Air pollution and COPD in China

Recently, many researchers paid more attentions to the association between air pollution and chronic obstructive pulmonary disease (COPD). Haze, a severe form of outdoor air pollution, affected most parts of northern and eastern China in the past winter. In China, studies have been performed to evaluate the impact of outdoor air pollution and biomass smoke exposure on COPD; and most studies have focused on the role of air pollution in acutely triggering symptoms and exacerbations. Few studies have examined the role of air pollution in inducing pathophysiological changes that characterise COPD. Evidence showed that outdoor air pollution affects lung function in both children and adults and triggers exacerbations of COPD symptoms. Hence outdoor air pollution may be considered a risk factor for COPD mortality. However, evidence to date has been suggestive (not conclusive) that chronic exposure to outdoor air pollution increases the prevalence and incidence of COPD. Cross-sectional studies showed biomass smoke exposure is a risk factor for COPD. A long-term retrospective study and a long-term prospective cohort study showed that biomass smoke exposure reductions were associated with a reduced decline in forced expiratory volume in 1 second (FEV₁) and with a decreased risk of COPD. To fully understand the effect of air pollution on COPD, we recommend future studies with longer follow-up periods, more standardized definitions of COPD and more refined and source-specific exposure assessments.     

济宁市市区居民PM2.5相关知识知晓情况调查

目的分析济宁市居民对PM2.5相关知识知晓情况,为政府以及相关部门制定科学合理的政策及措施提供科学依据。方法 2013年4月对400名调查对象进行问卷调查。调查居民对PM2.5的主要来源、化学成分、健康危害等的认知情况,对空气质量的关注程度,济宁雾霾天气的好发季节,在雾霾天气时所采取的防护措施以及对如何有效减少雾霾天气的建议和意见。根据数据类型采用统计描述、t检验、单因素方差分析等统计学方法,P0.05为差异有统计学意义。结果发放问卷400份,实际收回369份,有效问卷369份,回收率为92.3%。被调查的369名居民中,关于PM2.5主要来源完全了解的70名,占19.0%;非常了解的107名,占29.0%;一般了解的163名,占44.2%;完全不了解的29名,占7.8%。关于化学成分完全了解的12名,占3.3%;非常了解的42名,占11.4%;一般了解的256名,占69.4%;完全不了解的59名,占15.9%。对PM2.5的健康危害认知平均得分(3.01±1.87)分。不同性别的居民对PM2.5健康危害认知得分差异无统计学意义(P0.05),不同年龄、文化程度、职业的居民对PM2.5健康危害认知的得分差异均有统计学意义(F=2.332、3.906、3.409,均P0.05)。被调查的369名居民中在雾霾天气时绝大多数人都采取了相应的防护措施,未采取任何防护措施仅42名,占11.4%。结论政府和相关部门有必要加强雾霾天气危害的宣传力度和采取相关措施,引起社会各方重视,提高居民在雾霾天气时的防护意识。     

高度近视行Trans-PRK术中联合MMC对术后haze的影响

目的：评价经上皮准分子激光角膜切削术(Trans-PRK)联合0.02%丝裂霉素C(MMC)治疗高度近视预防角膜上皮下雾状混浊(haze)的临床效果。

方法：回顾性病例分析。收集我院2016-01/2017-12行Trans-PRK手术治疗的高度近视患者89例142眼,其中94眼联合使用0.02% MMC设为MMC组,MMC的使用时间为30～45s; 48眼未使用MMC设为对照组。两组患者术后均规律使用类固醇激素滴眼液治疗4mo,随访6mo。采用树模型分析探讨不同相关因素与haze发生的相关性。

结果：按照Fantes分级进行haze评估。MMC组术后haze发生率为8.5%(8/94),对照组为33.3%(16/48)(P=0.001)。树模型结果显示,切削光区直径和切削深度是haze发生的主要相关因素(P<0.01)。当切削光区直径≤5.6mm时发生haze的可能性越大,当切削光区直径>5.6mm时,最大切削深度成为haze发生的主要影响因素。

