Tear film measurements in four different ethnic groups: Malay, Chinese, Indian and Nigerian

AIM: To compare the non-invasive tear film break-up time (NIBUT), tear break up time (TBUT), basal tear secretion (BTS) and blink rate in four ethnic groups: Malay, Chinese, Indian and Nigerian. METHODS: Totally 120 healthy (61 males and 59 females) subjects (without dry eye symptoms and ocular surface disorder) with the age 20 to 39 years were recruited; 30 were Malays, 30 were Chinese, 31 were Indians and 29 were Nigerians. Based on McMonnies questionnaire and clinical examination, normal subjects were selected. NIBUT, TBUT, BTS were assessed in only one eye (right) of each subject and blink rate was also assessed. RESULTS: There was significant difference in the NIBUT, TBUT, BTS and blink rate among 4 different ethnic groups (P=0.018, 0.001, 0.011, and 0.004 respectively). No statistically significant difference of NIBUT, TBUT, BTS and blink rate was found between the genders among different ethnic groups. Indian had higher median for NIBUT (10±6s), TBUT (7±5s) and BTS (20±20 mm) than other races. Chinese had lower median for NIBUT (7.5±4s) and TBUT (4±2s) while Malay had for BTS (9.5±16 mm) among the groups. There was no significant correlation of blink rate with NIBUT (r=-0.119, P=0.195), TBUT (r=-0.086, P=0.352), and BTS (r=-0.123, P=0.180) respectively. CONCLUSION: The tear-film measurement values are variability in four ethnic groups.     

湖北省7台医用直线加速器调强放射治疗多叶光栅叶片到位精度验证方法研究

目的 用放射性免冲洗胶片测量调强放射治疗（IMRT）多叶光栅（MLC）叶片到位精确度验证方法研究,为IMRT质量控制提供参考依据。方法 选择湖北省7家三甲医院的7台不同型号医用直线加速器,放射治疗计划系统（TPS）计划5条宽度为0.6 cm条状的栅栏,每条状野之间的距离为3.0 cm。用EBT2免冲洗胶片测量5条状野位置、多叶光栅叶片位置偏差和实际宽度。结果 按国际原子能机构（IAEA）要求,胶片测量与TPS计划每条栅栏野多叶光栅条状位置结果应≤±0.5 mm。编号5和编号7的加速器MLC条状野位置偏差分别为0.7和-1.0 mm,不符合IAEA要求。按IAEA要求,胶片测量每对与每条所有多叶光栅叶片平均位置偏差应≤±0.5 mm。7台加速器MLC每对叶片位置偏差均在±0.5 mm内,符合IAEA要求;IAEA要求单对MLC叶片开野宽度与该机器5条条状野平均开野宽度的差值不超过±0.75 mm,7台加速器每对MLC开野宽度与平均值的差值范围为-0.6~0.5 mm,符合要求。所有叶片开野宽度标准偏差应≤0.3 mm,7台加速器标准偏差在0.1~0.2 mm范围内,符合要求。结论 用EBT2免冲洗胶片验证MLC位置精确度方法操作简单、检测精度高,是质量控制（QA）的重要手段之一,适合大范围核查使用。     

水胶体透明敷料预防神经外科中心静脉导管细菌定植和细菌感染的研究

目的比较透明薄膜敷料与水胶体透明敷料预防神经外科中心静脉导管细菌定植和细菌感染的效果,为合理选择中心静脉导管固定敷料提供依据。方法按照随机数字表法将神经外科行中心静脉置管患者470例分为对照组(230例)和观察组(240例),中心静脉置管后对照组采用透明薄膜敷料固定导管,观察组采用水胶体透明敷料固定导管。比较两组导管病原菌定植、导管相关性感染和导管相关性血源性感染、皮肤病原菌定植情况。结果观察组导管病原菌定植、导管相关性感染、导管相关性血源性感染以及皮肤病原菌定植的发生率显著低于对照组,导管感染发生时间显著延长(均P0.05)。结论水胶体透明敷料可以有效预防神经外科患者中心静脉导管细菌定植和细菌感染,具有良好的皮肤安全性。     

PVA-PEG physically cross-linked hydrogel film as a wound dressing: experimental design and optimization

