间歇性外斜视患者双眼视功能的研究进展

间歇性外斜视是儿童常见的外斜视类型，其患病率处于各种共同性外斜视首位，但关于其病因、发病机制、治疗最佳时机等仍存在争议，笔者将依据近几年的研究结果，针对间歇性外斜视的临床表现、疾病分型、视功能特点和控制程度等方面进行概述。     

Influence of Accommodative Lag upon the Far-Gradient Measurement of Accommodative Convergence to Accommodation Ratio in Strabismic Patients

Purpose

To determine the influence of the lag of accommodation (LOA) on the accommodative convergence to accommodation (AC/A) ratio measured by the far-gradient method in strabismic patients.

Methods

The AC/A ratio was measured with a distance target viewed with and without ?3.00 diopter (D) addition lenses in 63 patients with different types of strabismus (age range, 7–34 years; range of strabismic angle, ?60 to +40 prism diopters; refractive error range, ?7.33 to +6.63?D). The LOA for the same lens was measured with an open-view-type autorefractometer. The stimulus AC/A ratio and the AC/A ratio adjusted by the individually measured LOA (adjusted AC/A ratio) were compared.

Results

The mean ± SD of the LOA to the ?3.00?D lenses was 1.06 ± 0.43?D. The mean adjusted AC/A ratio was 41% greater than the stimulus AC/A ratio. The LOA differed widely among patients (0.13 to 2.14?D), and a large LOA tended to appear in myopic or young patients.

Conclusions

The AC/A ratio obtained using the conventional far-gradient method is significantly biased by the LOA, and thus does not always represent the actual relationship between accommodation and vergence control systems.?Jpn J Ophthalmol 2006;50:438–442 © Japanese Ophthalmological Society 2006     

Accommodative Anomalies in a Sample of Black High School Students in South Africa

Purpose: Accommodative anomalies cause asthenopia and affect student reading efficiency and academic performance. The aim of conducting this study was to determine the prevalence and distribution of accommodative anomalies (insufficiency, excess and infacility) in relation to demographic variables (sex, age, school grade level and study location).

Methods: Study participants comprised 1,211 children (481 male and 730 female), with age range 13-19 years. Visual functions evaluated included refractive error, accommodative amplitude, accuracy, facility and relative accommodation.

Results: A total of 242 participants (20.2%) had accommodative anomalies. Prevalence estimates were; accommodative infacility 12.9% (95% confidence interval, CI, 10.9-14.7%), accommodative insufficiency 4.5% (95% CI 3.4-5.8%) and accommodative excess 2.8% (95% CI 1.9-3.8%). There were no significant differences based on sex, school grade level or study site, except in the prevalence of accommodative infacility, which was significantly higher in the younger grade level than the older (P=0.027).

Conclusion: The study fills a gap in the literature in providing data on predominantly black South African students. The prevalence estimates for accommodative insufficiency and excess found in the sample studied are relatively low, while that of accommodative infacility is high. Accommodative anomalies were not markedly associated with demographic variables except for the prevalence of accommodative infacility, which was significantly higher in the younger grade level than the older. Identification and referral are important steps towards diagnosis and treatment of accommodative anomalies. Future studies on differences in prevalence of accommodative anomalies among different racial populations will be relevant.     

Asthenopia in Schoolchildren,Orthoptic and Ophthalmological Findings and Treatment

The aim of this study was to describe the orthoptic and ophthalmological findings in schoolchildren with asthenopia, to correlate them with asthenopic symptoms and to evaluate the effect of treatment. One hundred and twenty schoolchildren, aged 6–16 years, were included in the study. They were all referred by school nurses, for asthenopic symptoms. An orthoptic and ophthalmological assessment was performed. The main diagnoses were accommodative insufficiency, convergence insufficiency, refractive errors, and latent strabismus. Reading glasses could help 98% of the schoolchildren with reduced accommodation, and 94% of the children with refractive errors and heterophorias were helped with appropriate spherical, cylindrical and prism correction. Convergence exercise reduced the symptoms in all patients with convergence insufficiency. Ninety-three percent of all 120 schoolchildren were symptom free 3–6 month after treatment had started. By an orthoptic and ophthalmological examination abnormalities in schoolchildren with asthenopia related to visual problems can be identified. Most of the children were relieved from their symptoms by giving adequate glasses, convergence exercises and surgery.     