结论：对于薄角膜及角膜形态异常的高度近视患者,在选择Trans-PRK治疗时应考虑切削光区直径及切削深度,同时应联合使用0.02% MMC,可以安全有效地减少haze发生。     

Pollutional haze as a potential cause of lung cancer

Along with fast economic growth over the past few decades, the world is faced with cumulatively serious environmental pollution and now is paying increased attention to pollutional haze. In the last few years, multiple epidemiological studies and animal models have provided compelling evidences that inhalation of pollutional haze could be linked to several adverse health effects. Since the respiratory tract is the crucial passageway of entry of pollutional haze, the lung is the main affected organ. Therefore, here, we reviewed some of the important information around long-term exposure to pollutional haze and lung cancer, as well as highlight important roles of pollutional haze in human lung carcinogenesis, providing evidence for pollutional haze acting as another risk factor for lung cancer.     

Effect of corneal light scatter on vision: a review of the literature

The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it.     

PRK术后角膜上皮下雾状混浊的相关因素分析

为探讨准分子激光角膜切削术（ｐｈｏｔｏｒｅｆｒａｃｔｉｖｅｋｅｒａｔｅｃｔｏｍｙ，ＰＲＫ）后角膜上皮下雾状混浊（ｈａｚｅ）的原因及影响因素，对ＰＲＫ后６个月时屈光度在－１．００～－１８．５０Ｄ的３１６例（６１５只眼）近视眼的ｈａｚｅ相关因素进行观察和比较。结果：ＰＲＫ后６个月时ｈａｚｅ发生率为４４．７％，１级或以上ｈａｚｅ为１３．３％。ｈａｚｅ的发生率及密度随屈光度增高而增加（Ｐ＜０．０００１），也随切削深度的增加而增加（Ｐ＜０．０００１），术前非接触眼压超过１８ｍｍＨｇ者，ｈａｚｅ的发生率和密度增加（Ｐ＜０．００５），男性较易发生ｈａｚｅ（Ｐ＝０．０００１），与年龄呈负相关（Ｐ＜０．０５）。而角膜厚度、术前戴用接触镜及散光对ｈａｚｅ的影响不显著。结论：高度近视（＞－６．０Ｄ）和过深的切削（＞８０μｍ）是引起ｈａｚｅ的主要原因。术前眼压偏高、年龄偏低对ｈａｚｅ也有明显影响。对ＰＲＫ治疗高度近视应持审     

丝裂霉素C辅助PRK的临床观察及并发症分析

目的： 观察丝裂霉素C(mitomycin C, MMC)辅助准分子激光角膜切削术(PRK)的疗效及并发症分析。

方法：回顾性临床病例研究。随机选择2009年40例80眼实施PRK治疗近视的患者作为常规组,2010年PRK术中应用0.2g/L MMC 20s的40例80眼作为MMC组。术后7d; 1,3,6,12mo观察裸眼视力、屈光状态以及角膜上皮愈合、发生糜烂、角膜干燥和haze情况,两组数据进行对比分析。

结果：术后12mo随访期间,两组裸眼视力、术后等效球镜、角膜上皮愈合及干眼情况差异无统计学意义。常规组有2眼,MMC组有9眼发生角膜糜烂伴丝状角膜炎,两组差异有统计学意义(Pearson χ²=4.783,P<0.05)。全部病例均治愈,没有复发病例。常规组、MMC组术后1,3,6,12mo haze的发生率分别为26%,6%,2%,0和44%,25%,10%,2%,术后1mo(Pearson χ²=5.385,P<0.05)、3mo(Pearson χ²=10.667,P=0.001)差异有统计学意义。

结论：PRK术中使用0.2g/L MMC可以减少术后haze的发生。MMC对PRK术中保留的角膜上皮的影响可能是术后角膜糜烂发生的原因之一,术中要避免接触到治疗区外保留的正常角膜上皮。     

