focus visual acuity was unaffected by ocular dominance. Contrast sensitivity, however, was significantly improved when the dominant eye coincided with superior optical quality. We hypothesize that a potential mechanism behind this observation is an interaction between ocular dominance and binocular contrast summation, and thus, assignment of the dominant eye to distance or near may be an important factor to optimize contrast threshold performance at different object distances in both modified and traditional monovision.

  4. Acuity-independent effects of visual deprivation on human visual cortex.

    Science.gov (United States)

    Hou, Chuan; Pettet, Mark W; Norcia, Anthony M

    2014-07-29

    Visual development depends on sensory input during an early developmental critical period. Deviation of the pointing direction of the two eyes (strabismus) or chronic optical blur (anisometropia) separately and together can disrupt the formation of normal binocular interactions and the development of spatial processing, leading to a loss of stereopsis and visual acuity known as amblyopia. To shed new light on how these two different forms of visual deprivation affect the development of visual cortex, we used event-related potentials (ERPs) to study the temporal evolution of visual responses in patients who had experienced either strabismus or anisometropia early in life. To make a specific statement about the locus of deprivation effects, we took advantage of a stimulation paradigm in which we could measure deprivation effects that arise either before or after a configuration-specific response to illusory contours (ICs). Extraction of ICs is known to first occur in extrastriate visual areas. Our ERP measurements indicate that deprivation via strabismus affects both the early part of the evoked response that occurs before ICs are formed as well as the later IC-selective response. Importantly, these effects are found in the normal-acuity nonamblyopic eyes of strabismic amblyopes and in both eyes of strabismic patients without amblyopia. The nonamblyopic eyes of anisometropic amblyopes, by contrast, are normal. Our results indicate that beyond the well-known effects of strabismus on the development of normal binocularity, it also affects the early stages of monocular feature processing in an acuity-independent fashion.

  5. Bilateral symmetry in vision and influence of ocular surgical procedures on binocular vision: A topical review.

    Science.gov (United States)

    Arba Mosquera, Samuel; Verma, Shwetabh

    2016-01-01

    We analyze the role of bilateral symmetry in enhancing binocular visual ability in human eyes, and further explore how efficiently bilateral symmetry is preserved in different ocular surgical procedures. The inclusion criterion for this review was strict relevance to the clinical questions under research. Enantiomorphism has been reported in lower order aberrations, higher order aberrations and cone directionality. When contrast differs in the two eyes, binocular acuity is better than monocular acuity of the eye that receives higher contrast. Anisometropia has an uncommon occurrence in large populations. Anisometropia seen in infancy and childhood is transitory and of little consequence for the visual acuity. Binocular summation of contrast signals declines with age, independent of inter-ocular differences. The symmetric associations between the right and left eye could be explained by the symmetry in pupil offset and visual axis which is always nasal in both eyes. Binocular summation mitigates poor visual performance under low luminance conditions and strong inter-ocular disparity detrimentally affects binocular summation. Considerable symmetry of response exists in fellow eyes of patients undergoing myopic PRK and LASIK, however the method to determine whether or not symmetry is maintained consist of comparing individual terms in a variety of ad hoc ways both before and after the refractive surgery, ignoring the fact that retinal image quality for any individual is based on the sum of all terms. The analysis of bilateral symmetry should be related to the patients' binocular vision status. The role of aberrations in monocular and binocular vision needs further investigation.

  6. Achados oculares em crianças de zero a seis anos de idade, residentes na cidade de São Caetano do Sul, SP Ocular findings in children between 0 and 6 years of age, residing in the city of São Caetano do Sul, SP

    Directory of Open Access Journals (Sweden)

    Sandra Maria Canelas Beer

    2003-12-01

    Full Text Available OBJETIVO: Determinar a prevalência de erros refrativos, estrabismo, ambliopia e anisometropia nas crianças pertencentes à população em estudo, utilizando dois métodos de rastreamento (triagem na escola e triagem durante o dia da vacinação contra a poliomielite. MÉTODOS: Foram examinadas 2.640 crianças, residentes da cidade de São Caetano do Sul, entre zero e seis anos de idade, divididas em duas amostras (A e B. A amostra A consistiu de 476 crianças que foram examinadas por dez oftalmologistas e onze técnicos oftálmicos, durante o Dia Nacional de Vacinação (20 de junho de 1998 contra a Poliomielite. A amostra B consistiu de 2.164 crianças que freqüentavam escolas municipais, entre quatro e seis anos de idade e foram examinadas por dois oftalmologistas durante o ano de 1998. RESULTADOS: Na amostra A, a prevalência de estrabismo foi de 3,36% e de anisometropia foi de 1,26%. O principal tipo de erro refrativo encontrado foi a hipermetropia PURPOSE: To establish the prevalence of refractive errors, strabismus, amblyopia and anisometropia, among children in a population, using two methods of screening (at school and at the National Polio Vaccination Day. METHODS: We examined 2,640 children, between 0 and 6 years of age. The children, residents of the city São Caetano do Sul, were divided into two groups (A and B. Group A: 476 children, with an age range of a few months to 6 years, had their eyes examined by 10 ophthalmologists and 11 ophthalmology technicians, during the National Polio Vaccination Day (June 20,1998. Group B: 2,164 children attending municipal schools (EMEIs and EMIs, between 4 and 6 years of age, who had their eyes examined by two ophthalmologists during the year of 1998. RESULTS: In group A, the prevalence of strabismus was 3.36% and that of anisometropia was 1.26%. The most common type of refractive error was hypermetropia £ 2D and 14.11% required optical prescription. In group B, the prevalence of strabismus

  7. Long-term efficacy of excimer laser in situ keratomileusis in the management of children with high anisometropic amblyopia

    Institute of Scientific and Technical Information of China (English)

    LIN Xiao-ming; YAN Xiao-he; WANG Zheng; YANG Bin; CHEN Qi-wen; SU Jin-ai; YE Xue-lian

    2009-01-01

    Background Children with anisometropic amblyopia are often noncompliant with traditional treatment including spectacules and contact lenses.This study was to evaluate the long-term efficacy of excimer laser in situ keratomileusis (LASIK) for children with high anisometropic amblyopia.Methods A retrospective analysis of 24 children with high unilateral anisometropic amblyopia,who underwent LASIK during the period between August 2000 and September 2005 in our hospital,was conducted.The mean age of these children was (7.4±1.9) years (range 5-14 years) and the mean follow-up period was (33.3±14.2) months (range 18.5-74.2 months).After LASIK,visual acuity,refraction and far or near stereoacuity were analyzed.Near stereoacuity was measured by the random-dot butterfly stereogram and the pre-school random-dot stereogram,while far stereoacuity was measured by the synoptophore with Yan's random-dot stereogram.Results Mean preoperative uncorrected visual acuity was 0.06±0.05,while mean postoperative uncorrected visual acuity was elevated to 0.43±0.33.Mean preoperative best-corrected visual acuity was 0.26±0.22,while mean postoperative best-corrected visual acuity was elevated to 0.67±0.40.For patients with myopic anisometropia,preoperative mean spherical equivalent refraction was (-8.01±2.70) D while postoperative value significantly reduced to (-1.32±2.47) D.For patients with hyperopic anisometropia,preoperative mean spherical equivalent refraction was (+7.35±1.55) D while postoperative value significantly reduced to (+3.30±0.86) D.These results demonstrated that there was statistical difference in these parameters between preoperative and postoperative tests.At the last follow-up,20 patients had near stereoacuity,and the mean near stereoacuities measured by the random-dot butterfly stereogram and the preschool random-dot stereogram were (149.00±152.93)" and (201.05±235.94)",respectively.In contrast,11 patients had far stereoacuity,and the mean far stereoacuity

  8. Association of extensive myelinated nerve fibers and high degree myopia: Case report

    Directory of Open Access Journals (Sweden)

    Elvan Yalcın

    2013-01-01

    Full Text Available Unilateral extensive myelination of the peripapillary nerve fibers may be associated with anisometropic myopia, strabismus, and reduced vision. Myelination of optic nerve fibers terminate at lamina cribrosa. Yet in some patients, myelination progresses into the peripapillary retinal nerve fibers and may affect the visual acuity. In this report, we described 4 patients. All patients presented extensive peripapillary myelinated nerve fibers associated with myopic anisometropia. After routine ophthalmic and orthoptic examinations, all patients underwent treatment for amblyopia through correction with spectacles, contact lenses, and the occlusion of the good eye. Corrected visual acuity improved in 1 patient, but 3 patients had no increase in visual acuity despite treatment with full cycloplegic refraction and appropriate patching. Probably because of structural abnormalies of the macula, visual results are often disappointing with appropriate correction of the refractive error and occlusion.

  9. Keratophakia and keratomileusis--clinical results.

    Science.gov (United States)

    Swinger, C A; Barraquer, J I

    1981-08-01

    A random, retrospective study was performed on 158 patients. who underwent keratophakia and keratomileusis for the correction of refractive errors. The primary indication for surgery was high anisometropia. Data on corneal curvature modification, refraction, accuracy, stability, and complications are reported. Both keratophakia and hypermetropic keratomileusis are capable of fully correcting aphakic hyperopia. Myopic keratomileusis corrected up to 16 diopters of myopia in this series. Lamellar refractive keratoplasty appears to have no significant detrimental effect on visual acuity. The majority of myopic patients had an improved best-corrected visual acuity postoperatively. High or irregular astigmatism was not noted following this surgery. The stability of the postoperative curvature appeared to be good with both keratophakia and myopic keratomileusis. Complications in this series were minimal, and one resulted in decreased vision postoperatively. Inaccuracy in achieving the desired refractive result appeared to be the major disadvantage of these techniques.

  10. Immediate Sequential Bilateral Cataract Surgery

    DEFF Research Database (Denmark)

    Kessel, Line; Andresen, Jens; Erngaard, Ditte

    2015-01-01

    The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS) with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence......-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were...... performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation). We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery...

  11. Current management of presbyopia

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    Pandelis A Papadopoulos

    2014-01-01

    Full Text Available Presbyopia is a physiologic inevitability that causes gradual loss of accommodation during the fifth decade of life. The correction of presbyopia and the restoration of accommodation are considered the final frontier of refractive surgery. Different approaches on the cornea, the crystalline lens and the sclera are being pursued to achieve surgical correction of this disability. There are however, a number of limitations and considerations that have prevented widespread acceptance of surgical correction for presbyopia. The quality of vision, optical and visual distortions, regression of effect, complications such as corneal ectasia and haze, anisometropia after monovision correction, impaired distance vision and the invasive nature of the currently techniques have limited the utilization of presbyopia surgery. The purpose of this paper is to provide an update of current procedures available for presbyopia correction and their limitations.

  12. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening.

