透气性硬性接触镜和框架眼镜矫正中高度散光视觉质量的比较

目的比较中高度散光患者配戴框架眼镜和透气性硬性接触镜(RGPCL)的主客观视觉质量。方法选取2008年6月-2011年5月中高度角膜散光20例共40只眼进行角膜地形图、综合验光仪验光等检查后,选择合适试戴片作配适评估并定制RGPCL。要求患者戴镜后1周、1个月、3个月和6个月复查,记录矫正视力、镜片配适、眼部情况,并在第4次复查时进行对比敏感度视力检查及主观问卷调查。结果 RGPCL矫正视力优于框架眼镜,但两者对比敏感度视力在各空间频率均无明显差异。主观评分时,远视力两者无明显差别;中距离视力框架眼镜评分(3.825±0.245)分,RGPCL评分(3.525±0.302)分,差异有统计学意义(t=5.339,P=0.000);近距离视力框架眼镜评分(3.795±0.233)分,RGPCL评分(3.690±0.194)分,差异有统计学意义(t=3.462,P=0.030)。有45%患者选择RGPCL为主要配戴方式;40%患者选择RGP CL和框架眼镜交替使用的方式;10%患者选择仅在有特殊社交需求时使用RGPCL;另5%患者放弃使用RGPCL。结论 RGPCL和框架眼镜矫正中高度角膜散光均能取得较满意效果,在中近距离精细作业时框架眼镜矫正视力更为稳定清晰。但由于RGPCL在成像质量和外观上的优势,多数患者仍愿意坚持配戴RGPCL。     

Orthokeratology lens-related Acanthamoeba keratitis: case report and analytical review

Acanthamoeba keratitis (AK) is a rare but severe ocular infection with a significant risk of vision loss. Contact lens use is the main risk factor for AK. The orthokeratology (OK) lens, a specially designed contact lens, has been used worldwide as an effective method of myopia control. However, the OK lens is associated with an increased risk of Acanthamoeba infection. Many primary practitioners are concerned about this infection because of its relative rarity, the lack of promising therapeutic medications, and the need for referral. We herein report two cases of AK associated with OK lenses, present a systematic review of such cases, and discuss the possible reasons for the higher incidence rate of this infection in patients who wear OK lenses. We combined the clinical knowledge and skills of corneal specialists and lens experts with the sole objective of addressing these OK lens-related AK cases. We found that the most common risk factors were rinsing the lenses or lens cases with tap water. Prompt and accurate diagnosis along with adequate amoebicidal treatment are essential to ensure desirable outcomes for OK lens wearers who develop AK. Appropriate OK lens parameters and regular checkups are also important.     

透氧性硬性角膜接触镜矫治屈光参差性弱视效果观察

目的观察高透氧性硬性角膜接触镜(RGP)治疗青少年屈光参差性弱视的疗效。方法选择2009年4月—2011年12月门诊经规范眼视光学检查,诊断屈光参差性弱视的青少年128例(221眼),其中68例(116眼)纳入观察组,配戴RGP矫正视力;60例(105眼)纳入对照组,配戴框架眼镜,并行增视能弱视训练。观察两组矫正视力后1、3、6、12个月视力,并与治疗前比较。结果随访终点,观察组和对照组有效率分别为67.2%和44.5%(P0.05),1年基本治愈率分别为45.0%和12.3%(P0.05)。观察组未发现严重接触镜并发症。结论 RGP较框架眼镜具有良好的光学优越性,对于屈光参差性儿童弱视可取得良好的治疗效果。     