调节聚散系统交互作用的相关性

目的：探讨正视眼和早发性近视眼刺激性调节性集合/调节比值（AC/A值）、刺激性集合性调节/集合比值（CA/C值）、反应性AC/A以及反应性CA/C之间的差异及相互关系。方法：病例对照研究。选取 2016年10月至2017年1月在温州医科大学附属眼视光医院视光门诊就诊的9～14岁早发性近视患者 27例为早发性近视组,另选取20例正视者作为正视组,在双眼视状态使用精工自动红外验光仪和改良式Thorington法分别测量25 cm处5个调节刺激水平和6个聚散刺激水平下的调节反应和隐斜量,计算2组的刺激性AC/A、刺激性CA/C、反应性AC/A以及反应性CA/C值。数据采用t检验和Pearson 相关性分析进行统计分析。结果：正视组、早发性近视组的反应性AC/A分别为（4.07±1.47）Δ /D、（5.13±1.95）Δ /D,差异有统计学意义（t=2.12,P=0.04）。正视组、早发性近视组的刺激性AC/A和反应性AC/A值之间均呈正相关（正视组：r=0.903,P<0.001;早发性近视组：r=0.880,P<0.001）。正视组的反应性AC/A和反应性CA/C呈负相关（r=-0.450,P=0.04）,早发性近视组这2个参数间无相关性（r=-0.367,P=0.06）。结论：早发性近视眼的反应性AC/A高于正视眼。AC/A和CA/C之间的负相关性只见于正视眼的反应性比率之间,提示单AC/A值不能全面评估调节系统和聚散系统之间的交互作用。     

汉语发展性阅读障碍儿童调节功能与眼位的研究

目的 探讨汉语发展性阅读障碍儿童与正常儿童调节功能与眼位各参数的变化,明确影响汉语发展性阅读障碍儿童视觉效率的关键视觉因素.方法 病例对照研究.选取天津市12所小学五年级学生1458名.根据识字量和瑞文智力的测验结果,筛选出98名汉语发展性阅读障碍儿童为试验组,随机选取年龄、性别、瑞文智力与之匹配的98名正常儿童为对照...     

The role of clinical diagnosis criteria on the frequency of accommodative insufficiency

AIM: To estimate and compare the frequency of accommodative insufficiency (AI) within the same clinical population sample depending on the type of clinical criteria used for diagnosis. Comparing the frequency within the same population would help to minimize bias due to sampling or methodological variability. METHODS: Retrospective study of 205 medical records of symptomatic subjects free of any organic cause and symptoms persisting despite optical compensation evaluated. Based on the most commonly clinical diagnostics criteria found in the literature, four diagnostics criteria were established for AI (I, II, III and IV) based on subjective accommodative tests: monocular accommodative amplitude two or more diopters below Hofstetter’s minimum value [15-(0.25×age)] (I, II, III, IV); failing monocular accommodative facility with minus lens, establishing the cut-off in 0 cycles per minute (cpm) (I) and in 6 cpm (II, III); failing binocular accommodative facility with minus lens, establishing the cut-off in 0 cpm (I) and in 3 cpm (II). RESULTS: The proportion of AI (95%CI) for criteria I, II, III and IV were 1.95% (0.04%-3.86%), 2.93% (0.31%-4.57%), 6.34% (1.90%-7.85%) and 41.95% (35.14%-48.76%) respectively, with a statistically significant difference shown between these values (χ2=226.7, P<0.001). A pairwise multiple comparison revealed that the proportion of AI detected for criterion IV was significantly greater than the proportion for the rest of the criteria (P-adjusted<0.05 in all cases). CONCLUSION: The prevalence of cases of AI within the same clinical population varies with the clinical diagnostic criteria selected. The variation is statistically significant when considering the monocular accommodative amplitude as the only clinical diagnostic sign.     