    Science.gov (United States)

    Song, Shuang; Levi, Dennis M; Pelli, Denis G

    2014-05-05

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions-anisometropic amblyopia and apperceptive agnosia-each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need to

  13. O uso do "photoscreening" no estudo de fatores ambliopigênicos na população infantil The use of Photoscreening in the study of the amblyopigenics factors in children

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    Pedro Paulo Leite dos Reis

    2000-02-01

    Full Text Available Objetivo: Estudar a precisão do aparelho "MTI Photoscreener" na triagem de uma população infantil, identificando fatores ambliopigênicos como ametropias, anisometropias, estrabismos e cataratas congênitas e opacidades dos meios transparentes. Métodos: Durante o projeto "Veja Bem Brasil" os autores examinaram com uma máquina de "photoscreening" (MTI Photoscreener, 107 crianças, com idade variando entre 6 e 15 anos, comparando estes resultados com aqueles encontrados em posterior exame oftalmológico completo. Resultados: Ao final encontraram 31 (28,97% crianças com alguma patologia oftalmológica e 76 (71,02% dentro da normalidade. As análises estatísticas da precisão do aparelho revelaram os seguintes valores: sensibilidade 90,32%; especificidade, 96,05%; valores preditivos positivos e negativos de 90,32% e 96,05%, respectivamente. Conclusão: Os resultados acima citados demonstraram a confiabilidade do teste de "Photoscreening" na triagem de pacientes em idade escolar.Purpose: To study the accuracy of the MTI Photoscreener in the screening of an infantile population, for amblyopia causing factors such as ametropias, anisometropias, strabismus, congenital cataracts and opacities of the media. Methods: During the execution of a study project "Veja Bem Brasil" ("See Well Brazil", the AA used the MTI Photoscreener to examine 107 children, with ages varying from 6 to 15 years, and compared these results with those of a following complete ophthalmic examination. Results: The end results gave us 31 (28.97% children with an ophthalmic pathology and 76 (71.02% within normal limits. Statistical analysis showed the following values: sensivitity, 90.32%; specificity, 96.05%; positive predictive values and negative predictive values of 90.32% e 96.05%, respectively. Conclusion: The above results showed the "photoscreening" test to be reliable to screen young patients of school age.

  14. Screening Preschool Children for Visual Disorders: A Pilot Study

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    Suman Adhikari, BOptom

    2013-12-01

    Full Text Available Purpose: Ocular and/or vision defects are one of the most common reasons for the referral of young children to the hospital. Vision disorders are the fourth most common disability of children and the leading cause of handicapping conditions in childhood. In preschool-age children, amblyopia and amblyogenic risk factors, such as strabismus and significant refractive errors, are the most prevalent and important visual disorders. The purpose of this pilot study was to determine the prevalence of visual disorders in preschool children in Kathmandu Valley, Nepal.Methods: Four hundred and eighty-four children attending eight preschools in Kathmandu Valley underwent detailed optometric examination. Visual acuity was assessed with either Sheridan Gardiner or Kay Picture chart monocularly. Binocularity was assessed with cover test and prism bar neutralisation. Refraction was carried out in all children. In most instances this was done without the use of a cycloplegic agent. Stereopsis was assessed with the Lang stereo test. Anterior and posterior segment abnormalities were assessed by using a pen light, hand-held slit lamp, and direct ophthalmoscope.Results: Refractive error was the most common visual disorder. Considering our criteria of refractive error for myopia ≥ 0.50 D, hyperopia ≥ 1.50 D, astigmatism ≥ 1.00 D, and anisometropia ≥ 1.00 D, the overall prevalence of refractive error in our study was 31.82%. The overall prevalence of myopia, hyperopia, and astigmatism was 24.17%, 2.48%, and 5.17%, respectively. Anisometropia was present in 1.65% of the participants, and 2%, 1.4%, and 0.2% had strabismus, amblyopia, and nystagmus, respectively.Conclusion: The relatively high prevalence of refractive error in our studied population needs more attention. The results suggest that there is a need for a large-scale community-based preschool screening program in Nepal so that affected children can be identified early and appropriate treatment can be

  15. Prevalence of refractive errors among primary school children in a tropical area,Southeastern Iran

    Institute of Scientific and Technical Information of China (English)

    Monireh Mahjoob; Samira Heydarian; Jalil Nejati; Alireza Ansari-Moghaddam; Nahid Ravandeh

    2016-01-01

    Objective: To determine the prevalence of refractive errors among primary school children in Zahedan District, Southeastern Iran, as a tropical area.Methods: In this cross sectional study, a total of 400 students were selected randomly using multi-stage sampling technique. Myopia was defined as spherical equivalent(SE)of-0.5 diopter(D) or more, hyperopia was defined as SE of +2.00 D or more and a cylinder refraction greater than 0.75 D was considered astigmatism. Anisometropia was defined as a difference of 1 D or more between two eyes. Cycloplegic refractive status was measured using auto-refractometer(Topcon 8800). Data were analyzed using SPSS,version 22 software program.Results: Mean ± SD of SE was(1.71 ± 1.16) D. A total of 20 students [6.3%, 95%confidence interval(CI): 3.96%–9.64%] were myopic(-0.5 D), 186 students(58.1%,95% CI: 52.50%–63.56%) were hyperopic( +2.00 D) and 114 students(35.6%, 95%CI: 30.43%–41.18%) were emmetropic. The prevalence of astigmatism( 0.75 D)among students was 3.4%(95% CI: 1.82%–6.25%). Anisometropia of 1 D or more was found in 21.3%(95% CI: 16.98%–26.23%) of the studied population. The prevalence of refractive errors was higher among girls than boys(73.1% vs. 55.6%, P = 0.001), but it was not significantly different among different age groups(P = 0.790).Conclusions: Refractive errors affect a sizable portion of students in Zahedan. Although myopia is not very prevalent, the high rate of hyperopia in the studied population emphasizes its need for attention.

  16. [Features of the electronic eikonometer for the study of binocular function].

    Science.gov (United States)

    Bourdy, C

    2013-05-01

    After presenting the components of this electronic eikonometer (device schematic and organizational chart) for the analysis and measurement of perceptive effects of binocular disparity, we review the specifics (tests with incorporated magnifications seen in polarized light) and the advantages of this device as compared to existing eikonometers (absence of any intermediary optical system). We provide a list of available tests in the test library and their parametric characteristics: Ogle Spatial Test for Aniseikonia, Fixation Disparity Test: binocular nonius, and Linear and Random stereoscopic tests. We develop a methodology adapted to each type of test and the manipulations to be performed by the operators and observers. We then provide some results of examinations performed with this eikonometer for a sample of observers equipped with glasses, contact lenses or implants. We propose an analysis of these various perceptive effects from experimental and theoretical studies: association between Depth, Disparity and Fusion; brief review of theoretical studies by automatic matrix calculus of retinal image size for various types of eyes: emmetropic and isometropic eyes based on various dioptric elements from Gullstrand's eye, axial anisometropia, anisometropia of conformation, aphakia resulting from these various eyes. We demonstrate the role of these studies in the analysis of subjective measurements of aniseikonia and for the choice of best correction: variations in amplitude and sign of the monocular components of the fixation disparity as a function of the viewing distance, Complexity of depth perception, according to the test used. Considering the evolution of the technology used for the realization of this prototype, we propose that this eikonometer be updated, in particular by using high-resolution flat screens, which would allow improvement and enrichment of the test library (definition, contrast and size of the observed images).

  17. Refractive status at birth: its relation to newborn physical parameters at birth and gestational age.

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    Raji Mathew Varghese

    Full Text Available BACKGROUND: Refractive status at birth is related to gestational age. Preterm babies have myopia which decreases as gestational age increases and term babies are known to be hypermetropic. This study looked at the correlation of refractive status with birth weight in term and preterm babies, and with physical indicators of intra-uterine growth such as the head circumference and length of the baby at birth. METHODS: All babies delivered at St. Stephens Hospital and admitted in the nursery were eligible for the study. Refraction was performed within the first week of life. 0.8% tropicamide with 0.5% phenylephrine was used to achieve cycloplegia and paralysis of accommodation. 599 newborn babies participated in the study. Data pertaining to the right eye is utilized for all the analyses except that for anisometropia where the two eyes were compared. Growth parameters were measured soon after birth. Simple linear regression analysis was performed to see the association of refractive status, (mean spherical equivalent (MSE, astigmatism and anisometropia with each of the study variables, namely gestation, length, weight and head circumference. Subsequently, multiple linear regression was carried out to identify the independent predictors for each of the outcome parameters. RESULTS: Simple linear regression showed a significant relation between all 4 study variables and refractive error but in multiple regression only gestational age and weight were related to refractive error. The partial correlation of weight with MSE adjusted for gestation was 0.28 and that of gestation with MSE adjusted for weight was 0.10. Birth weight had a higher correlation to MSE than gestational age. CONCLUSION: This is the first study to look at refractive error against all these growth parameters, in preterm and term babies at birth. It would appear from this study that birth weight rather than gestation should be used as criteria for screening for refractive error

  18. Exposure to sunlight reduces the risk of myopia in rhesus monkeys.

    Science.gov (United States)

    Wang, Yong; Ding, Hui; Stell, William K; Liu, Liangping; Li, Saiqun; Liu, Hongshan; Zhong, Xingwu

    2015-01-01

    Exposure to sunlight has recently been postulated as responsible for the effect that more time spent outdoors protects children from myopia, while early life exposure to natural light was reported to be possibly related to onset of myopia during childhood. In this study, we had two aims: to determine whether increasing natural light exposure has a protective effect on hyperopic defocus-induced myopia, and to observe whether early postnatal exposure to natural light causes increased risk of refractive error in adolescence. Eight rhesus monkeys (aged 20-30 days) were treated monocularly with hyperopic-defocus (-3.0D lens) and divided randomly into two groups: AL group (n=4), reared under Artificial (indoor) Lighting (08:00-20:00); and NL group (n=4), exposed to Natural (outdoor) Light for 3 hours per day (11:00-14:00), and to indoor lighting for the rest of the light phase. After being reared with lenses for ca. 190 days, all monkeys were returned to unrestricted vision until the age of 3 years. Another eight age-matched monkeys, reared with unrestricted vision under artificial lighting since birth, were employed as controls. The ocular refraction, corneal curvature and axial dimensions were measured before lens-wearing (at 23±3 days of age), monthly during the light phase, and at the age of puberty (at 1185+3 days of age). During the lens-wearing treatment, infant monkeys in the NL group were more hyperopic than those in the AL group (F=5.726, P=0.032). Furthermore, the two eyes of most NL monkeys remained isometropic, whereas 3 of 4 AL monkeys developed myopic anisometropia more than -2.0D. At adolescence, eyes of AL monkeys showed significant myopic anisometropia compared with eyes of NL monkeys (AL vs NL: -1.66±0.87D vs -0.22±0.44D; P=0.002) and controls (AL vs Control: -1.66±0.87D vs -0.05±0.85D; Pmonkey.

