学龄期近视进展儿童调节功能的客观检查和分析

目的　对学龄期近视进展儿童进行调节功能的客观检查与分析，观察调节功能与近视进展之间的相关性。方法　选取2017年至2018年在首都医科大学附属北京同仁医院视光学门诊定期就诊的71名学龄期儿童为研究对象，根据受试者近年的屈光度进展速度，按≤0.50 D·a^-1、>0.50~1.00 D·a^-1、>1.00~1.50 D·a^-1、>1.50 D·a^-1分为4组，使用人眼调节分析仪对受试者进行调节功能的客观测量与分析，记录不同调节刺激视标下4组的客观调节反应值和客观调节微波动值，并作对比。结果　在所有调节视标上，各组随着调节刺激幅度增加，客观调节反应值也逐渐增加，4组在不同调节刺激视标下的客观调节反应值及平均的客观调节反应值差异均无统计学意义（均为P＞0.05）。≤0.50 D·a^-1、>0.50~1.00 D·a^-1、>1.00~1.50 D·a^-1、>1.50 D·a^-1近视进展速度组调节微波动值分别为（62.2±5.6）D、（62.5±5.3）D、（66.5±6.0）D和（58.0±6.5）D，4组间差异有统计学意义（F=6.424，P=0.001），在+0.50~-0.50 D、-2.00 D调节刺激视标下，4组的客观调节微波动值比较差异均有统计学意义（均为P＜0.05），在其余调节刺激视标下差异均无统计学意义（均为P＞0.05）。结论　对于学龄期儿童的近视进展速度，客观调节微波动值相对于客观调节反应值可能是一个更为敏感的相关指标。     

Accommodative hysteresis under static and dynamic stimulus conditions

The influence of continuous variation in dioptric demand on the accommodative hysteresis induced at near distances was examined in 14 visually-normal young adults. Tonic accommodation was measured before and after 10 minutes of sustained focus using a constant stimulus at 5 D, 6.5 D, and 8 D, as well as a stimulus which slowly and alternately increased and decreased over the continuous range from 5 D to 8 D. For approximately half the subjects, dioptric demand had to be very high (8 D) under static conditions to produce moderate but significant hysteresis, yet little or no attenuation of the effect occurred under the dynamic condition. For other subjects who consistently showed very large tonic changes (1.4 D or more) under static conditions, the hysteresis effect generated under dynamic conditions was greatly reduced (approximately 50 per cent) in magnitude. These findings suggest that the degree to which continuous variation in dioptric demand will disrupt the adaptive process may depend on individual differences in the rate and/or maximum level of tonic accommodative change. Such a relationship could have bearing on the particular strategy recommended for individuals who tend to experience blur at distance following nearwork.     

Cardinal points and image–object magnification with an accommodative lens implant (1 CU)

A simple mathematical method for the determination of the cardinal points of pseudophakic eyes after implantation of an accommodative intraocular lens [posterior chamber intraocular lenses (PCIOL)] is presented. The purpose of this study was to explore the changes during pseudophakic accommodation (PAC) in (1). the positions of the cardinal points, (2). the distance of the object conjugate with the retina, and (3). the image-object magnification. These theoretical accommodation data are compared with clinical measurements. METHODS AND PATIENTS: Using biometrical measurements of the axial length, equivalent power of the cornea and the anterior chamber depth (ACD) in the non-accommodated state we used linear geometric optics for determination of the cardinal points and object distance as well as lateral magnification (the ratio of image to object size). With the measurement of ACD decrease (following pharmacological stimulation of the ciliary muscle with 2% pilocarpine eye drops) we determined the changes of the cardinal points and magnification to assess PAC amplitude from the shortening of the object distance. Calculated values of PAC amplitude were compared with the respective measured values derived from amplitude measures by accommodometer, defocusing and streak retinoscopy. We analysed the results of a prospective study on 35 eyes of 28 patients after cataract surgery (target refraction: -0.2 D) and accommodative PCIOL implantation (1 CU, Human Optics AG, Erlangen, Germany) 3 months after surgery. RESULTS: After pilocarpine eye drops, ACD (mean +/- S.D., range; median) decreased by 0.88 +/- 0.48 mm (0.51-1.91; 0.66). Distance of the in-focus object decreased from the non-accommodated state (-5.62 +/- 1.83 m, -25 to -1.1; -4.83 m) to the accommodated state (ACD decrease) (-0.81 +/- 0.21, -2.11 to -0.65; -0.79 m). For a theoretical ACD decrease of 1.0 mm (the intrinsic limitation of the PCIOL design) it was -0.59 +/- 0.28, -1.31 to -0.51; -0.63 m and resulted in an objective accommodative response of 1.49 +/- 0.16, 1.21-1.81; 1.46 D, depending on the actual geometry of the individual eye. On average, magnification as induced by PAC in contrast to that induced by adequate spectacle addition differed by only about 1%. Accommodation measured with defocusing and the accommodometer correlated significantly with the theoretical value based on IOLMaster measurement of ACD decrease (r = 0.752, p = 0.005 and r = 0.676, p = 0.02). Likewise, accommodation measured with streak retinoscopy correlated weakly with the theoretical value based on IOLMaster ACD decrease (r = 0.465, p = 0.05). CONCLUSIONS: Using geometrical optics, PAC can be derived from the biometric data of the eye and the measured ACD decrease. This approach may be an additional indicator for the accommodative response in pseudophakic patients and may allow a subdivision of the measured accommodation into true PAC and pseudoaccommodation, for example, because of increased depth of focus induced by pupillary constriction.     

