准分子激光治疗近视眼

本文对准分子激光PRK治疗近视眼息者503例的早期临床结果进行分析,近视范围为－2．0至－15．0D,根据术前屈光度不同分为三组,术后随访三个月．结果证实准分子激光是一种安全、有效、预测性较好的治疗近视眼方法．全部病人提高了裸眼视力,绝大部分保持了最佳矫正视力,且没有产生危及视力的并发症．     

BMI and retinal vascular caliber in children

Objective: In adult populations, changes in retinal vascular caliber have been linked with obesity and metabolic syndrome. We examined the association of BMI and weight with retinal vascular caliber in children. Research Methods and Procedures: This was a school‐based, cross‐sectional study of 768 children, 7 to 9 years old, randomly sampled from the Singapore Cohort Study of the Risk Factors for Myopia. Participants had digital retinal photographs. Retinal vascular caliber was measured using a computer‐based program and combined to provide average calibers of arterioles and venules in that eye. Weight and height were measured using standardized protocol. These data were used to calculate BMI. Results: In this population, the mean retinal arteriolar and venular calibers were 156.40 μm [95% confidence interval (CI), 155.44 to 157.36] and 225.43 μm (95% CI, 224.10 to 226.74) respectively. After controlling for age, gender, race, parental monthly income, axial length, birth weight, and birth length, each 3.1 kg/m² (standard deviation) increase in BMI was associated with a 2.55‐μm (95% CI, 1.21 to 3.89; p < 0.001) larger retinal venular caliber. In multivariable analysis, greater weight was also significantly associated with larger retinal venular caliber. BMI and weight were not associated with retinal arteriolar caliber. Height was not significantly associated with retinal arteriolar or venular caliber. Discussion: Greater BMI and weight are associated with larger retinal venular caliber in healthy children.     

光学相干断层成像术在近视眼视网膜神经纤维层厚度测量中的临床应用

目的:研究光学相干断层成像术(OCT)在近视眼视网膜神经纤维层(RNFL)厚度测量中的应用价值。方法:选择2016年1月到2016年5月在医院就诊的近视患者73例(138眼)纳入此次研究,根据近视情况将患者分为低度近视组(-0.30D~-3.00D)共26例(48眼)、中度近视组(-3.01~-6.00D)共24例(47眼)及高度近视组(-6.00D)共23例(43眼)。另选同期在医院体检(视力正常)的健康志愿者25例(45眼)作为对照组,对比各组不同象限的RNFL厚度,屈光度及眼轴长度,分析近视眼各象限的RNFL厚度与患者屈光度和眼轴长度的相关性。结果:高度近视组的上方象限、下方象限以及鼻侧象限的RNFL厚度均明显低于对照组及中度近视组,中度近视组的下方象限及鼻侧象限的RNFL厚度均明显低于对照组,低度近视组鼻侧象限的RNFL厚度明显低于对照组,差异均有统计学意义(均P0.05)。近视组的屈光度及眼轴长度均明显大于对照组,且高度近视组均明显大于中度近视组与低度近视组,中度近视组均明显大于低度近视组,差异均有统计学意义(均P0.05)。根据Pearson法分析相关性可知,近视眼患者上象限、下象限、鼻侧象限的RNFL厚度与其屈光度及眼轴长度均呈负相关。结论:利用OCT技术检测近视眼RNFL厚度时,应考虑屈光度及眼轴长度可能造成的影响,综合进行分析判断,以获得最佳检测数值。     

近视眼激光角膜切除术原理及控制方法

本文从理论上研究了激光人眼角膜切除术的原理和控制方法。详细分析了角膜前表面的曲率半径对近发消融深度和治疗结果的影响。     

The refractive development of the eye of the American kestrel (Falco sparverius): a new avian model

Summary Most measures of avian visual performance are carried out on commonly available domestic species such as the chicken, and most of the data on avian induced refractive error deals with chickens. Raptors are predatory birds in which good visual resolving ability is particularly important. Behavioral studies indicate that the eyes of raptors have two to three times the resolving ability of the human eye. The domestic chicken is precocial at hatching whereas most raptors are semi-altricial. This study was an effort to determine if the effect of early visual deprivation on the refractive development of the chicken eye can be reproduced in the American kestrel, a species which is not domesticated and in which the need for acute vision is particularly important.Visual deprivation was achieved by unilaterally applying translucent plastic goggles over the eyes of kestrels two days after hatching. Refractive error was measured using a retinoscope and trial lenses. Ocular growth was monitored by A-scan ultrasonography, and frozen ocular sections of sacrificed birds. The effect of the experimental manipulation on the contralateral control eye and body weight was evaluated each day over a 42-day period. The goggles did not significantly affect the normal changes in body weight or the normal pattern of ocular growth and refractive development in the untreated eyes. An analysis of the refractive state changes as a result of form deprivation was made each week for 6 weeks after hatching on both the treated and untreated eyes in a separate group of experimental birds. Visual form deprivation caused a significant myopic shift in refractive error and a significant increase in the vitreous chamber depth in the treated eyes at 3 and 6 weeks of age. However, the amount of myopia produced is much less than that induced in chicks, and in certain cases hyperopia is produced. The kestrels recover from myopia and hyperopia within 10 days of goggle removal, after 3 to 4 weeks of deprivation.This study is the first indication that chickens may not be a representative bird model for studying form deprivation myopia. First, myopia is not always produced in kestrels in response to form deprivation. Second, kestrels are severely myopic at hatching and therefore, the direction of emmetropization is opposite to that found in hatchling chicks.     