  19. Reabilitação visual com lentes de contato após trauma ocular Visual rehabilitation with contact lenses after ocular trauma

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    Adamo Lui Netto

    2008-12-01

    Full Text Available Trauma ocular é causa importante de baixa de acuidade visual em todos os países do mundo. A integridade do bulbo ocular é primordial para recuperação visual nesses pacientes. Acidentes domésticos, automobilísticos, esportivos, além de queimaduras químicas e térmicas são as principais causas de trauma em nosso meio. O uso de lentes de contato é indicado para a reabilitação visual em casos de astigmatismos regulares ou irregulares de córnea, anisometropias, afacias, opacidades paracentrais superficiais ou profundas na córnea decorrentes do trauma ocular. As lentes de contato podem ser utilizadas no pós-trauma com finalidade terapêutica ou para correção visual. As lentes mais utilizadas para correção visual pós-trauma são as lentes de contato rígidas gás permeáveis, com alto coeficiente de permeabilidade. As lentes de contato gelatinosas podem ser usadas imediatamente após o trauma ocular com finalidade terapêutica e mais tardiamente para correção óptica em afacias e anisometropias traumáticas. A lente de contato é parte importante no tratamento tardio do trauma ocular, propiciando melhora significativa da acuidade visual na maioria dos casos.Ocular trauma is an important cause of visual acuity loss worldwide. Visual recovery is related to anatomical integrity. The main causes of trauma are domestic and automobilist accidents, sports practice and chemical or thermic burns. Contact lens is indicated for visual rehabilitation in cases of corneal regular and irregular astigmatisms, anisometropic and aphakic patients and in cases of deep or superficial corneal opacities that do not affect the visual axis. Contact lens can be used in the post- trauma period for therapeutic and optical purposes. Rigid gas permeable contact lens, with a high permeability index, is the most used for optical purpose. Soft contact lens can be used immediately after trauma as therapy or later for optical correction in aphakic and

  20. Measuring aniseikonia using scattering filters to simulate cataract

    Science.gov (United States)

    Wilson, Jason

    2011-12-01

    The relationship between anisometropia and aniseikonia (ANK) is not well understood. Ametropic cataract patients provide a unique opportunity to study this relationship after undergoing emmetropizing lens extraction. Because light scatter may affect ANK measurement in cataract patients, its effect should also be evaluated. The Basic Aniseikonia Test (BAT) was evaluated using afocal size lenses to produce specific changes in retinal height. Several light scattering devices were then evaluated to determine which produced effects most similar to cataract. Contrast sensitivity and visual acuity (VA) losses were measured with each device and compared to those reported in cataract. After determining the most appropriate light scattering device, twenty healthy patients with normal visual function were recruited to perform the BAT using the filters to simulate cataract. Cataract patients were recruited from Vision America and the University of Alabama at Birmingham School of Optometry. Patients between 20 and 75 years of age with at least 20/80 VA in each eye, ≥ 2D ametropia, and normal binocular function were recruited. Stereopsis and ANK were tested and each patient completed a symptom questionnaire. ANK measurements using afocal size lenses indicated that the BAT underestimates ANK, although the effect was minimal for vertical targets and darkened surroundings, as previously reported. Based on VA and contrast sensitivity loss, Vistech scattering filters produced changes most similar to cataract. Results of the BAT using Vistech filters demonstrated that a moderate cataract but not a mild cataract may affect the ANK measurement. ANK measurements on cataract patients indicated that those with ≥ 2 D ametropia in each eye may suffer from induced ANK after the first cataract extraction. With upcoming healthcare reform, unilateral cataract extraction may be covered, but not necessarily bilateral, depending on patient VA in each eye. However, a questionnaire about symptoms

  1. The Estimation of Higher Order Aberrations in Children with Anisometropic Amblyopic%高阶像差在远视儿童屈光参差性弱视中的评价

    Institute of Scientific and Technical Information of China (English)

    邱煦; 谭琦; 廖孟; 刘陇黔

    2011-01-01

    使用美国ZYWAVEⅡ像差分析仪对54例屈光参差性远视弱视儿童共108只眼进行像差检查,就像差均方根(RMS)分布情况进行统计分析研究,观察各类高阶像差(HOAs)分布、屈光参差性弱视程度与HOAs的关系.所有患儿弱视眼的总HOAs、总彗差(TC)、总球差(TSA)、总5阶像差(RMS5)的均方根逐阶递减.弱视眼各阶像差均方根值均大于对测眼,但无统计学差异.弱视眼随弱视程度增大,TC、TSA和RMA5呈递增趋势.弱视眼TSA与屈光参差度正相关.HOAs可能在屈光参差性弱视的发展中起了一定作用,但不是主要影响因素.%Higher order aberrations (HOAs) were measured in 54 anisometropic amblyopic children using the ZY-WAVE II aberrometer. The results were compared in normal fellow and amblyoic eyes which were determined by the corrected visual acuity. Between the normal eyes and anisometropic amblyopic eyes, no statistically significant difference were found in mean root square of total HOAs, total coma (TO ? Total spherical aberration (TSA), and the 5th root mean square (RMS5). There was no correlation among best corrected visual acuity (BCVA)t HOAst TC. TSA, and RMS5, There was some positively correlation between the degree of anisometropia and TC. HOAs increase with the increasing of the degree of anisometropic amblyopia. Lower order aberrations are the main refractive factors leading to amblyopia. And HOAs is related to anisometropia amblyopia. The study helps us understand the mechanism of amblyopia and make the further study.

  2. Visual Motor and Perceptual Task Performance in Astigmatic Students

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    Erin M. Harvey

    2017-01-01

    Full Text Available Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D or bilateral astigmatism group (right and left eye ≥ 1.00 D based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI and Visual Perception (VMIp. Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88. Mean VMI score in corrected astigmats did not differ from the control group (p=0.829. Uncorrected astigmats had lower VMI scores than the control group (p=0.038 and corrected astigmats (p=0.007. Mean VMIp scores for uncorrected (p=0.209 and corrected astigmats (p=0.124 did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p=0.003. Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

  3. Axial Length and Corneal Curvature in Anisometropic Amblyopia in Nepalese Children

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    Safal Khanal, B Optom

    2014-05-01

    Full Text Available Background: Purpose/Aim: To assess ocular parameters in Nepalese children with severe anisometropic amblyopia. Methods: This was a hospital-based cross-sectional analytical study conducted in a tertiary eye center in Nepal. Twentyone children aged 7-12 years with severe anisometropic amblyopia (>3D of anisometropia were included in the study. Relevant demographic and clinical data were obtained. Axial length, corneal curvature, and anterior chamber depth were measured in both the amblyopic and fellow eye, along with detailed anterior and posterior segment evaluation. Results: In anisomyopia, amblyopic eyes had longer axial length than the fellow eyes (p<.05, while in the cases with anisohyperopia, amblyopic eyes had shorter axial lengths than the fellow eyes (p<.05. The difference in corneal astigmatism between the amblyopic and fellow eye in children with anisoastigmatism was clinically and statistically significant (p<.05. However, there was no significant difference between the axial lengths in the amblyopic and the fellow eyes (p=.84. Conclusion: Difference in axial length was responsible for the difference in spherical refractive error in children with anisometropic amblyopia with no significant difference in corneal astigmatism, whereas corneal curvature was the significant factor responsible for amblyopia resulting from anisoastigmatism.

  4. [Treating anisometric amblyopia with HTS Amblyopia iNet Software--preliminary results].

    Science.gov (United States)

    Avram, Elena; Stănilă, Adriana

    2013-01-01

    Amblyopia or "lazy eye" represents a disorder of the visual system characterized by poor vision in an eye that is otherwise physically normal. Anisometropia, the condition in which the two eyes have an unequal refractive error, is considered the second most common cause of amblyopia. The purpose of this study is to determine the efficiency of HTS Amblyopia iNet Software by studying the progress of visual acuity, contrast sensitivity and stereopsis vision in anisometropic amblyopic children. 5 patients (age: 5-13 years), treated with HTS Amblyopia iNet Software at OftaTotal Clinic from Sibiu, between 2010-2013, participated in this clinical trial. Initially, visual acuity ranged from 0.25 to 0.8, contrast sensitivity from 1.35 to 1.65 Log. Unit. and 1 patient presented stereoscopic vision. After treatment, visual acuity ranged from 0.8 to 1, contrast sensitivity from 1.35 to 1.95 Log. Unit., also all patients presented stereoscopic vision. HTS Amblyopia iNet Software represents an effective modern approach in the treatment of anisometropic amblyopia.

  5. Prevenção à cegueira em crianças de 3 a 6 anos assistidas pelo programa de saúde da família (PSF do Morro do Alemão - Rio de Janeiro Blindness prevention on 3 to 6 years old children at a health family program assisted community in Morro do Alemão - Rio de Janeiro

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    Giancarlo Cardoso Jeveaux

    2008-10-01

    Full Text Available OBJETIVO: Este trabalho visou fazer um levantamento da prevalência de ambliopia e fatores ambliopiogênicos em crianças com idade pré-escolar em áreas assistidas pelo Programa de Saúde da Família no Morro do Alemão-RJ. MÉTODOS: Crianças com idade entre 3 e 6 anos foram submetidas a exame de triagem visual. Os resultados positivos foram confirmados por exame oftalmológico realizado sob cicloplegia na própria unidade de saúde. Foram aplicados questionários semi-estruturados aos acompanhantes das crianças e aos membros de todas as equipes de saúde da unidade. RESULTADOS: De 559 crianças convocadas para triagem, 265 (47,4% compareceram e, destas, 127 (48% foram encaminhadas para exame oftalmológico completo. Tiveram o exame ocular normal 138 (52% das crianças examinadas pela triagem. Compareceram para exame especializado 81 (63,7% crianças. Destas, 9 (4,1% crianças tiveram diagnóstico de ambliopia. Quatro (1,8% por estrabismo, uma (0,46% por privação de estímulo, uma (0,46% por anisometropia e três (33,3% por erros refracionais isometrópicos. CONCLUSÃO: Os dados obtidos pela triagem seguida de exame ocular especializado executada na unidade de atenção primária à saúde (PSF do Morro do Alemão-RJ, mostraram que os exames de triagem realizados são relevantes para a detecção de ambliopia e fatores ambliopiogênicos e para a promoção da saúde ocular infantil.PURPOSE: The study objective is to determine the prevalence of amblyopia and amblyopiogenic factors in children from 3 to 6 years old at a health family program assisted community in Morro do Alemão-RJ. METHODS: A preschool children ocular evaluation cross sectional study will be submitted to an ophthalmic screening exam.The positive results were confirmed by oftalmologic examination under cicloplegia inside of the health centre. Were applied a semi-structure questionnaire to the health members of the health centre team and to all children accompanist. RESULTS