Evolution of accommodative function and development of ocular movements in children

The evolution of the accommodative function and development of ocular movement are evaluated in a non-clinical paediatric population (1056 subjects) aged 6-12 years, providing means for each age in the optometric tests that evaluate the accommodative amplitude, accommodative facility, accommodative response (lag), and saccadic movements. A comparison of these values between ages (anova) established three distinct trends in the behaviour of these parameters. The accommodative amplitude, measured by modified dynamic retinoscopy, and the evaluation of the saccadic movements by the development of ocular movements [developmental eye movement (DEM)] test showed continuous change with age. The values for monocular and binocular accommodative facility, measured by +/-2.00 D flippers, indicated the need to divide the population into two age groups (6-7 and 8-12 years). Finally, the means of accommodative response, measured by monocular estimation model (MEM) retinoscopy, and the direct observation of saccadic movement revealed no significant differences between ages, establishing a single mean reference value for the age group studied.     

Pseudophakic accommodation with translation lenses – dual optic vs mono optic

PURPOSE: To investigate the pseudophakic accommodation effect in dual and mono optic translation accommodative intraocular lenses (AIOL) using linear matrix methods in the paraxial space. METHODS: Dual (anterior optic of power +32 D linked to a compensatory posterior optic of negative power) and mono lens power was determined in the non-accommodated state using linear geometric optics based on the Gullstrand model eye. The position of the AIOL was calculated from a regression formula. Pseudophakic accommodation was assessed with three systems: (1) forward shift of the mono optic lens, (2) anterior translation of the anterior optic in the dual optic lens system with an unchanged position of the posterior minus lens and (3) symmetrical anterior and posterior translation of the anterior and posterior lens. The Gullstrand model eye was modified by changing the axial length (and proportionally changing the phakic anterior chamber depth) to investigate the accommodative effect in myopic and hyperopic eyes. RESULTS: The dual optic lens system (2) yields a nearly constant accommodation amplitude of 2.4-2.5 D mm(-1) movement over the total range of axial lengths. The mono optic lens (1) provides a higher accommodative effect only in extremely short eyes (high refractive power of the lens), whereas for normal eyes (1.4-1.5 D mm(-1) movement) and for long (myopic) eyes the accommodative effect is much less than the dual optic lens. The dual optic lens system under condition (3) yields less accommodation amplitude compared with the dual optic system under condition (2) over the total range of axial length but provides higher accommodation amplitude compared with the mono optic lens system (1) with axial lengths greater than 22.3 mm (lens power 25.5 D). In the accommodated state, with lens translation of 1 mm, the absolute value of the lateral magnification increases with the refractive power of the mono optic lens (1) and decreases in both dual optic lens systems (under conditions 2 and 3). CONCLUSIONS: A mathematical strategy is presented for calculation of the accommodative effect of mono-optic and dual optic AIOL. The dual optic lens yielded a nearly constant accommodation amplitude of about 2.4-2.5 D mm(-1) translation, whereas the mono optic lens yielded an accommodative response of <2 D mm(-1) translation in long myopic or normal eyes. Only in extremely short eyes is the accommodative amplitude of the mono-optic lens higher than the dual optic lens.     

Spectacle use and reduced unaided vision in third grade students: a comparative study in different educational settings

Background: The development of myopia is influenced by hereditary factors, environmental factors and geneenvironment interaction. Reading and near‐work activity are associated with myopia and myopic progression. This study sought to determine and compare the prevalence of reduced unaided vision and spectacle use among third grade Israeli students from three different educational settings. Method: A sample of 917 students (mean age 8.5 years, range seven to 10 years) was drawn from the three Israeli educational streams: secular, Orthodox and ultra‐Orthodox. Children in the ultra‐Orthodox education pathway begin studying at the age of three years and their daily reading involves sustained near work with increased accommodative effort accompanied by head‐rocking movements. Reduced distance vision was used to indicate the likely development of or an increase in the amount of myopia. Spectacle lenses were measured to determine the prevalence of myopia. Results: Of the 917 students studied, 103 (11.2 per cent) wore spectacles (14.2 per cent of the males and eight per cent of the females); 82.5 per cent of those who wore spectacles were myopic. Males from ultra‐Orthodox schools had the highest rate of reduced unaided vision (72.5 per cent) compared with males from secular schools (27.3 per cent), males from Orthodox schools (59.3 per cent) or with females from all three groups (average of 34.8 per cent, p < 0.0001, chi squared). Males had a higher rate of reduced unaided vision, especially in the Orthodox and ultra‐Orthodox schools. Conclusions: Our study suggests that Jewish ultra‐Orthodox males have a higher prevalence and degree of myopia. The study habits of young children, including exposure to prolonged near tasks, high accommodative demands and possibly optical defocus induced by body sway, may contribute to the development of myopia.     