The development of hydrogel films as wound healing dressings is of a great interest owing to their biological tissue-like nature. Polyvinyl alcohol/polyethylene glycol (PVA/PEG) hydrogels loaded with asiaticoside, a standardized rich fraction of Centella asiatica, were successfully developed using the freeze–thaw method. Response surface methodology with Box–Behnken experimental design was employed to optimize the hydrogels. The hydrogels were characterized and optimized by gel fraction, swelling behavior, water vapor transmission rate and mechanical strength. The formulation with 8% PVA, 5% PEG 400 and five consecutive freeze–thaw cycles was selected as the optimized formulation and was further characterized by its drug release, rheological study, morphology, cytotoxicity and microbial studies. The optimized formulation showed more than 90% drug release at 12?hours. The rheological properties exhibited that the formulation has viscoelastic behavior and remains stable upon storage. Cell culture studies confirmed the biocompatible nature of the optimized hydrogel formulation. In the microbial limit tests, the optimized hydrogel showed no microbial growth. The developed optimized PVA/PEG hydrogel using freeze–thaw method was swellable, elastic, safe, and it can be considered as a promising new wound dressing formulation.     

基于X线片的十二等分法评估全椎弓根螺钉固定矫形术治疗青少年特发性脊柱侧凸的置钉准确性

目的 :利用基于X线片的十二等分法评估单纯后路全椎弓根螺钉固定矫形术治疗青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)的置钉准确性。方法:回顾性分析我科行单纯后路全椎弓根螺钉固定矫形术治疗的AIS患者40例(女性34例,男性6例),年龄15.2±1.9岁(11～18岁),分别采用传统方法和十二等分法在X线片上评估椎弓根螺钉置钉准确性,并通过CT平扫验证。传统方法:A级,螺钉钉尖在椎弓根内壁和椎体中线之间,且与相邻螺钉相比无明显偏内或偏外;B级,螺钉钉尖超越椎体中线或与相邻螺钉相比明显偏内;C级,螺钉钉尖在椎弓根内壁以外或与相邻螺钉相比明显偏外。十二等分法:将椎体由凹侧外侧缘及凸侧外侧缘向分别正中线画等分线分12等份,并根据螺钉钉尖在所在椎体上的位置和椎体旋转的程度确定相应的安全范围。A级,螺钉钉尖在安全范围内;B级,螺钉钉尖超出安全范围内界或与相邻螺钉相比明显偏内;C级,螺钉钉尖超出安全范围外界或与相邻螺钉相比明显偏外。CT平扫:A级,螺钉全部在椎弓根内;B级,螺钉有任何部分超出椎弓根内壁;C级,螺钉有任何部分超出椎弓根外壁。通过卡方检验和诊断试验结果法对比两种X线片评估方法的准确性。结果:CT平扫评估,638枚螺钉中595枚(93.3%)A级,9枚(1.4%)B级,34枚(5.3%)C级;十二等分法,589枚(92.3%)A级,10枚(1.6%)B级,39枚(6.1%)C级;传统方法 ,582枚(91.2%)A级,19枚(3.0%)B级,37枚(5.8%)C级。使用传统方法误判螺钉49枚(7.7%)枚,十二等分法误判螺钉14枚(2.2%)枚,二者有显著差异(P0.001),其中B级误判的螺钉分别为25枚(3.9%)和5枚(0.8%)(P0.001),C级误判的螺钉分别为24枚(3.8%)和9枚(1.4%)(P=0.006)。此外,使用传统方法和十二等分法,评估凹侧椎弓根置钉的误判率高于凸侧,评估旋转较大椎体置钉的误判率高于旋转较小的椎体。结论:在X线片上采用十二等分法评估AIS患者的置钉情况简便、可靠,可以提高评估螺钉置钉的准确性。     