  6. Practitioners’ opinions on the presentation of ocular pathology and ametropia in patients wearing ready-made reading spectacles

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    K. C. Phillips

    2008-01-01

    Full Text Available This paper presents the findings of a study to determine optometrists’ opinions on the presentation of ocular pathology and ametropia in patients wearing ready-made reading spectacles. Ninety-seven optometrists completed a questionnaire pertaining to ametropia and ocular diseases among these patients. The questionnaire contained information regarding patient demographics, ocular pathology, ocular ametropia and the regulatory and public health aspects of ready-made readers.Ninety-five percent of respondents stated that they had seen patients with ready-made readers in their practice and 62% of these stated that they had found the presence of ocular pathology in these patients. The pathologies most commonly reported as seen by practitioners were dry eye (86% of practitioners, cataracts (80% and diabetic retinopathy (54%. In addition, 39% of practitioners reported seeing patients with anisometropia. The majority of practitioners (71% stated that they sold ready-made readers in their practice. Sixty-three percentof practitioners indicated that they would be prepared to offer a service whereby a reduced consultation fee and a pair of ready-made readers could be incorporated into an indigent “package”. An overwhelming 88% of the practitioners felt that the sale of ready-made readers should be more regulated and 74% of practitioners felt that the Professional Board for Optometry and Dispensing Opticians should be responsible for monitoring their sale. The research suggests that wearers of ready-made readers should be screened for ocular pathology, reduced visual acuity and amblyopia. Current regulations should be tightened and a public awareness education campaign should be initiated. The use of ready-made reading spectacles, in deference to an eye examination by an optometrist, appears to be largely as a result of the perceived costs of pri-vate practice combined with ignorance and apathy

  7. Neuromuscular plasticity and rehabilitation of the ocular near response.

    Science.gov (United States)

    Schor, Clifton M

    2009-07-01

    The near response is composed of cross-coupled interactions between convergence and other distance-related oculomotor responses including accommodation, vertical vergence, and cyclovergence. The cross-coupling interactions are analogous to the body postural reflexes that maintain balance. Near-response couplings guide involuntary motor responses during voluntary shifts of distance and direction of gaze without feedback from defocus or retinal-image disparity. They optimize the disparity stimulus for stereoscopic depth perception and can be modified by optically induced sensory demands placed on binocular vision. In natural viewing conditions, the near response is determined by passive orbital mechanics and active-adaptable tonic components. For example, the normal coupling of vertical vergence with convergence in tertiary gaze is partly a byproduct of passive orbital mechanics. Both, adapted changes of vertical vergence in response to anisophoria, produced by unequal ocular magnification (aniseikonia), and adapted changes in the orientation of Listing's plane in response to torsional disparities can be achieved by a combination of passive orbital mechanics and neural adjustments for the control of the vertical vergence and cyclovergence. Adaptive adjustments are coupled with gaze direction, convergence angle, and head tilt. Several adaptation studies suggest that it is possible to achieve non-linear changes in the coupling of both vertical vergence and cyclovergence with gaze direction. This coupling can be achieved with changes in neural control signals of ocular elevator muscles that are cross-coupled with both convergence and direction of tertiary gaze. These linear and non-linear coupling interactions can be adapted to compensate for (1) anisophoria induced by spectacle corrections for anisometropia, (2) accommodative esotropia, (3) convergence excess and insufficiency, and (4) non-concomitant deviations with ocular torticollis associated with trochlear palsy

  8. Intraocular lens exchange for high myopia in pseudophakic children.

    Science.gov (United States)

    Kraus, C L; Trivedi, R H; Wilson, M E

    2016-09-01

    PurposeThe purpose of this study was to examine the preoperative factors and postoperative outcomes following intraocular lens (IOL) exchange for high myopia in pseudophakic children.MethodsThe medical records of all patients undergoing IOL exchange for high myopia were retrospectively reviewed.ResultsA total of 15 eyes were identified that had undergone an IOL exchange for myopic shift. Average age of cataract extraction (CE) was 5.4 months. In all, 10/15 had a unilateral cataract. IOL exchange usually occurred at an average of 6 years following cataract surgery. The average spherical equivalent (SE) of the refractive error at that time was -9.6 D. Following IOL exchange, SE was -1.3 D. A two-line reduction in best-corrected visual acuity was observed in 1/13 of our patients for whom pre- and post-exchange data were available. The average axial length (AL) of the eye undergoing the IOL exchange was 24.0 mm, average AL in the non-operative eye was 22.1 mm. On average, the operative eyes grew 4.4 mm and the non-operative eyes 3.02 mm. No adverse events were seen in the operative eyes.ConclusionYounger age at the time of CE creates a greater likelihood of AL elongation and predisposes a child to myopic shift. IOL exchange should be considered an option to reduce anisometropia and associated aniseikonia to improve visual outcomes. Successful visual rehabilitation and predictable post-exchange refractions were seen with our patients.

  9. Is Noncycloplegic Photorefraction Applicable for Screening Refractive Amblyopia Risk Factors?

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    Zhale Rajavi

    2012-01-01

    Full Text Available Purpose: To compare the accuracy of noncycloplegic photorefraction (NCP with that of cycloplegic refraction (CR for detecting refractive amblyopia risk factors (RARFs and to determine cutoff points. Methods: In this diagnostic test study, right eyes of 185 children (aged 1 to 14 years first underwent NCP using the PlusoptiX SO4 photoscreener followed by CR. Based on CR results, hyperopia (≥ +3.5 D, myopia (≥ -3 D, astigmatism (≥ 1.5 D, and anisometropia (≥ 1.5 D were set as diagnostic criteria based on AAPOS guidelines. The difference in the detection of RARFs by the two methods was the main outcome measure. Results: RARFs were present in 57 (30.8% and 52 (28.1% of cases by CR and NCP, respectively, with an 89.7% agreement. In contrast to myopia and astigmatism, mean spherical power in hyperopic eyes was significantly different based on the two methods (P < 0.001, being higher with CR (+5.96 ± 2.13 D as compared to NCP (+2.37 ± 1.36 D. Considering CR as the gold standard, specificities for NCP exceeded 93% and sensitivities were also acceptable (≥ 83% for myopia and astigmatism. Nevertheless, sensitivity of NCP for detecting hyperopia was only 45.4%. Using a cutoff point of +1.87 D, instead of +3.5 D, for hyperopia, sensitivity of NCP was increased to 81.8% with specificity of 84%. Conclusion: NCP is a relatively accurate method for detecting RARFs in myopia and astigmatism. Using an alternative cutoff point in this study, NCP may be considered an acceptable device for detecting hyperopia as well.

  10. Asynchrony Detection in Amblyopes

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    Pi-Chun Huang

    2012-10-01

    Full Text Available Amblyopia is a developmental abnormality of visual cortex. Although amblyopes experience perceptual deficits in spatial vision tasks, they have less temporal sensitivity loss. We investigated whether their temporal synchrony sensitivity is impaired. In experiment 1, four Gaussian blobs, located at the top, bottom, left, and right of a presentation screen, were flickering in 3 Hz and one of them was flickering in out-of-phase fashion in time. Participants needed to tell which blob was different from the other three and contrast threshold of the blobs was measured to determine the synchrony detection threshold. We found the thresholds were not correlated with the contrast thresholds for detecting the flickering blobs, suggesting synchrony detection and temporal detection threshold are processed by different mechanisms. In experiment 2, synchrony thresholds were measured as participants' ability to tell if one of the four high contrast Gaussian blobs was flickering asynchronously in time. Three temporal frequencies (1, 2, and 3 Hz and two element separations (1.25 and 5 deg were compared. We found that the amblyopic group exhibited a deficit only for the 1.25 deg element separation in amblyopic eye but was normal for the other configurations compared to controlled participants. It suggests amblyopes have deficits in temporal processing but only for foveal vision. We also found the sensitivity for the non-strabismic anismetropia group is reduced for all three temporal frequencies whereas for the strabismic anisometropia group it was reduced at 3Hz only, suggesting the impairment in temporal synchrony might be different for different types of amblyopia.

  11. Prevalence of refractive errors in Villa Maria, Córdoba, Argentina

    Institute of Scientific and Technical Information of China (English)

    Victoria M Snchez; Claudio P Juarez; Rafael Iribarren; Santiago G Latino; Victor E Torres; Ana L Gramajo; Mara N Artal; Mara B Yadarola; Patricia R Garay; Jos D Luna

    2016-01-01

    Background: Refractive errors are among the most frequent reasons for demand of eye-care services. Publications on refractive errors prevalence in our country are few. This study has the purpose to assess the prevalence of refractive errors in an adult population of Villa Maria, Córdoba, Argentina. Methods: The Villa Maria Eye Study is a population-based cross-sectional study conducted in the city of Villa Maria, Córdoba, Argentina from May 2008 to November 2009. Subject’s aged 40+ received a demographic interview and complete ophthalmological exam. Visual acuity was obtained with an ETDRS chart. Cycloplegic auto refraction was performed. The spherical equivalent was highly correlated between right and left eyes, so only data of right eyes are presented. Myopia and hyperopia were defined with a ±0.50 diopters (D) criterion and astigmatism >1 D. Results: This study included 646 subjects, aged 40 to 90 (mean age: 59.6±10.3 years old). Four hundred and sixty two (71.5%) were females. The mean spherical equivalent was +0.714±2.41 D (range, −22.00 to+8.25 D) and the power of the cylinder was, on average, −0.869±0.91 D (range, 0 to −6.50 D). In this sample, 61.6% subjects were hyperopic, and 13.5% were myopic. Myopia prevalence was lower in men (9.8% versus 14.9%) but this difference among genders was not statistically signiifcant. There were 141 subjects (21.8%) with anisometropia greater than 1 D, and 168 subjects (26.0%) with astigmatism greater than 1 D. Conclusions: The present study shows the prevalence of cycloplegic refractive errors in an adult population of Argentina. The prevalence of hyperopia was high, while myopia prevalence was very low.