Comparison of Visual Function after Multifocal and Accommodative IOL Implantation

Purpose： To compare early visual function between patients undergoing phacoemulsification combined with multifocal and accommodative intraocular lens implantation.
Methods： A total of 112 patients with age-related cataract undergoing phacoemulsification in our hospital were recruited for this study and randomly assigned into multifocal （56 eyes; ZAM00 group） and accommodative （56 eyes; FLEX group） intraocular lens groups. Visual acuity and contrast sensitivity were statistically compared between the two groups.
Results： No significant difference was found in uncorrected distant visual acuity between the ZMA00 and FLEX groups at 1 week, or 1, 3, and 6 months after operation （all P〉0.05）. At postoperative 6 months, no statistical significance was noted in distant and intermediate best-corrected visual acuity or in contrast sensitivity between the two groups （all P〉0.05）. Patients in the ZMA00 group were superior to their counterparts in the FLEX group regarding near best corrected visual acuity, reading speed, and spectacle independence （all P〈0.05）.
Conclusion： ZMA00 and FLEX IOL implantation can provide excellent distant and intermediate visual acuity for patients with age-related cataract. ZMA00 IOL is superior to FLEX in terms of near visual acuity.     

Appraisal and coping with daily stressors by pediatric patients with chronic abdominal pain

OBJECTIVE: To test the hypothesis that pain patients differ from well children in their appraisal and coping with daily stressors and to test a model of the relation of stress appraisal and coping to symptoms and disability. METHODS: Pediatric patients with chronic abdominal pain (n = 143) and well children (n = 104) completed a 5-day diary study regarding their appraisal and coping with daily stressors. Somatic symptoms, depressive symptoms, and functional disability were assessed 2 months later. RESULTS: Compared to well children, pain patients were less confident of their ability either to change or to adapt to stress and were less likely to use accommodative coping strategies. Different patterns of stress appraisal were associated with active, passive, and accommodative coping. Both appraisals and coping were significantly related to symptoms and disability. CONCLUSIONS: The relation between stress and symptoms in pediatric pain patients may be explained in part by their appraisal and coping with stressors. The relation between appraisal and coping was consistent with Lazarus, R. S., & Folkman, S. (1984). Stress, Appraisal, and Coping. New York: Springer.     

中心性浆液性脉络膜视网膜病变患眼的调节功能

目的研究中心性浆液性脉络膜视网膜病变(central serous chorioretinopathy,CSC)患眼与健眼的调节功能及其影响因素。方法分别对31例原先为正视眼的单眼活动期CSC患眼及健眼进行调节幅度、调节灵活度、调节滞后量的测定。结果在调节幅度的检测中,患眼组的调节幅度值平均为(4.89±1.28)D,健眼组的调节幅度值平均为(6.58±1.53)D,两者相比较差异有显著性(P<0.01);调节灵活度测量结果显示患眼组比健眼组明显要慢,患眼组的调节灵活度为(3.16±2.36)cpm,健眼组的调节灵活度为(5.84±2.41)cpm,两组相比较差异有显著性(P<0.01);在调节滞后的测量中,患眼组大多集中在0.75～1.25D之间,健眼组大多在0.50～0.75D之间,患眼组的调节反应明显滞后于健眼组,两组相比较差异有显著性(P<0.01)。结论CSC患眼的调节功能低于健眼的调节功能。     

儿童部分调节性内斜视的手术探讨

目的探讨儿童部分调节性内斜视的手术时机，手术量。方法对35例部分词节性内斜视的患儿戴全矫眼镜半年以后，手术矫治与调节因素无关的非调节因素所致的内斜视。手术量按裸眼和戴镜后斜视度的平均值设计。结果35例中．眼位矫正满意32例占91．43％，良好3例占8．57％；功能治愈有立体视19例占54．29％。结论儿童部分调节性内斜视，其由解剖因素所致的斜视需手术矫正。当患儿戴全矫眼镜半年眼位仍不能恢复正位时，可尽早手术矫治其残存的内斜度，手术量按裸眼与戴镜平均斜视度设计，术后由于调节因素所致内斜仍需配镜矫正。