Extended cyclosporine delivery by silicone-hydrogel contact lenses

Cyclosporine A (CyA) is effective in treating chronic dry eyes and contact lens mediated dry eyes. CyA is delivered through eye drops of an oil-in-water emulsion, which has a small residence time in the eyes, leading to low bioavailability. Here we explore delivery of CyA from contact lenses to provide controlled and extended drug delivery with an increased bioavailability due to enhanced ocular residence time. Loading and release profiles of CyA from commercial contact lenses are presented to show that 1-DAY ACUVUE® releases CyA for about a day and extended wear silicone hydrogel (SiH) lenses release CyA for about 2-weeks. The longer duration from SiH lenses compared to the 1-DAY ACUVUE®lens is due to larger partition coefficients in the gel. A novel approach is presented for increasing release duration from the SiH lenses to the desired 1-month through incorporation of Vitamin E. The results show that Vitamin E loaded lenses can provide CyA release within the therapeutic window for a period of about a month. This pilot study demonstrates the promising potential of delivering CyA from contact lens for treatment of chromic dry eyes and contact lens mediated dry eyes.     

Sustained in vivo release from imprinted therapeutic contact lenses

In this paper, we demonstrate the successful in vivo extended release of a small molecular weight therapeutic, ketotifen fumarate (MW=425), from molecularly imprinted, therapeutic contact lenses. This is the first time that a steady, effective concentration of drug is maintained in the tear film from a contact lens for an extended period of time for the entire duration of lens wear. Poly(HEMA-co-AA-co-AM-co-NVP-co-PEG200DMA) soft contact lenses were prepared (100±5 μm thickness, diameter 11.8 mm, power zero), and a constant tear film concentration of 170±30 μg/mL was measured for up to 26 hrs in a New Zealand white rabbit model. The results showed a dramatic increase in ketotifen mean residence time (MRT) and bioavailability compared to topical drop therapy and drug soaked lenses. The MRT for imprinted lenses was 12.47±3.99 hrs, ~4 and 50 fold greater than non-imprinted lenses and 0.035% eye drops (Zaditor?), respectively. Furthermore, AUC(0-26 hrs) was 9 and 94 fold greater for imprinted lenses than non-imprinted lenses and eye drops, respectively. The results indicate that molecular imprinting provides an exciting rational engineering strategy for sustained release. It is clear that imprinted lenses are very promising combination devices and are much more effective and efficient delivery devices than eye drops.     

Alternatives to standard cataract surgery

Two alternatives to standard cataract surgery have been developed which have distinct benefits in selected patients. Phacoemulsification, which requires only a small incision and little recovery time, is particularly suited to young patients. Elderly patients, who often cannot wear aphakic spectacles or contact lenses, may benefit from intraocular lens implantation.     

The comfort factor: assessing patient satisfaction with Opti-Free vs other contact lens cleaning products

Many patients cite comfort as a primary factor in their success or failure with soft contact lenses. In an effort to further meet the needs of these patients, eye-care professionals must place more emphasis on dispensing a lens type and lens-care system that maximize patient satisfaction and thus provide a higher quality of service. This study delineated patient-defined quality and comfort as they relate to lens-care solutions. Five hundred ninety-nine U.S. practices were each asked to switch 25 of their patients to Opti-Free Lens Care from their currently used lens-care system (52% ReNu Multi-Purpose Solution, 20% AOSept System) for 2 weeks. Data were collected from 14,455 patients who completed the post-trial interview. At the time of the callback interview, 81% of respondents (78% ReNu users, 82% AOSept users) were using the Opti-Free System. Of these patients, 85% (84% previous ReNu users, 87% previous AOSept users) rated Opti-Free Lens Care more comfortable than or as comfortable as their previous system. These findings demonstrate differences in patient comfort among Opti-Free, AOSept, and ReNu. Eye-care professionals should consider relative comfort when dispensing lens-care systems, as this may affect patient-defined quality.     