  12. 硬性透氧性角膜接触镜矫正特殊类型屈光不正的效果观察%The rigid gas permeable contact lens for the correction of special ametropia

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    常枫; 沈政伟; 陈云辉; 魏润菁; 周和政

    2011-01-01

    Objective To evaluate the effectiveness and safety of rigid gas permeable contact lenses (RGPCL) for special ametropia. Methods Of 61 patients (98 eyes), including high myopia 29 (55 eyes), high degree of astigmatism 9 (18 eyes), 20 non-lens high hyperopia (20 eyes), anisometropia 3 (5 eyes), were fitted with RGPCLs. They were followed up for 6 to 12 months. Results High myopia to wear spectacles and RGPCLs, Best corrected visual acuity (BCVA) ≥ 4.9 were 37 eyes (67.27%) and 47 (85.46%) respectively, the average BCVA RGPCLs better than spectacles (P 0.05). In the high astigmatism group, BCVA was better than 4.9 in 20 eyes (100%) with RGPCLs and in 15 eyes (75%) with spectacles. The average BCVA, RGPCLs were better than spectacles (P 0.05);高度散光组佩戴框架眼镜和RGPCL后矫正视力≥4.9分别为15只眼(75%)、20只眼(100%),平均最佳矫正视力RGPCL好于框架眼镜(P<0.05);屈光参差者佩戴RGP后达到双眼平衡.随访未发现明显眼部并发症.结论 对于特殊类型屈光不正,RGPCL的视觉效果明显优于框架眼镜,并有较高地安全性,无明显并发症发生.

  13. Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations

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    Ai-Hong Chen

    2012-01-01

    Full Text Available Background: Visual acuity is an essential estimate to assess ability of the visual system and is used as an indicator of ocular health status. Aim: The aim of this study is to investigate the consistency of acuity estimates from three different clinical visual acuity charts under two levels of ambient room illumination. Materials and Methods: This study involved thirty Malay university students aged between 19 and 23 years old (7 males, 23 females, with their spherical refractive error ranging between plano and −7.75D, astigmatism ranging from plano to −1.75D, anisometropia less than 1.00D and with no history of ocular injury or pathology. Right eye visual acuity (recorded in logMAR unit was measured with Snellen letter chart (Snellen, wall mounted letter chart (WM and projected letter chart (PC under two ambient room illuminations, room light on and room light off. Results: Visual acuity estimates showed no statistically significant difference when measured with the room light on and with the room light off (F1,372 = 0.26, P = 0.61. Post-hoc analysis with Tukey showed that visual acuity estimates were significantly different between the Snellen and PC (P = 0.009 and between Snellen and WM (P = 0.002. Conclusions: Different levels of ambient room illumination had no significant effect on visual acuity estimates. However, the discrepancies in estimates of visual acuity noted in this study were purely due to the type of letter chart used.

  14. Aniseikonia and Foveal Microstructure after Retinal Detachment Surgery.

    Science.gov (United States)

    Okamoto, Fumiki; Sugiura, Yoshimi; Okamoto, Yoshifumi; Hiraoka, Takahiro; Oshika, Tetsuro

    2014-07-17

    Purpose:To quantify aniseikonia after successful surgical repair of rhegmatogenous retinal detachment (RD), and to investigate the relationship between the severity of postoperative aniseikonia and retinal microstructures as well as clinical parameters. Methods:The study included 106 eyes of 106 patients, without any history of ocular disease/surgery and less than 2 diopters of anisometropia, who had undergone successful retinal reattachment surgery. Aniseikonia was measured with New Aniseikonia Test and foveal microstructure was assessed with the spectral-domain optical coherence tomography at 6 months postoperatively. Results:Twenty-eight of 106 patients (26%) had micropsia, 17 patients (16%) had macropsia, and 61 patients (58%) had no aniseikonia. The mean absolute value of aniseikonia was 2.3 ± 2.9% (range; -12.5% - +12.0%). Of 57 eyes with macula-on RD, 3 had micropsia and 12 had macropsia. Of 49 eyes with macula-off RD, 25 had micropsia and 5 had macropsia. Eyes with micropsia mostly exhibited persistent or transient cystoid macular edema, subretinal fluid, hyperreflective or disruption of IS/OS line, while most of the eyes with macropsia presented epiretinal membrane. Stepwise multiple regression analysis revealed that postoperative best-corrected visual acuity and the area of RD were significantly relevant to the mean absolute value of aniseikonia. Conclusions:These results suggested that about half of patients with successful repair of RD had aniseikonia. Eyes with macula-off RD tended to show micropsia, while those with macula-on RD mostly presented macropsia. Micropsia and macropsia were primarily caused by respective specific abnormal structures at the foveal region.

  15. Factors Influencing the Surgical Success in Patients with Intermittent Exotropia

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    Uğur Acar

    2013-04-01

    Full Text Available Pur po se: To determine the factors that influence surgical success in patients with intermittent exotropia. Ma te ri al and Met hod: We retrospectively evaluated the records of patients with intermittent exotropia who were diagnosed, operated, and followed up. Successful outcome was defined as alignment ≤10 prism diopters (PD esophoria or exophoria at the last follow-up visit. The clinical findings, exodeviation types, surgical ages, operation types, preoperative and postoperative deviation amounts, presence of anisometropia and amblyopia, presence of A- or V-pattern, and presence of binocular vision and stereoacuity of patients were evaluated. We investigated the independent variables that affected the surgical success in intermittent exotropia patients. Re sults: Among the 379 patients included in the study, 266 (70.18% underwent surgery, and the success rate was 68.05% (181 patients. In this successful surgery group, mean deviation was 25.82±11.27 PD at near and 30.80±10.59 PD at distance versus 30.93±12.47 PD and 34.92±11.02 PD, respectively, in the unsuccessful surgery group. There was a statistically significant difference between the two groups. Preoperative factors, such as presence of binocular vision preoperatively, and postoperative factors, such as followup period and the patients' deviation amount in the 1st week and 6th month, were found to affect the surgical outcome. Dis cus si on: The success rate of surgical treatment of intermittent exotropia increases in the patients with presence of fusion and low preoperative deviation amounts. Also, in the early postoperative period, orthophoric or ≤10 PD esophoric patients have a higher final surgical success rate. (Turk J Ophthalmol 2013; 43: 107-12

  16. [Electronic eikonometer: Measurement tests displayed on stereoscopic screen].

    Science.gov (United States)

    Bourdy, C; James, Y

    2016-05-01

    We propose the presentation on a stereoscopic screen of the electronic eikonometer tests intended for analysis and measurement of perceptual effects of binocular disparity. These tests, so-called "built-in magnification tests" are constructed according to the same principle as those of preceding eikonometers (disparity variation parameters being included in each test presentation, which allows, for test observation and measurements during the examination, the removing of any intermediate optical system). The images of these tests are presented separately to each eye, according to active or passive stereoscopic screen technology: (1) Ogle Spatial Test to measure aniseikonia; (2) Fixation Disparity test: binocular nonius; (3) retinal correspondence test evaluated by nonius horopter; (4) stereoscopic test using Julesz' random-dot stereograms (RDS). All of these tests, with their variable parameters included, are preprogrammed by means of an associated mini-computer. This new system (a single screen for the presentation of tests for the right eye and left eye) will be much simpler to reproduce and install for all practitioners interested in the functional exploration of binocular vision. We develop the suitable methodology adapted to each type of examination, as well as manipulations to be performed by the operator. We then recall the possibilities for reducing aniseikonia thanks to some theoretical studies previously performed by matrix calculation of the size of the retinal images for different types of eye (emmetropia, axial or conformation anisometropia, aphakia) and for different means of correction (glasses, contact lenses, implants). Software for achieving these different tests is available, on request, at this address: eiconometre.electronique@gmail.com.

  17. Effect of ametropic and anisometropic amblyopia on the development of children's stereoscopic function%儿童屈光不正性与屈光参差性弱视对立体视功能发育的影响

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    崔爱芝; 刘桂香; 崔从先; 吴坤; 张爱华

    2013-01-01

    Objective To investigate and compare the differences between ametropic and anisometropic amblyopia stereoscopic function of children with.Methods Sixty-three ametropic or anisometropic amblyopia children whose corrected visual acuity was recovered to normal were included.According to the result of retinoscopy after mydriasis in the first visit,the patients were divided into two groups:Group A (ametropia group,41 cases) and Group B (Anisometropia group,22 cases).In addition,according to first visit age of the children,they were divided into 3 groups:Group a (≥3 years old,7 cases),Group b (3 ~ 6 years old) 47 cases,and Group c (≥6 years old) 9 cases.Synoptophore and Yan Shaoming Stereoscopic Vision Control Chart were used to examine their far and near stereoscopic respectively.The statistically differences between far and near stereopsis were analyzed among the groups.Results Nineteen children owed the normal far stereoscopic and 5 owed the normal near stereoscopic among the 63 cases.Sixteen children (39.0%) of Groups A and three children (14.3%) of Groups B owned the normal far stereoscopic,and differences between the two groups showed statistical significance (P <0.05).Four (9.7%) children got the normal near stereoscopic in Group A,and one (4.5%) in Group B.Differences between the two groups did not show any significant (P >0.05).In the three groups of a,b,and c,the far stereoscopic differences between a and b and between a and c showed statistical significance (P <0.01,P <0.05),but the far stereoscopic difference between b and c has no significant (P >0.05).The near stereoscopic differences among the three groups had no significant (P >0.05).After treatment,among the 63 cases of amblyopia children 19 (30.2%) got the normal far stereoscopic vision and only five (7.9%) got the near stereoscopic vision,there were statistically significant difference between far and near stereoscopic vision (P < 0.01).Conclusions After treatment

  18. Current progresses of experimental models of amblyopia and clinical therapeutic%弱视的实验研究及临床治疗展望

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    李少敏(综述)

    2014-01-01

    弱视是一种儿童早期由于异常的视觉经历如斜视,屈光参差,视觉剥夺等导致的皮层性视觉损害,因而,只有理解了其发病的神经机制,才可能提出有效的治疗。一般观念认为弱视只有在儿童期治疗才有效,而成人的弱视基本无法治愈,但是近年来随着对弱视发病机制的分子生物学及神经电生理的研究,尤其是对视觉皮层发育可塑性的细胞间交流及细胞内分子信号通路的认识,拓展了人们对弱视病理的知识,因而也成功地通过恢复成年期的可塑性改善了成年弱视的视力。本文介绍了视觉发育可塑性的进展,就近年在增强成年可塑性途径如改变神经兴奋性与抑制性的平衡、细胞外基质、丰富环境及表观遗传学修饰等作了介绍,以其对弱视的病理机制,尤其对成人弱视的治疗有更深入的认识。%Amblyopia is a form of cerebral visual impairment caused by abnormal visual experience ( e.g., strabismus, anisometropia, deprivation) during early childhood. It is essential to understand the neural mechanism of amblyopia in order to devise novel therapeutic strategies. Although previous concepts of amblyopia is an untreatable pathology in adults, recent data deepen our knowledge of the factors involved in the intercellular communication and intracellular signaling that mediate experience-dependent plasticity in the developing visual cortex. Successful en-hancement of adult plasticity has been achieved by altering the excitation to inhibition balance;extracellular matrices;environmental enrichment and epigenetic modification. In this review, I describe current concepts of brain plasticity and the established mechanisms of amblyopia, and their implications for novel therapeutic strategies, these may hold the best hope for success in the fight against amblyopia.