环境烟草烟雾对小鼠泪膜功能和角膜上皮组织结构的影响

目的　探讨环境烟草烟雾（enviromental tobacco smoke,ETS）对小鼠泪膜功能和角膜上皮组织结构的影响。方法　选取SPF级c57BL雄性小鼠12只,随机分为对照组和ETS干预组,每组6只。对照组不进行ETS干预,ETS干预组进行ETS干预,每天2次,一次30 min,干预12周。在干预前及干预后对各组小鼠进行泪膜功能检测,包括泪膜破裂时间、荧光素染色(FL)评分;干预后摘取小鼠角膜组织,行HE染色,在光学显微镜下观察小鼠角膜上皮结构变化情况。结果　干预12周后,对照组泪膜破裂时间和FL评分与干预前相比,差异均无统计学意义(均为P>0.05);而ETS干预组泪膜破裂时间较干预前明显缩短,FL评分较干预前明显增加,差异均有统计学意义（均为P<0.05)。ETS干预组干预12周后泪膜破裂时间较对照组明显缩短,FL评分较对照组明显增加,差异均有统计学意义(均为P<0.05);两组干预前泪膜破裂时间和FL评分差异均不明显（均为P>0.05）。FL染色结果显示:干预12周后,对照组小鼠角膜上皮完整,角膜染色呈阴性;ETS干预组整个角膜上皮荧光素着染区域明显增加,呈点片状。HE染色结果显示:干预12周后,对照组未见角膜上皮层数的改变,厚度也基本未变,基底细胞仍为单层柱状上皮细胞,表层上皮较完整;ETS干预组可见角膜上皮细胞层数增多,厚度增加,细胞排列紊乱,表层上皮细胞有损失及脱落,角膜表面不光滑。干预前对照组小鼠上皮细胞为（5±1）层,干预后基本不变;ETS干预组干预后为（7±1）层;干预后两组上皮细胞层数比较差异有统计学意义（P＜0.05）。结论　ETS会影响小鼠泪膜功能,损伤小鼠角膜上皮的组织结构。     

Characterising the ocular surface and tear film in a population-based birth cohort of 45-year old New Zealand men and women

PurposeTo assess the prevalence of dry eye disease, aqueous tear deficiency, meibomian gland dysfunction, and asymptomatic ocular surface disease in a population-based cohort of 45-year-old New Zealand men and women.MethodsThis cross-sectional study of 885 participants (442 females, 443 males) was based on a population-representative birth cohort of individuals born between April 1 1972 and March 31 1973 in Dunedin, New Zealand (the Dunedin Multidisciplinary Health and Developmental Study). Participants were assessed at 45 years of age, and dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session. The diagnosis of dry eye disease was made according to the validated rapid non-invasive dry eye assessment algorithm.ResultsClinical dry eye signs were present in 402 (45%) participants, of which 78 (9%) participants fulfilled the diagnostic criteria for dry eye disease, and 322 (37%) had asymptomatic ocular surface disease. Among participants with dry eye disease, 22 (2%) exhibited aqueous tear deficiency, and 65 (7%) had meibomian gland dysfunction. Females were more likely to be affected by dry eye disease, meibomian gland dysfunction, and asymptomatic ocular surface disease (all p < 0.05).ConclusionsClinical dry eye signs were present in almost half of this population-based cohort of 45-year-old New Zealanders, although only 9% of participants fulfilled the diagnostic criteria for dry eye disease. The high prevalence of asymptomatic ocular surface disease presents an opportunity for preventative public health intervention.     

Randomized masked trial of the clinical efficacy of MGO Manuka Honey microemulsion eye cream for the treatment of blepharitis

PurposeTo assess the clinical efficacy of a novel MGO Manuka Honey microemulsion (MHME) eye cream for the management of blepharitis.MethodsFifty-three participants (32 females, 21 males; mean ± SD age, 60 ± 12 years) with clinical signs of blepharitis were enrolled in a prospective, investigator-masked, randomized, paired-eye trial. The MHME eye cream (Manuka Health New Zealand) was applied to the closed eyelids of one eye (randomized) overnight for 3 months. Visual acuity, ocular surface characteristics, symptoms and tear film parameters were assessed at baseline, day 30, and day 90. Eyelid swab microbiology cultures were evaluated at baseline and day 90.ResultsBaseline measurements did not differ between treated and control eyes (all p > 0.05). Significant reductions in SANDE and SPEED symptomology scores were detected in treated eyes on days 30 and 90 (all p < 0.05), while clinical improvements in non-invasive tear film breakup time, lipid layer thickness, and inferior lid wiper epitheliopathy were observed on day 90 (all p < 0.05). Following the 3-month treatment period, ocular Demodex, Corynebacterium macginleyi, Propionibacterium acnes, and Staphylococcus epidermidis load decreased significantly in treated eyes (all p ≤ 0.001). There were no changes in visual acuity during the 90-day period (all p > 0.05), and no major adverse events were reported.ConclusionTopical overnight application of the MHME eye cream effected significant improvements in ocular surface symptomology, tear film stability and lipid layer thickness, and reduced lid margin staining, ocular Demodex and bacterial load. The favourable clinical efficacy and tolerability profile suggests promise for the MHME eye cream as a treatment for blepharitis management.Trial registration numberACTRN12616000539437.     