水凝胶软性亲水接触镜临床应用及安全性

背景：采用水凝胶材料制作而成的Extra-Care软性亲水接触镜含水量、透氧系数、折射率等指标均已达到国家标准。目的：通过与已上市的同类产品TB软性隐形眼镜对比,评价Extra-Care软性亲水接触镜的有效性和安全性。方法：将135例近视眼志愿者随机分入配戴Extra-Care软性亲水接触镜组（试验组）与配戴TB软性隐形眼镜组（对照组）。所有受试者在入选当天、使用7d、使用30d、使用90d时进行视力清晰程度、视力稳定性、配戴舒适度、镜片中心定位、镜片覆盖、眼部异物感、角巩膜缘充血和角膜点状染色及泪膜破裂时间检查。结果与结论：两组视力清晰程度、视力稳定性、镜片中心定位、镜片覆盖、眼部异物感、角巩膜缘充血和角膜点状染色及泪膜破裂时间差异无显著性意义,但试验组舒适度优于对照组（P〈0．05）。表明Extra-Care软性亲水接触镜的临床应用是有效和安全的,并提高了配戴舒适度。     

Fusarium and Candida albicans biofilms on soft contact lenses: model development, influence of lens type, and susceptibility to lens care solutions

Fungal keratitis is commonly caused by Fusarium species and less commonly by Candida species. Recent outbreaks of Fusarium keratitis were associated with contact lens wear and with ReNu with MoistureLoc contact lens care solution, and biofilm formation on contact lens/lens cases was proposed to play a role in this outbreak. However, no in vitro model for contact lens-associated fungal biofilm has been developed. In this study, we developed and characterized in vitro models of biofilm formation on various soft contact lenses using three species of Fusarium and Candida albicans. The contact lenses tested were etafilcon A, galyfilcon A, lotrafilcon A, balafilcon A, alphafilcon A, and polymacon. Our results showed that clinical isolates of Fusarium and C. albicans formed biofilms on all types of lenses tested and that the biofilm architecture varied with the lens type. Moreover, differences in hyphal content and architecture were found between the biofilms formed by these fungi. We also found that two recently isolated keratitis-associated fusaria formed robust biofilms, while the reference ATCC 36031 strain (recommended by the International Organization for Standardization guidelines for testing of disinfectants) failed to form biofilm. Furthermore, using the developed in vitro biofilm model, we showed that phylogenetically diverse planktonic fusaria and Candida were susceptible to MoistureLoc and MultiPlus. However, Fusarium biofilms exhibited reduced susceptibility against these solutions in a species- and time-dependent manner. This in vitro model should provide a better understanding of the biology and pathogenesis of lens-related fungal keratitis.     

两种硅水凝胶角膜接触镜在近视患者LASIK术后早期应用的比较研究

目的比较近视患者接受准分子激光原位角膜磨镶术(LASIK)术后早期佩戴2种硅水凝胶角膜接触镜的上皮修复、术后并发症及眼部不适症状。方法前瞻性选取2019年4月至10月于首都医科大学附属北京友谊医院行LASIK手术的近视患者35例(70眼),采用自身对照,LASIK术后随机给予35眼配戴Lotrafilcon A角膜接触镜,对侧眼配戴Balafilcon A角膜接触镜。术后1 d取出,分别记录术后1、3、7 d的不适症状(疼痛感、干涩和流泪)发生率、术后并发症发生率及角膜荧光素染色(FL)阳性率。对双眼间各项指标进行统计学分析。结果在术后1 d,Lotrafilcon A组无症状率高于Balafilcon A组(77.14%vs.54.29%),差异有统计学意义(P <0.05),在术后3、7 d组间无症状率比较,差异无统计学意义(85.71%vs.80.00%,88.57%vs.91.43%)。Lotrafilcon A组与Balafilcon A组的术后角膜瓣移位皱褶、角膜瓣边缘瘢痕、层间炎症反应等并发症发生率比较(2.86%vs.0,2.86%vs.8.57%,2.86%vs.0),差异无统计学意义(P> 0.05)。在术后1 d,Lotrafilcon A组FL阳性率低于Balafilcon A组(17.14%vs.40.00%),差异有统计学意义(P <0.05),在术后3、7 d组间FL阳性率比较(11.43%vs.14.29%,5.71%vs.8.57%),差异无统计学意义(P>0.05)。结论硅水凝胶角膜接触镜对于缓解眼表刺激症状、促进角膜愈合有显著疗效,适宜于近视患者LASIK术后早期配戴。Lotrafilcon A以及Balafilcon A角膜接触镜在LASIK术后应用是安全有效的,Lotrafilcon A更有助于角膜上皮再生。     