The Response AC/A Ratio: Differences Between Inducing and Relaxing Accommodation at Different Distances of Fixation

Purpose: To determine if there is a difference between the response AC/A ratios when measured using the gradient method at near and distance fixation with plus and minus lenses respectively in young adults with normal binocular single vision.

Methods: A repeated measures design was used. The accommodative response of the right eye was measured objectively using the Shin-Nippon SRW-5000 autorefractor (Grand Seiko Company, Fukuyama, Japan) (open view) at 33?cm with and without plus lenses (2DS or 3DS) and at 3.8 m with and without minus lenses (2DS or 3DS) dependent on the participants’ ability to obtain subjectively “clear” vision. The angle of deviation was measured using the alternate prism cover test at 33cm and 3.8m fixing with the right eye with the participant sat at the autorefractor. LogMAR 0.0 (6/6) was used for fixation. Response AC/A ratios were calculated.

Results: Twenty-five participants were examined; mean and standard deviation of their ages were 21.2?±?4.04 years. The mean and standard deviation of the near response AC/A ratios was 4.73?±?2.34/1 and at distance was 3.05?±?1.71/1. Pearson’s Product Moment Correlation Coefficient showed no correlation between the 2 sets of data. Paired t-test showed that there was a statistically significant difference between the near and distance response AC/A ratios (t?=?3.30, p?=?0.003). The difference was found to be greater in participants who were non-orthoptic students.

Conclusion: The response AC/A ratio was found to be slightly higher at 33?cm with plus lenses than at 3.8 m with minus lenses. No reason was identified for this difference but adaptation and perceptual effects could be further explored.     

A mathematical model of factors that influence the performance of accommodative intraocular lenses

In this work a mathematical model of capsule movement during pseudophakic accommodation is described to allow identification and evaluation of factors that may explain the variation in effect of accommodative intraocular lenses (IOLs) between patients. The model assumes that increasing vitreous pressure pushes the lens capsule forward as a circular diaphragm and that this movement is from a fixed fulcrum. With an IOL in situ, the capsule is taken to have a non-uniform thickness due to the presence of the anterior capsulorhexis. The model assumes a uniform capsular elasticity and ignores contributions from cellular elements such as posterior capsule opacification. Using our model and a regression formula to calculate capsular bag size, taking into account axial length and keratometry values, we are able to predict accommodative effect in individual patients. By simple geometry we have developed a mathematical model to identify variables that are important in pseudophakic accommodation. It provides the basis for the development of a more complex model that would address the movement of a lens taking into account the influence of the zonular system during accommodation.     

A Model for Predicting the Results of Orthoptics in Patients with Equal Exodeviations

ABSTRACT Stepwise discriminant and discriminant analysis of the data of a retrospective study of patients with equal (or basic) exodeviation has been completed. Based upon this calibration data, these analyses have allowed the formulation of a classification criterion for the success of orthoptic treatment. Included in the model were the following factors: the frequency of the deviation, the AC/A ratio, the angle of deviation at the nearpoint and the recovery value of the distance positive vergences. Patients with latent deviations, higher AC/A ratios, smaller near angles of deviation and smaller recovery values were more likely to be successful. The model in the form of a pair of linearised discriminant functions is presented. The possible relationship of the model to real-world processes, utility and limits are briefly discussed.     

The prevalence of vergence accommodation disorders in a school-age population

There is a substantial void in the literature of studies that examine the prevalence of non-strabismic binocular disorders in the population. Using contemporary vergence accommodation criteria this study set out to classify the binocular status of school-age patients presenting for initial examination in an optometric practice. Seventy-seven per cent of those presenting had a significant vergence or accommodation disorder on the basis of the stated criteria, and disorders at near made up 90 per cent of the disorders detected. Disorders of accommodation effected 57 per cent of the sample and vergence disorders 58 per cent. Analysis of presenting complaint was not of predictive value in determining whether an anomaly was present, nor was it helpful in predicting which type of anomaly. Hyperopia, astigmatism and anisometropia were however more likely to be associated with a vergence accommodation disorder. Distribution of fixation disparity (FDC) curve types for this clinical population is presented together with some evidence to suggest a distinct sub- group within Type 1 responses.     