  19. A comparison of the visual status of dyslexic and non-dyslexic schoolchildren in Durban, South Africa

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    S. O. Wajuihian

    2011-12-01

    Full Text Available Background:   Reading difficulties constitute an impediment to the learning process and in the educational achievement of a child. Consequently, several studies examined the visual status of dyslexic children in the Caucasian populations. Such studies are lacking in the African populations.Aim: To determine the prevalence of vision defects and investigate if there is an association between dyslexia and vision in a South African population of dyslexic school children.  Methods:  This comparative study assessed the visual function of 62 children (31 dyslexic and 31 normally-reading children, mean age 13 ± 1.42 years and 11.90 ± 0.93 years respectively. The participants were matched for gender, race and socio-economic status. The visual functions evaluated and the techniques used were: visual acuity (LogMAR acuity chart, refraction (static retinos-copy, ocular alignment (cover test near point of convergence (RAF rule, accommodation facility (± 2 D flipper lenses, amplitude of accommodation (push-up method relative accommodation(trial lenses accommodation posture (monocular estimation technique and vergence reserves (prism bars. Results:   In the following, results are  provided for the dyslexic versus control:  Refractive errors: (hyperopia 6.5% vs 3%, (myopia 6.5% vs 6.5%, (astigmatism 10% vs 13%, (anisometropia 6.5% vs 6.5% (amblyopia 6.5% vs 0%, (remote NPC 33% vs 48% (esophoria at near 3%  vs 0% (exophoria at near 9.5% vs 0%, (accommodative infacility at near  54% vs 33%, lag of accommodation 39.28% vs 41,93%,  (poor positive fusional amplitude at near, 25% vs 16%. Only the binocular accommodative facility at near was significantly associated with dyslexia (p=0.027. Conclusion: The prevalence of vision defects was similar between the dyslexic and non-dyslexic participants, which suggest that an association between dyslexia and vision variables investigated, cannot be inferred.  This study provides a research perspective on the

  20. Performance of Spot Photoscreener in Detecting Amblyopia Risk Factors in Chinese Pre-school and School Age Children Attending an Eye Clinic.

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    Yajun Mu

    Full Text Available To evaluate the effectiveness of Spot photoscreener in detecting amblyopia risk factors meeting 2013 the American Association of Pediatric Ophthalmology and Strabismus (AAPOS criteria in Chinese preschool and school-age children.One hundred and fifty-five children (310 eyes, aged between 4 to 7 years (5.74 ± 1.2 years underwent complete ophthalmologic examination, photoscreening, and cycloplegic retinoscopy refraction. The agreement of the results obtained with the photoscreening and retinoscopy was evaluated by linear regression and Bland-Altman plots. The sensitivity and specificity of detecting amblyopia risk factors were calculated based on the AAPOS 2013 guidelines. The overall effectiveness of detecting amblyopia risk factors was analyzed with Receiver Operating Characteristic (ROC curves.The mean refractive errors measured with the Spot were: spherical equivalent (SE = 0.70 ± 1.99 D, J0 = 0.87 ± 1.01 D, J45 = 0.09 ± 0.60 D. The mean results from retinoscopy were: SE = 1.19 ± 2.22 D, J0 = 0.77 ± 1.00 D, J45 = -0.02 ± 0.45 D. There was a strong linear agreement between results obtained from those two methods (R2 = 0.88, P<0.01. Bland-Altman plot indicated a moderate agreement of cylinder values between the two methods. Based on the criteria specified by the AAPOS 2013 guidelines, the sensitivity and specificity (in respective order for detecting hyperopia were 98.31% and 97.14%; for detecting myopia were 78.50% and 88.64%; for detecting astigmatism were 90.91% and 80.37%; for detecting anisometropia were 93.10% and 85.25%; and for detection of strabismus was 77.55% and 88.18%.The refractive values measured from Spot photoscreener showed a moderate agreement with the results from cycloplegic retinoscopy refraction, however there was an overall myopic shift of -0.49D. The performance in detecting individual amblyopia risk factors was satisfactory, but could be further improved by optimizing criteria based on ROC curves.

  1. Analyze of the accommodative response in myopia anisometropes%近视性屈光参差者双眼调节反应的研究

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    徐丹; 姜俭; 阎静; 吕帆; 瞿佳

    2009-01-01

    Objectives This study is designed to analyze the accommodative hysteresis, accommodative responses between two eyes of anisometropes. The difference of the shape and slope of the accommodative response curves under closed-loop state is evaluated. A comparison study between emmetropes and anisometropes was assessed as well. Methods It was a ease-control study. Forty volunteers, (age from 20 to 31 years)participated in the research. 20 subjects had emmetropia(spherical equivalent + 0.37D to -0.25D in both eyes), 20 subjects bad anisometropia with spherical power difference ranging from 2. 50D to 7.00D between their two eyes. Accommodation taken by objective methods: RE and accommodative response (AR) to 1.00D, 2.00D, 3.00D, 4.00D stimulus were measured objectively by WV-500 binocular infrared optometer (Grand Seiko Co. Japan). The slope of the AR/AS was calculated and compared between different groups. Results Under closed-loop state, the higher refractive error eye of anisemetropia had most accommodation lag followed by lower eye and emmetropic eye. In stimulus of 3.00D and 4. 00D, the differences between higher eye and emmetrepic eye were significant (t= 2.055, 2.410; P 0. 05). But the slopes of higher refractive error were lower than that of emmetropoes (t = 2. 550, P 2.50 D且0.05),但屈光参差高度数眼的斜率低于正视眼的AR/AS斜率(t-2.550,P<0.05).结论 屈光参差者两眼调节反应不等,高度眼表现出更多的调节滞后.屈光参差者双眼在等量调节刺激下,表现为不等量的调节反应,高度数眼要产生相同的调节反应,需要更多的调节刺激.可能与调节中枢的控制增益不同有关,也可能与"睫状肌一晶状体"系统调节反应阈值较高有关.(中华眼科杂志,2009,45:612-615)

  2. Surgical Results in Cases of Sensory Strabismus

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    Ayfle Yeflim Oral

    2011-08-01

    Full Text Available Purpose: To determine horizontal deviation type and to evaluate the correlation between deviation type/etiology and surgical results for sensory strabismus. Patients and Methods: The reports of 29 patients operated for sensory strabismus (12 female, 17 male whose mean age was 22.17±11.52 (range: 4-57 years were evaluated retrospectively. Sixteen cases (55.2% had exotropia (XT and 13 cases (44.8% had esotropia (ET. Etiologies, ages during surgeries, and preoperative/postoperative deviation amounts were noted for the total of the patients as well as for ET and XT groups separately. The results for ET and XT groups were compared statistically using t test. The mean follow-up time was 4.27±3.5 years (range: 4 months-12 years and deviation in ±10 prism diopters (PD in the last visit was considered as success. Results: Etiologies in all cases examined were as follows: anisometropia in 13 (44.8%, trauma in 10 (34.5%, congenital cataracts in 2, and congenital glaucoma, keratoconus, choroidal coloboma, and hypoplastic optic disc in one case each. The visual acuity of the squinting eyes ranged from no light perception to 0.8 logMAR. The mean preoperative deviation was 46.24±19.29 PD, and the mean postoperative deviation decreased to 9.55±11.86 PD in the last visit. When the ET and XT groups were compared, the congenital causes were more common in the ET group (30.75% compared to the XT group (6.25%, otherwise, there was no statistically significant difference in terms of mean age, preoperative and postoperative deviation amounts and follow-up time between the two groups (p>0.05. In contrast, while the surgical success rate was found to be 75.9 % for all cases and 87.5% for the XT group, it was 61.5% for the ET group. Discussion: Despite the deep amblyopia in sensory strabismus, satisfactory surgical results are achieved; nevertheless, the success may be more limited in sensory esotropia particularly due to congenital causes. (Turk J Ophthalmol 2011

  3. Detecção de ambliopia, ametropias e fatores ambliogênicos em comunidade assistida por Programa da Saúde da Família no Rio de Janeiro, Brasil Amblyopia, ametropia and amblyogenic factors detection in a community assisted by Health Family Program in Rio de Janeiro, Brazil

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    Arlette Machado Oliveira

    2010-10-01

    Full Text Available OBJETIVOS: Determinar a prevalência dos fatores ambliogênicos e ambliopia na área adscrita do Programa Saúde da Família (PSF da Lapa (RJ e, estimar na mesma área a sensibilidade e especificidade entre métodos de medida de acuidade visual (tabelas ETDRS e LEA em crianças pré-escolares. MÉTODOS: Estudo transversal de 93 crianças entre três a seis anos da área adscrita do PSF Lapa, RJ. Todas as crianças foram submetidas à avaliação oftalmológica completa que incluiu: anamnese dirigida, ectoscopia, medida da acuidade visual com tabela de ETDRS e LEA de forma duplo cega, reflexo vermelho, teste de Titmus, refração objetiva sob cicloplegia, refração subjetiva, avaliação da motilidade ocular, biomicroscopia do segmento anterior, fundoscopia sob midríase. Os dados foram coletados na Policlínica Ronaldo Gazolla, da Universidade Estácio de Sá. RESULTADOS: A prevalência dos fatores ambliogênicos foi encontrada e distribuída em: 8,4 % de estrabismo; 11,86% de anisometropia e 15,2% de ametropia. O teste de acuidade visual ETDRS apresentou sensibilidade de 100% e especificidade de 18% para detecção de ambliopia. O teste de acuidade visual LEA apresentou sensibilidade de 100% e especificidade de 30,9% para detecção de ambliopia. CONCLUSÃO: Ambas tabelas ETDRS e LEA podem ser usadas para a triagem de ambliopia porque tiveram 100% de sensibilidade. A especificidade foi maior para a tabela LEA. Porém ainda em nível baixo. Portanto, há necessidade da complementação com o exame oftalmológico completo para confirmar e ratificar a presença de fatores ambliogênicos em pacientes triados positivamente. A triagem visual feita pelos Agentes Comunitários de Saúde pode identificar crianças com distúrbios visuais, referenciando para exame oftalmológico completo; em um grupo etário onde a resolução dos problemas visuais se apresenta como prioridade. O Programa de Saúde da Família pode ser utilizado para avaliar o estado de

  4. Detecção de ambliopia, ametropias e fatores ambliogênicos em comunidade assistida por Programa da Saúde da Família no Rio de Janeiro, Brasil Amblyopia, ametropia and amblyogenic factors detection in a community assisted by Health Family Program in Rio de Janeiro, Brazil

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    Arlette Machado Oliveira