Nasal-temporal asymmetry in peripheral refraction with an aspheric myopia control contact lens

A combination of human subject data and optical modelling was used to investigate unexpected nasal-temporal asymmetry in peripheral refraction with an aspheric myopia control lens. Peripheral refraction was measured with an auto-refractor and an aberrometer. Peripheral refraction with the lens was highly dependent upon instrument and method (e.g. pupil size and the number of aberration orders). A model that did not account for on-eye conformation did not mirror the clinical results, but a model assuming complete lens conformation to the anterior corneal topography accounted for the positive shift in clinically measured refraction at larger nasal field angles. The findings indicate that peripheral refraction of highly aspheric contact lenses is dependent on lens conformation and the method of measurement. These measurement methods must be reported, and care must be used in interpreting results.     

Advances in chemistry and composition of soft materials for drug releasing contact lenses

Ocular drug delivery has always been a challenging feat to achieve in the field of medical sciences. One of the existing methods of non-invasive ocular drug delivery is the use of eye drops. However, drugs administered through these formulations have low bioavailability in the ocular system. This limitation can been overcome by using contact lenses as drug delivery vehicles. According to USA FDA definitions they can be categorized into two main categories-hard and soft contact lenses. Based on the material properties, hard contact lenses are mostly produced from polymers of acrylate monomers such as MMA (methyl methacrylate). These have the least water retention capacity, thereby, having minimal ability to diffuse oxygen into the corneal layer and are not ideal for long term use. Soft material contact lenses are flexible and are mainly hydrogel based. They have higher water retention capacities as compared to rigid contact lenses, which gives them the ability to transmit oxygen to the corneal layer. These hydrogel based soft materials are mainly produced from polymers of acrylate monomers such as HEMA (hydroxyethyl methacrylate) and found to be better for drug delivery contact lenses. These polymer-based soft materials have been efficiently modified in terms of their chemistry to achieve diverse physicochemical properties to produce efficient ocular drug delivery systems. However, complications such as drug leaching during storage and distribution, sterilisation, preservation of integrity of the lens and the possibility of surface roughness due to the incorporated drug molecules still need to be optimised. This review highlights the chemistries of various polymeric molecules through which physicochemical properties can be modified to achieve optimum drug loading and sustained release of the drug for application in the ocular system.

Contact lens as controllable route for ocular drug delivery.     

软性角膜接触镜配戴者相关知识及行为的调查分析

目的探讨配戴软性角膜接触镜(soft contact lens,SCL)者对相关知识及行为状况。方法对200名在本院眼科门诊就诊的SCL配戴者进行SCL相关知识及行为问卷调查,了解SCL配戴者相关知识及行为状况。结果 200名SCL配戴者中73.50%未做眼专科检查直接配戴SCL,18.00%坚持定期复查,87.00%佩戴者不清楚配戴SCL的禁忌症;配戴者对SCL屈光度的选择、分辨镜片正反面知识掌握较好;<6个月组(初戴者)在手部清洁、镜片检查、配戴镜片、镜片清洁4方面戴镜行为正确率明显低于≥6个月组,中专及以下组在使用时间长、戴镜睡觉、手部清洁、镜片清洁4方面戴镜行为正确率明显低于大专及以上组,两组比较,均P<0.05,差异具有统计学意义。结论 SCL配戴者对相关知识了解较少,配戴行为有待改善,尤其初戴和学历较低者。     