Accommodative function in school children with reading difficulties

Background  Prior findings suggest correlation between reading problems and accommodative function, but few studies have assessed accommodation in children with poor reading skills. Our aim was to characterize monocular accommodative amplitude, relative accommodation and binocular accommodative facility in a population of healthy, non-dyslexic primary school children with reading difficulties. Methods  We conducted a cross-sectional study on 87 poor readers and 32 control children (all between 8 and 13 years of age) in grades three to six recruited from 11 elementary schools in Madrid, Spain. In each subject with best spectacle correction, negative relative accommodation (NRA) and positive relative accommodation (PRA) were measured using a phoropter, monocular accommodative amplitude (MAA) was determined using the minus lenses method, and binocular accommodative facility (BAF) was measured using the Bernell Acuity Suppression Slide (VO/9) and a ± 2.00 D accommodative demand for a period of 1 minute. Results  Monocular accommodative amplitude was significantly lower (p < 0.001) in the group of poor readers (right eye 9.1 D ± 2.3, left eye 9.0 D ± 2.3) than in the control group (right eye 10.5 D ± 1.7, left eye 10.5 D ± 1.7). Binocular accommodative facility values were significantly lower (p < 0.05) in the poor readers (4.9 cpm ± 3.1) than controls (6.3 cpm ± 2.9). Negative and positive relative accommodation values were similar in both groups of children. Conclusions  This study provides data on the accommodative capacity of a population of children with reading difficulties. Our findings suggest a reduced monocular accommodative amplitude and binocular accommodative facility, such that this function should be assessed by an optometric clinician in children whose reading level is below average. Human subjects and informed consent  The authors confirm that this research was performed followed the tenets of the Declaration of Helsinki, and that informed consent was obtained from the subjects after having explained to them in detail the nature of the study. The study protocol was approved by the Clinical Research Ethics Committee of the School of Optometry.     

调节滞后与儿童近视关系的研究

目的：观察并评价调节滞后与儿童近视关系,探讨儿童近视发病机理。方法：使用分光镜动态检影法测定３８名年龄６￣１４岁在学儿童（平均年龄１０．１岁）的张力性调节值与调节滞后值。其中１９名为正视,１９名为近视。通过注射昏暗照明不置于眼前４０厘米的ＤＯＧ视标（０．２ｃｐｄ）打开调节环,于持续聚焦于－３Ｄ目标５分钟之前及之后立即测定张力性调节值,取前后差值作为调节滞后值。统计分析采用组间样本ｔ检验方法。结果：     

Validity and repeatability of the modified push-up method for measuring the amplitude of accommodation

Introduction : The modified push-up method is recommended for testing the amplitude of accommodation in young children. In this study, the modified push-up method was compared with the conventional push-up method for measuring the amplitude of accommodation. Methods : Three experiments were carried out in the validity study. The first experiment was set up to compare the measured amplitudes between the modified push-up method and the conventional push-up method. The second and third experiments were carried out to further investigate the possible contribution of the target choice or criterion choice, respectively, to the measured amplitude results. The repeatability study was then performed. Results : The modified push-up method produced lower measures of the amplitude of accommodation than the conventional push-up method. The average difference was 0.40 D monocularly and 1.30 D binocularly. The choices of both target and criterion significantly contributed to the difference. The modified push-up method was a highly repeatable method. Conclusion : We conclude that the modified push-up method is interchangeable with the conventional push-up method for clinical use, but lower amplitude readings by 0.40 D monocularly and 1.3 D binocularly would be expected.     