    2010-04-01

    Full Text Available OBJETIVO: Estimar a prevalência dos fatores ambliogênicos e ambliopia na área adscrita do Programa Saúde da Família (PSF da Lapa (RJ e estimar na mesma área a sensibilidade/especificidade entre os métodos de medida da acuidade visual (tabelas ETDRS e LEA para triagem em crianças pré-escolares (três a seis anos. MÉTODOS: Estudo transversal de 93 crianças entre três e seis anos da área adscrita do PSF Lapa, RJ. Todas as crianças foram submetidas a avaliação oftalmológica completa que incluiu: anamnese dirigida, ectoscopia, medida da acuidade visual com tabela de ETDRS e LEA de forma duplo cega, reflexo vermelho, teste de Titmus, refração objetiva sob cicloplegia, refração subjetiva, avaliação da motilidade ocular, biomicroscopia do segmento anterior, fundoscopia sob midríase.Os dados foram coletados na Policlínica Ronaldo Gazolla, da Universidade Estácio de Sá. RESULTADOS: A prevalência dos fatores ambliogênicos foi encontrada e distribuída em: 8,4% de estrabismo, 11,86% de anisometropia e 15,2 % de ametropia. O teste de acuidade visual ETDRS apresentou sensibilidade de 100 % e especificidade de 18% para detecção de ambliopia. O teste de acuidade visual LEA apresentou sensibilidade de 100% e especificidade de 30,9 % para detecção de ambliopia. CONCLUSÃO: Ambas tabelas ETDRS e LEA podem ser usadas para a triagem de ambliopia porque tiveram 100% de sensibilidade. A especificidade foi maior para a tabela LEA. Porém, ainda em nível baixo. Portanto, há necessidade da complementação com o exame oftalmológico completo para confirmar e ratificar a presença de fatores ambliogênicos em pacientes triados positivamente. A triagem visual feita pelos agentes comunitários de saúde pode identificar crianças com distúrbios visuais, referenciando para exame oftalmológico completo; em um grupo etário onde a resolução dos problemas visuais se apresenta como prioridade. O Programa de Saúde da Família pode ser

  5. Lente de contato em crianças: aspectos epidemiológicos Contact lens in children: epidemiological aspects

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    André Luiz Alves Salame

    2008-06-01

    Full Text Available OBJETIVO: Traçar o perfil epidemiológico de crianças encaminhadas para adaptação de lente de contato. MÉTODOS: Foi realizado estudo retrospectivo de pacientes registrados no Setor de lente de contato da Universidade Federal de São Paulo. Os pacientes com até 12 anos de idade foram avaliados quanto ao sexo, idade, diagnóstico, indicação e tipo de lente de contato testada na primeira consulta. RESULTADOS: Dos 73 prontuários avaliados, 34 (46,6% pertenciam a crianças do sexo masculino e 39 (53,4% a crianças do sexo feminino. A idade variou de 2 a 12 com média de 10,2 e desvio-padrão de 2,42 anos. O diagnóstico mais encontrado foi afacia em 16 (21,9% crianças, seguido de ceratocone em 14 (19,1%, leucoma em 11 (15%, anisometropia em 10 (13,7%, ametropia em 9 (12,3%, astigmatismo irregular em 7 (9,5% e ectopia lentis em 4 (5,4%. Uma criança era alta míope (1,3% e outra emétrope (1,3% que possuía desejo de usar lente de contato estética. Em relação às indicações, 52 (71,2% pacientes tinham indicação médica, 9 (12,3% indicação óptica e 12 (16,4% indicação cosmética. Foram testadas lentes em 103 olhos sendo as mais testadas a rígida gás permeável esférica em 43 (41,7%, a gelatinosa esférica em 41 (39,8% e a gelatinosa cosmética em 11 (10,6%. CONCLUSÃO: O perfil epidemiológico dos usuários de lente de contato nessa faixa etária tem como diagnóstico mais prevalente a afacia, a indicação mais freqüente a de ordem médica e a lente mais testada a rígida gás permeável esférica.PURPOSE: To describe the epidemiology of children submitted to contact lens fit. METHODS: Retrospective study of 73 children that had been submitted to contact lens fit at the "Universidade Federal de São Paulo". This study analyzed sex distribution, age, diagnosis, indications and contact lens fitted at first examination. RESULTS: 34 children (46.6% were male and 39 (53.4% female, aged between 2 and 12 years with mean of 10.2 and

  6. Phacoemulsification and intraocular lens implantation in the treatment of monocular cataract in young and middle-aged patients%超声乳化术治疗中青年单眼白内障临床分析

    Institute of Scientific and Technical Information of China (English)

    周沐瑶; 窦晓燕

    2014-01-01

    -males, were included in this study .Ages were between 21~48 years old, averaged at 37.5.Preoperative visual acuity was below 0.4 in the cataract eye and above 0.6 in the fellow eye for all patients except that in 1 patient visual acuity was 0.6 in cataract.Pretreatment conditions included hyperopia (3 eyes), high myopia (9 eyes, among which 1 eye received exci-mer laser therapy, and 3 eyes had astigmatism larger than -1.00 D), diabetes mellitus (3 patients), uveitis (3 eyes), trauma (2 eyes), and history of vitrectomy (1 eye).Patients received routine examinations and IOL power calculation . Phacoemulsification was performed followed by the implantation of intraocular lens , including 3 AcrysofToric IOLs, under local anesthesia .In addition, seven patients were prescribed with contact lens for the fellow eye , and 2 patients received la-ser in situ keratomileusis(LASIK) in the fellow eye.Results All patients obtained improved visual acuity with varying de-grees.Postoperative visual acuity of those that had no obvious predisposing causes reached 1.2.AcrysofToric IOLs that were implanted in 3 patients remained stable axis after 6 months.Patients who have suffered severe anisometropia gained better binocular vision with contact lens wearing or excimer laser therapy on the fellow eyes .Conclusions The implantation of in-traocular lens after phacoemulsification in the treatment of young and middle-aged monocular cataract patients is an effective and safe method.Indications for the surgeryshould be personalized according to patient 's age, refraction of the fellow eye, and the demands from work and daily life .Severe anisometropia should be corrected via contact lens wearing or excimer la-ser therapy in the fellow eye in order to restore binocular vision and to improve the quality of life .

  7. Resultados do tratamento da ambliopia com levodopa combinada à oclusão Results of amblyopia treatment with levodopa associated with occlusion therapy

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    Edson Procianoy

    2004-10-01

    Full Text Available OBJETIVO: Verificar a melhora da acuidade visual com levodopa/benzerazida combinada à oclusão parcial e seguida por oclusão total, em pacientes com ambliopia considerada irreversível. MÉTODOS: Realizou-se estudo experimental aberto, envolvendo 37 pacientes entre 7 e 40 anos de idade, com ambliopia por estrabismo ou anisometropia, durante 9 semanas. Todos os pacientes foram tratados com levodopa (0,70 mg/kg/dia e benzerazida 25% associada à oclusão de 4 horas/dia do olho dominante por 5 semanas e, nas 4 semanas seguintes foi realizada somente a oclusão total (24 h do olho dominante. A acuidade visual foi medida na tabela do ETDR (Early Treatment Diabetic Retinopathy com escala logMAR (logaritmo do mínimo ângulo de resolução antes de iniciar o tratamento e após 1, 3, 5 e 9 semanas de tratamento. As adesões ao tratamento de oclusão e a ingesta do me-dicamento foram verificadas por meio de questionário e pela contagem das cápsulas. Os efeitos adversos foram avaliados por exame clínico e questionário. RESULTADOS: Após 9 semanas de tratamento, a acuidade visual média melhorou em logMAR de 0,58 ± 0,16 para 0,23 ± 0,16 (melhora de 4 linhas na tabela ETDR. CONCLUSÃO: Levodopa, na dose de 0,70 mg/kg/dia, é bem tolerada e associada à oclusão produz melhora significativa na acuidade visual de pacientes com ambliopia considerada irreversível.PURPOSE: To evaluate visual acuity improvement with levodopa/benzerazide associated with partial occlusion and followed by total occlusion therapy in patients with amblyopia considered irreversible. METHODS: A 9-week experimental open study was performed involving 37 patients, between 7 and 40 years old, with strabismic and/or anisometropic amblyopia. All patients were treated with levodopa (0.70 mg/kg/day and 25% benzerazide associated with 4-hour/day occlusion of the dominant eye for 5 weeks. In the last 4 weeks, only the total occlusion (24 h of the dominant eye was performed. Visual acuity

  8. Short-term variation of autorefraction in Diabetic Macular Edema (DME *

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    A. Y. Sukha

    2007-01-01

    paper provides some preliminary data to suggest that diabetic subjects with DME display greater short-term variation of refractive behaviour when compared to diabetic subjects without DME. Secondly, in diabetic subjects withDME, eyes with the more severe DME or worse VA also display greater variation of refractive status. However, there seemed to be no distinctive or obvious pattern to the type of variation.In addition, a suitable statistic in terms of a Cubic Root Difference (CRD was introduced in this study to compare inter-ocular ellipsoidal volumes. This statistic is also useful for comparing variances between eyes, or between means for groups of eyes, and could be used in studies involving anisometropia,  et cetera. Nevertheless, this study suggests that further investigation remains necessary before autorefraction can be used effectively in the early diagnosis, monitoring, and assessment of eyes with diabetic-related complications to the macular regions. 