Long-term effects of glaucoma therapy with 4% pilocarpine gel on corneal clarity and endothelial cell density

Corneal thickness measurements and endothelial cell counts were carried out in 34 patients undergoing treatment for glaucoma with 4% pilocarpine gel between 18 to 78 months after initiation of therapy. The corneal thickness and endothelial cell population were found to be within normal limits in all cases except two, one patient with increased corneal thickness who had recently undergone cataract and glaucoma filtering surgery and another patient with decreased cell count who had an old endothelial scar sustained prior to pilocarpine gel therapy. There was a very close correlation for both of these parameters noticed in patients treated with pilocarpine gel and in age-matched control group of patients with glaucoma. The present study has shown that there are no adverse corneal effects with pilocarpine gel therapy.     

Corneal response to femtosecond laser photodisruption in the rabbit

In this report we evaluated the effect of femtosecond laser energy on the development of corneal haze and keratocyte activation in rabbits following intra-stromal photodisruption to create LASIK flaps using a modified commercial femtosecond surgical laser. Three groups of flap parameters were studied: 1.5 microJ/pulse with 10 microm spot separation and complete side cut (Group 1); 3.5 microJ/pulse with 14 microm spot separation and complete side cut (Group 2); 3.5 microJ/pulse with 14 microm spot separation and partial (50 microm) side cut (Group 3). All flaps were left attached without lifting to avoid epithelial contamination. Rabbits were then evaluated pre- and post-operatively by quantitative in vivo and ex vivo confocal microscopy. The achieved flap thickness 1 week after surgery averaged 88.9+/-12.8, 90.8+/-6.9 and 86.5+/-6.8 microm for Groups 1-3 respectively (p=NS). Interface thickness was significantly greater (p<0.05) in the higher energy groups averaging 40.0+/-11.2 and 37.7+/-5.7 microm for Groups 2-3 compared to 28.6+/-4.5 microm for Group 1. Corneal haze was barely detectible and not significantly different between groups, although haze was detected in the region of the side-cuts in Groups 1 and 2. No clinically significant changes in stromal or epithelial thickness were noted. Laser confocal microscopy showed the presence of small diameter cells within the flap interface that resided within disrupted regions of the corneal collagen lamellae. Keratocyte activation was only detected in regions of the 100% side cut and not over the flap interface. In conclusion, the results of this study indicate that photodisruption of the corneal stroma alone without flap elevation regardless of laser energy does not induce significant corneal haze in the rabbit. However, a thicker stromal interface was seen with the higher energy suggesting greater stromal damage.     

准分子激光角膜切削术治疗高度、超高度近视眼术后角膜上皮下混浊的远期观察

目的:探讨准分子激光角膜切削术(PRK)治疗高度、超高度近视眼术后角膜上皮下雾状混浊(Haze)的发生情况及影响因素。方法:应用日本NIDEKEC-5000型准分子激光仪治疗高度、超高度近视眼143例(245眼),I组:-6.25～-10.00D,167眼;Ⅱ组-10.25～-24.00D,78眼。观察术后不同时期Haze的发生情况,随访7a以上。结果:术后3mo,0.5,1,4,7a,Haze的发生率,I组分别为74.8%,44.3%,24.5%,11.9%,7.8%;Ⅱ组为80.7%,52.1%,33.3%,24.3%,19.2%。7a时I组屈光度-0.57±1.84D,Ⅱ组-5.02±4.26D。有3级Haze7眼,I组2眼,为RK术后者;Ⅱ组5眼,4眼为年龄>40岁者。≥3级Haze者多出现在Ⅱ组,3～6mo达到高峰,持续时间达1a以上。结论:Haze为高度、超高度近视眼PRK术后的主要并发症。预矫屈光度越高,切削越深,则混浊程度越重;部分患者Haze逐渐减轻,角膜组织创伤修复时间长,部分重度Haze日后可能成为永久性瘢痕。