Evaluation of use of essential fatty acids in topical ophthalmic preparations for dry eye

PurposeEssential fatty acids (EFAs) as dietary supplements are used in treating dry-eye for reducing inflammation at the ocular surface. Their topical application in eye drops to deliver fatty acid (FA) directly to the ocular surface requires thorough investigation. Being lipids in nature EFAs can interact with tear lipids and affect tear stability. This study aimed at investigating the biophysical interactions of EFAs with Meibomian lipids.MethodsRheology of mixtures of Human Meibomian lipids with EFAs (LA-linoleic acid, ALA-alpha-linolenic acid), OA (oleic acid), and GLA (gamma-linolenic acid) was studied using Langmuir trough technology on an artificial tear solution at the ocular surface temperature. Pressure-area profiles were used to determine compressibility and elasticity of the mixed films.ResultsLA enhanced spreading of Meibomian lipids and increased their compressibility and elasticity which can be beneficial for tear stability. ALA condensed Meibomian lipids film with less elasticity deemed unfavourable for tear stability. OA expanded Meibomian lipids but decreased elasticity at high compressions making films less stable. GLA had little or no favourable effect on tear stability. Higher concentrations of FAs made films less stable.ConclusionsEFAs or OA in topical ophthalmic preparations can affect spread and stability of the tear film lipid layer. Rheology of mixed films should be tested using Langmuir trough technology to determine suitable type and amount of a lipid additive for therapeutic eye drops. In topical applications, the omega-6 LA (not omega-3 FA) at low concentrations (20 mol%) can be beneficial for enhancing tear stability in dry eye patients.     

Randomised double-masked placebo-controlled trial of the cumulative treatment efficacy profile of intense pulsed light therapy for meibomian gland dysfunction

PurposeTo assess long-term cumulative treatment effects of intense pulsed light (IPL) therapy in meibomian gland dysfunction (MGD).MethodsEighty-seven symptomatic participants (58 female, mean ± SD age, 53 ± 16 years) with clinical signs of MGD were enrolled in a prospective, double-masked, parallel-group, randomised, placebo-controlled trial. Participants were randomised to receive either four or five homogeneously sequenced light pulses or placebo treatment to both eyes, (E-Eye Intense Regulated Pulsed Light, E-Swin, France). Visual acuity, dry eye symptomology, tear film parameters, and ocular surface characteristics were assessed immediately before treatment on days 0, 15, 45, 75, and four weeks after treatment course completion on day 105. Inflammatory and goblet cell function marker expression, and eyelid swab microbiology cultures were evaluated at baseline and day 105.ResultsSignificant decreases in OSDI, SPEED, and SANDE symptomology scores, and meibomian gland capping, accompanied by increased tear film lipid layer thickness, and inhibited Corynebacterium macginleyi growth were observed in both treatment groups (all p < 0.05). Sustained clinical improvements occurred in both treatment groups from day 75, although significant changes from day 45, in lipid layer quality, meibomian gland capping, OSDI and SANDE symptomology, were limited to the five-flash group (all p < 0.05).ConclusionsIPL therapy effected significant improvements in dry eye symptomology, tear film lipid layer thickness, and meibomian gland capping in MGD patients. Five-flash IPL treatment showed superior clinical efficacy to four-flash, and an initial course of at least four treatments is suggested to allow for establishment of sustained cumulative therapeutic benefits prior to evaluation of overall treatment efficacy.Trial registration numberACTRN12616000667415.