Heritability and shared environment estimates for myopia and associated ocular biometric traits: the Genes in Myopia (GEM) family study

To examine the familial correlations, heritability (h ²) and common environmental components (c ²) of myopia and ocular biometric traits (all treated as continuous outcomes) in families collected through the Genes in Myopia (GEM) family study in Australia. A total of 132 pedigrees (723 participants) were recruited for this study. All individuals completed a risk factor questionnaire and underwent a detailed eye examination including spherical equivalent (SphE) and ocular biometric measurements of axial length (AL), anterior chamber depth (ACD) and corneal curvature (CC). Familial correlations were calculated and h ² and c² were estimated using a variance component model that assumes a multivariate t distribution within each pedigree. Two definitions of common environments (c ²) were considered: nuclear family (current) shared environment (Model 1) and sib-ship (childhood) shared environment (Model 2). Population ascertainment adjustment was performed using the Blue Mountains eye study dataset. The trends observed for familial correlations suggested that SphE is influenced by both environmental and genetic factors whereas AL, ACD and CC are predominantly genetically determined. This was largely confirmed by variance components modelling. Heritability estimates (adjusted for age, sex and years of education) from the best fitting ACE model (Model 2, childhood shared environment) were 0.50 ± 0.05 for SphE, 0.73 ± 0.04 for AL, 0.78 ± 0.04 for ACD and 0.16 ± 0.06 for CC. Childhood environmental effects were significant with c ² estimated to be 0.33 ± 0.04 for SphE, 0.06 ± 0.03 for AL, 0.22 ± 0.04 for ACD and 0.10 ± 0.05 for CC. Age was associated with SphE, total years of education was associated with AL and sex was associated with all traits studied. We used a novel and conservative approach to account for and estimate common environmental effects by specifying either nuclear family or sib-ship environment when estimating heritability estimates and showed that all traits examined (SphE, AL, ACD and CC) are heritable, thus reflecting a genetic component. These traits therefore all represent candidates for quantitative trait linkage analyses.     

MMP-2与Ⅰ型胶原关系的研究进展

MMP-2与I型胶原分别为基质金属蛋白酶家族的重要成员和细胞外基质的主要成分,近年来研究发现,MMP-2与Ⅰ型胶原的表达与调控在多种与胶原代谢有关的疾病中起着重要作用。通过增强或抑制MMP-2来调控I型胶原,进而防止疾病的发生发展已成为很多疾病的研究热点。对MMP-2与Ⅰ型胶原关系更新的认识也引起了越来越多的关注,必然带动对MMP-2与Ⅰ型胶原更深层次的研究,本文就近年来有关MMP-2与Ⅰ型胶原的研究进展做一综述,为多种胶原代谢疾病发病机理与防治的探究提供新的思路和理论依据。     

准分子激光表层无痕术治疗近视患者的临床疗效分析

目的:研究准分子激光表层无痕术治疗近视患者的临床疗效。方法:选择2014年6月~2015年11月在我院进行准分子激光表层无痕术治疗的近视患者110例(198眼),根据眼屈光度数分为低(-1.00~-3.00 D)、中(-3~-6 D)、高(≥-6 D)度近视组。应用准分子激光对上皮层、前弹力层和前部基质层采取屈光性的切削,使眼球的表面稍微变平,角膜曲率进而改变。于术后复查眼部症状、上皮愈合情况、裸眼视力、矫正视力和屈光度。结果:仅少数患者于术后有不同程度的异物感,182眼(91.92%)角膜上皮在3天内愈合;术后所有患者的眼部均出现了不同程度的疼痛,但随着时间的增长逐渐好转,术后6 d疼痛感消失;与术前裸眼视力相比,三组在术后1天、1周、2周、1月和3月视力均明显升高,差异有统计学意义(P0.05);高度近视组在术后各时期的视力均明显低于低度近视组(P0.05);随着术后时间的延长,三组术后不同时间残余屈光度≤±1.00 D的百分比均有不同程度的升高,差异无统计学意义(P0.05);高度近视组在术后不同时间残余屈光度≤±1.00 D的百分比均明显低于低度近视组(P0.05);所有患者均无严重并发症发生,在随访期间无一例发生高眼压。结论:准分子激光表层无痕术能做到角膜无创口,有较高的预测性、安全性及有效性,且术后并发症少,有较好的应用前景。