农村成年及老年人失牙情况的Logistic回归分析

目的调查我国农村成年和老年人群的失牙原因。方法对北京延庆县古城村20~80岁村民587人的口腔健康状况进行了十年的纵向调查。用Logistic回归分析法预测该组人群失牙的原因。结果年龄、高牙本质龋数、高龋齿数、牙齿附着丧失≥7 mm,牙齿存在动度和低龈下结石沉积位点百分率是有意义的失牙预测因子。龋齿和牙周病同是10年后人群失牙率的重要预测因子;龋齿是失牙的主要预测因子。结论龋齿和牙周病是导致该人群10年后失牙的主要原因。     

Systematic bias in traumatic brain injury outcome studies because of loss to follow-up

OBJECTIVE: To identify potential sources of selection bias created by subjects lost to follow-up in studies of traumatic brain injury (TBI). DESIGN: Demographic, premorbid, injury-related, and hospital course characteristics were compared for subjects lost and found for 1- and 2-year postinjury follow-ups by using bivariate tests and logistic regression analysis. SETTING: Three prospective, longitudinal data sets-a single center, a multicenter, and a statewide incidence surveillance system and follow-up registry. PARTICIPANTS: Adolescents and adults hospitalized with a diagnosis of TBI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects were considered lost when no information was collected from the person with TBI or only limited information could be obtained from a proxy, for any reason, including death, refusal, inability to locate, and inability to interview. RESULTS: At year 1 follow-up, 58.0% to 58.6% of subjects were found; 39.7% to 42.0% of subjects were found by year 2. Variables most frequently associated with loss to follow-up were cause of injury, blood alcohol level, motor function, hospital payer source, and race and ethnicity. CONCLUSIONS: TBI follow-up studies may experience selective attrition of subjects who (1) are socioeconomically disadvantaged, (2) have a history of substance abuse, and (3) have violent injury etiologies. These phenomena are mitigated for those with more severe motor deficits. Loss to follow-up may be a problem inherent to this population; however, the high rate and its selective nature are problematic for outcome studies.     

A minimal intervention program and a problem-solving program for weight control

A clinical replication design was used with seven moderately obese women subjects to investigate the potential of a minimal intervention and problem-solving program in combination and separately. At the end of 1-year follow-up, clinically significant weight losses were achieved; three subjects (43%) reached their calculated ideal weight and the average weight loss was 25.31 pounds. Other major findings included the following: (a) Five subjects (71%) were able to lose weight during the minimal intervention program with little professional assistance; (b) homogeneous weight losses occurred during the problem-solving program (SD = 1.72) and measures of success in problem solving were significantly correlated with measures of weight loss; and (c) weight loss continued after treatment—six subjects (86%) lost weight at 3-month follow-up and three (43%) continued to lose weight at 12-month follow-up. It was concluded that the minimal intervention program might be used as an initial step in a stepped approach to weight management. Problem solving may be an important cognitive treatment component in behavioral weight control programs. Pounds lost may not be an accurate indication of the efficacy of a treatment program because asymptote can occur when a high proportion of subjects reach ideal weight, and therefore, percentage overweight should be considered the main dependent measure in weight-control studies.     

Contact lens alternatives to laser vision correction

As is evident from the various options discussed, patients have endless choices to correct their vision--everything from refractive surgery to high-tech contact lenses to the latest innovations in glasses. People who do not want to wear glasses can select from a wide assortment of contact lenses that provide exceptional vision, comfort, and convenience at an affordable price. Patients who never could wear contact lenses before because of having dry eyes or astigmatism or needing bifocals now can wear them because of advances in medical technology. In addition, patients who do not want to wear either glasses or contact lenses can opt for refractive surgery to correct their vision. The goal of this article is not to push patients towards any particular route but to let them know of all the choices available. Patients must weigh all of the options, including cost, convenience, and long-term stability, and then make a choice. As with anything else, nothing is without risk or price. It is up to each individual patient to weigh the risks and benefits and decide what option to choose. The best thing for a patient to do when considering any of these options is to make an appointment with his or her eye doctor and together make an informed decision about which option is the best for the patient.