Investigation of amplitude of accommodation among Ghanaian school children

Background: Deficient amplitude of accommodation is the most frequently used criteria in an optometric practice in diagnosing whether a patient has accommodative insufficiency. This deficiency is determined based on an age‐related expected finding calculated using Hofstetter's equation derived from Donder's and Duane's data. The aim of the present study was to investigate the amplitude of accommodation among Ghanaian school children and to compare the findings with age‐expected norms predicted by Hofstetter's equation. Methods: The amplitude of accommodation was measured using the push‐up method in a random sample of 435 school children from the Cape Coast Municipality. The mean amplitude of accommodation was compared with the age‐expected amplitude of accommodation as predicted by Hofstetter's equation for average amplitude of accommodation. Results: The mean amplitude of accommodation was 16.86 ± 3.07 D (95% CI = 16.57, 17.15). This is significantly higher than age‐expected norms calculated using Hofstetter's equation. The amplitude of accommodation showed the characteristic decline with age. Conclusion: From the results, we conclude that the age‐expected norms for amplitude of accommodation using Hofstetter's equation might not be accurate for Ghanaian children.     

MEM and Nott dynamic retinoscopy in patients with disorders of vergence and accommodation

The accommodative response in 34 patients with accommodative and binocular disorders was assessed with two different techniques of dynamic retinoscopy used in clinical practice: monocular estimate method (MEM) and Nott retinoscopy. The data obtained by both techniques were compared, evaluating the correlation and agreement between them. Results showed that there were statistically significant differences between the techniques with MEM values being more plus than Nott ones. There was a high correlation between the two techniques (0.90) and the regression analysis indicated that a linear relationship existed between MEM and Nott dynamic retinoscopy, so that accommodative lag value for Nott dynamic retinoscopy would be calculated by dividing the MEM result by 2. However, although both retinoscopies were related, there was a lack of agreement between them (+/-0.53 D) indicating that the two methods are not interchangeable for clinical purposes.     

近视青少年配戴角膜塑形镜前后调节参数变化

目的：:观察近视青少年配戴角膜塑形镜前后调节参数及隐斜度的变化,探讨角膜塑形镜延缓近视进展的机制及近视发病病因。方法：:回顾性研究。收集2011年1月至2019年3月在中国医科大学附属第一医院眼科门诊进行角膜塑形镜配戴前后调节参数资料完整的患者51例（102眼）,比较角膜塑形镜配戴前、配戴后1、12个月或以上的正负相对...     

Accommodation and the relationship to subjective symptoms with near work for young school children

The aim of this work was to study the relation between subjective symptoms at near and ocular accommodation in terms of the amplitude of accommodation and the relative accommodation. A secondary aim was to discuss the diagnosis of accommodative insufficiency. The chosen cohort was examined on two occasions with 1.8 years in between. The first examination included 72 children, 43 boys (mean age 8.1 years, ranging from 5.8 to 9.8) and 29 girls (mean age 8.3 years, ranging from 6.2 to 10.0). The second examination included 59 of these children, 34 boys (mean age 9.9 years, ranging from 7.8 to 11.7) and 25 girls (mean age 10.1 ranging from 8.0 to 11.8). Subjective symptoms at near work (headache, asthenopia, floating text, facility problems) were recorded and the amplitude and the relative accommodation, both positive and negative, were measured. The result from the questionnaire showed that at the first examination more than one‐third of the children (34.7%) reported at least one subjective symptom when doing near work and 42.4% at the second examination. No symptoms were found among children younger than 7.5 years, but for children between 7.5 and 10 years old at the first examination, the prevalence of at least one symptom was 47.2%. At the second examination, symptoms were reported also for the youngest children, i.e. from the age of 8 years. The discrimination ability for the amplitude of accommodation, both monocular and binocular, was significant. In the first examination the difference between the mean for the two groups (i.e. with and without at least one symptom) was around 2.00 D monocular and 3.00 D binocular. Corresponding figures from the second examination was a difference between the mean for the two groups of around 3.50 D monocular and nearly 4.00 D binocular. We suggest that accommodation measurements should be performed more routinely and regularly, maybe as screening, especially in children over 8 years of age.