  9. Immediate versus Delayed Sequential Bilateral Cataract Surgery: A Systematic Review and Meta-Analysis.

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    Monali S Malvankar-Mehta

    Full Text Available Immediately sequential bilateral cataract surgery (ISBCS, the cataract surgery that is performed in both eyes simultaneously, is gaining popularity worldwide compared to the traditional treatment paradigm: delayed sequential bilateral cataract surgery (DSBCS, the surgery that is performed in each eye on a different day as a completely separate operation. ISBCS provides advantages to patients and patients' families in the form of fewer hospital visits. Additionally, patients enjoy rapid rehabilitation, lack of anisometropia - potentially reducing accidents and falls, and avoid suboptimal visual function in daily life. The hospital may benefit due to lower cost.To perform a systematic review and meta-analysis to evaluate ISBCS and DSBCS.Databases including MEDLINE, EMBASE, BIOSIS, CINAHL, Health Economic Evaluations Database (HEED, ISI Web of Science (Thomson-Reuters and the Cochrane Library were searched.Not applicable.Literature was systematically reviewed using EPPI-Reviewer 4 gateway. Meta-analysis was conducted using STATA v. 13.0. Standardized mean difference (SMD and 95% confidence intervals (CI were calculated and heterogeneity was assessed using I2 statistics. Fixed-effect and random-effect models were computed based on heterogeneity. Meta-analysis was done by instrument used to calculate utility score.In total, 9,133 records were retrieved from multiple databases and an additional 128 records were identified through grey literature search. Eleven articles with 3,657 subjects were included for analysis. Our meta-analysis results indicated significant improvement in post-operative utility score using TTO, EQ5D, HUI3, VF-7, and VF-14 and a non-significant improvement using Catquest questionnaire for both surgeries. For ISBCS versus DSBCS, utility-specific fixed-effect model provided an overall SMD of the utility score using the TTO method as 0.12 (95% CI: -0.15, 0.40, EQ5D as 0.14 (95% CI: -0.14, 0.41, HUI3 as 0.12 (95% CI: -0.15, 0.40, VF

  10. Clinical observation of rigid gas permeable contact lenses for children with high myopia%高度近视儿童配戴硬性透气性角膜接触镜临床观察

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    杨积文; 卜立敏; 纪惠芳; 苑苗苗; 张悦

    2012-01-01

    Objective To investigate the effect of rigid gas permeable contact lens (RGPCL) for high myopia in children less than six years old for 2 years. Methods With guidance of corneal topography, 16 children (32 eyes) ranging from 3 to 6 years old with high myopia were fitted into RGPCL. RGPCL condition and adaption were observed. The best glass and RGPCL corrected vision were compared. All children were followed up for 2 years. The incidence of complications, diopter and improvement of vision were observed. Results There was statistical difference in corrected vision between wearing glasses and RGPCL( t = - 4. 558 ,P < 0. 05), also in corrected vision before and at 2 years after wearing glasses( t = 6.027 ,P < 0. 05). After 2 years, the diopter increased ( -0.17 ± 0. 42) D,and the ocular length increased ( - 0. 07 ± 0. 02) mm. All the children were worn glasses successfully once. These all can see and play normally at 5 minutes after wearing try-in glasses, and worn all the day within one week. During following up time, all the children can wear RGPCL all the day except one child for theparents having no time to help him wearing glasses. Parents had to clean glasses and help children to wear. Five children could wear glasses independently. No severe complication was observed, as corneal neovascularization, corneal abrasion, keratohelcosis and so on. Conclusion RGPCL is safe and effective for high myopia and myopic anisometropia in children.%目的 探讨6岁以下高度近视儿童配戴硬性透气性角膜接触镜(rigid gas permeable contact lens,RGPCL)2 a的临床应用效果.方法 在角膜地形图指导下对16例(32眼)3~6岁高度近视儿童进行RGPCL配戴,观察患儿的RGPCL配戴和适应情况,比较最佳框架眼镜和RGPCL矫正视力.随访2 a观察并发症的发生情况、屈光度发展及视力提高情况.结果 配戴框架眼镜矫正视力与RGPCL比较差异有统计学意义(t=-4.558,P<O.05);配戴RGPCL 2 a前后矫正视

  11. New progress in the treatment of amblyopia and related binocular visual impairment%弱视及弱视相关双眼视功能损害治疗的新进展

    Institute of Scientific and Technical Information of China (English)

    李蕾; 付晶

    2016-01-01

    人眼在视觉发育期由于单眼斜视、未矫正的屈光参差、高度屈光不正及形觉剥夺引起的单眼或双眼最佳矫正视力低于相应年龄的视力为弱视;或双眼视力相差2行及以上,视力较低眼为弱视。弱视在视觉敏感期给予正确治疗可治愈,然而一旦错过治疗时机则会造成终生视力低下;且弱视还会影响双眼视觉功能。因此,弱视的治疗一直是眼科研究的热点问题。目前,弱视的主要方法包括屈光矫正、遮盖疗法、药物治疗、压抑疗法、手术治疗(针对形觉剥夺性弱视)、综合治疗等。近年来,双眼视功能的重建在弱视治疗评价中也逐渐受到重视。本文中笔者在回顾国内外相关文献的基础上,对弱视的治疗方法及最新进展做一综述。%The best corrected visual acuity of monocular or binocular vision in patients with amblyopia is lower than that in normal eyes .It is in visual development period ,as a result of the monocular strabismus,uncorrected anisometropia, highly refractive errors, form deprivation induced.In addition, binocular vision is a difference of 2 lines, low vision eye is amblyopia .Amblyopia in the visual sensitive period to give the correct treatment can be cured , but once missed the opportunity of treatment will cause lifelong amblyopia;and the amblyopia will affect the binocular visual function .Therefore , the treatment of amblyopia has been a hot issue in the Department of Ophthalmology .At present, the main methods of amblyopia including refractive correction , cover therapy , medicine therapy , depression therapy , surgical treatment ( for form deprivation amblyopia ), comprehensive treatment, and so on.In recent years, the reconstruction of binocular visual function has been paid more and more attention in the treatment of amblyopia .On the basis of reviewing domestic and foreign literatures , the author reviewed the treatment methods and the latest

  12. A cross-sectional survey on refractive errors in students 4-18 years old in Guanxian county,Shandong province%山东省冠县4~18岁学生屈光不正横断面研究

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    吴建峰; 毕宏生; 胡媛媛; 吴慧; 孙伟; 吕太亮; 王兴荣

    2014-01-01

    Objective To examine the prevalence of refractive errors among preschool children and schoolchildren in Guanxian county,Shandong province.Methods Using a random cluster sampling in a cross-sectional school-based study design,children ranging in age from 4 to 18 years were selected from kindergartens,primary schools,and junior and senior high schools in Guanxian county.All children underwent a complete ocular examination including measurement of uncorrected (UCVA) and best corrected visual acuity (BCVA),auto-refractometry under cycloplegia and ophthalmic examination.The prevalence rates of refractive error and its association with age and gender were analyzed by a bivariate regression model.Results Of 3 112 eligible children,cycloplegic refraction was completed on 3 111 and the visual acuity of 3 094 was successfully tested.The overall prevalence of myopia was 31.3%(95%CI:29.7%-33.0%).Myopia was associated with older children [OR:1.45 (95%CI:1.41-1.50); P<0.01],female gender [OR:1.45(95%CI:1.41-1.50); P<0.01] and children in urban areas [OR:2.54 (95%CI:2.11-3.07) ; P<0.01].The prevalence of high myopia,astigmatism and anisometropia was 1.4% (95%CI:1.0%-1.8%),32.4% (95%CI:30.8%-34.0%) and 6.2% (95%CI:5.4%-7.1%),respectively.All prevalences were associated with older children (P<0.01) but not gender (P>0.05).The prevalence of astigmatism and anisometropia was also associated with children in urban areas (P<0.01).The overall prevalence of hyperopia was 8.2%(95%CI:7.2%-9.2%),and the trend decreased with age [OR:0.72(95%CI:0.68-0.76); P<0.01].UCVA was 20/40 or worse in the better eye in 675(21.8%) children,and 20/200 or worse in the better eye in 85(2.7%) children.UCVA≤20/40 in one or both eyes was found in 880(28.4%) children,with undercorrected refractive error as the cause in 837(95.1%) children.Conclusion Visual impairment in students 4-18 years of age in Guanxian county was mainly attributed to

  13. Effect of myopic defocus on static visual acuity and dynamic visual acuity%近视性离焦对静态视力和动态视力的影响

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    邓军; 保金华; 陈浩

    2011-01-01

    Background Researches have suggested that the defocus can induce the change of static visual acuity,but whether it produce influence on dynamic visual acuity is not clear.Objective This study was to investigate the impact of myopic defocus on static visual acuity and dynamic visual acuity and explore the essential difierence between static visual acuity and dynamic visual acuity. Methods Forty volunteers were enrolled in this trial.including 20 adults with the age of 27.4±1.64 years and 20 children with the age of 11.70+1.49 years.All the eyes of subjects received regular examined to excluded the eye disease with the best corrected vision of ≥1.0 D,astigmatism of ≤0.75 D and anisometropia <1.50 D.+1.00 D,+1.50 D,+2.00 D,+2.50 D slasses were ware respectively for the defocus on the foundation of full correction.Dynamic visual acuity was inspected by using selfmade DVA-I training software.and static visual acuity wag tested by static visual acuity chart (Precision Vision,CAT.NO.2125).This clinical trial complied with the Helsinki Declaration and obtained the approval of Ethic Committee of Wenzhou Medical College.Written informed consent was received from each individual prior to the protocol. Results The dynamic and static visual acuities were gradually decreased with the elevation of defocus (F=506.907,P=0.000).No significant differences were found between static visual acuity and dynamic visual acuity in adult or children at various defocus(P>0.05).The regression linear analysis showed that a positive correlation between static visual acuity with defoeus(R2=0.819,t=26.72,P=0.000) or dynamic visual acuity with defoeus(R2=0.826,t=27.42,P=0.000).The slope and intercept between defocus with static visual acuity were steeper than that between defocus and dynamic visual acuity (slope:F=34.18,P=0.000;intercept:F=1005.56,P=0.001). Conclusion The effect of defocus on static visual acuity is different from that of dynamic visual acuity.It could be speculated that

  14. Effect of form deprivation time on main refractive parameter in congenital cataract%先天性白内障形觉剥夺时间对眼主要屈光参数的影响

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    栾国刚; 严涛; 谌金金; 熊莎; 章艳

    2012-01-01

    Objective To evaluate the effect of form deprivation time on the main refractive parameter in congenital cataract. Methods Forty-eight congenital cat-aract patients(48 eyes) aged from 6 months to thirty-five years were chosen,the subjective refraction was determined,and the retinoscopy was performed in patients,who unable to receive the subjective refraction examination. Based on form deprivation time,the patients were divided into from 0 year to 4 years group(13 eyes), from 4 years to 8 years group(18 eyes) and more than 8 years group(17 eyes) ,the binocular axis length and corneal curvature were measured. The amblyopia was defined as the best corrected visual acuity below normal vision, or the difference of binocular best corrected visual a-cuity equal to or more than two lines. Results In from 0 year to 4 years group and from 4 years to 8 years group,the difference between binocular axial length was not sig-nificant( P = 0.547,0.563), and the deprivation time was not related with the difference in binocular axial length, which were (0. 92 ±0.41) mm and (1. 64 ± 1. 49) mm (P = 0.890,0. 703); The difference of binocular corneal curvature had also no significant difference in all deprivation time points (all P > 0.05). In more than 8 years group, there was significant difference in difference of binocular axis length (P 0.05). The absolute value of binocular spherical equivalence difference (3.66±3.00)D was positive related with the absolute value of axial length difference (2.23 ± 1.46) mm in 42 eyes (r = 0.782 ,P < 0.01). Conclusion The deprivation form at early stage in congenital cataract patients has no effect on axial length,and its main effect is forming the amblyopia. The anisometropia in single eye with congenital cataract is mainly caused by prolonged ocular axis.%目的 评价先天性白内障形觉剥夺时间对眼屈光系统主要参数的影响.方法 选取单眼先天性白内障患者48例,年龄(6个月~35岁);术前综合验光仪进