Can possible toxic effect of ultraviolet-A after corneal cross-linking be prevented? In vitro transmittance study of contact lenses at 370 nm wavelength

Context: Corneal collagen cross linking (CCL) with ultraviolet A (UVA) has been proposed as a treatment for the progression of corneal ectasia associated with keratoconus and post-laser-assisted in situ keratomileusis (LASIK) ectasia. Despite the reports about safety of procedure, we consider that UVA of sunlight can effect riboflavin saturated and de-epitelizated cornea early after CCL.

Objectives: To evaluate the UVA blockage capability of 11 different silicone hydrogel contact lenses which are widely used after CCL treatment.

Methods: Eleven different silicone hydrogel and daily disposable contact lenses were evaluated. The UVA light at 365?nm wavelength for UVA source and UV light meter to measure UVA radiation were used. 3, 9 and 18?mW/cm² power of UV radiance was applied centrally to the each type of contact lenses. The power of UVA transmittance for each radiance and percentage of blockage were evaluated for each brand. Also, protection factor (PF) was calculated.

Results: The senofilcon A and narafilcon A had the highest blockage and lowest transmittance (p?=?0.02). PF was significantly higher in the senofilcon A and narafilcon A at 3, 9 and 18?mW/cm² (p?=?0.0001). And also, the hilafilcon B, filcon IV, nelfilcon A, enfilcon A, lotrafilcon A and lotrafilcon B had the highest UVA transmittance.

Conclusion: The narafilcon A and the senofilcon A may be a good options for epithelial healing after CCL procedure to protect the cornea from UVA of sunlight. And also, the hilafilcon B, filcon IV, nelfilcon A, enfilcon A, lotrafilcon A and lotrafilcon B contact lenses that have high-UVA transmittance feature can be a treatment choice for contact lens-assisted CCL technique in thin corneas.     

Corneal epithelial stem cells for corneal injury

Introduction: Ocular surface diseases with limbal insufficiency represent a therapeutic challenge for restoring vision. This corneal deficiency includes both classical ocular diseases (as chemical burns) and rare ocular diseases (as congenital aniridia and ocular cicatricial pemphigoid).

Areas covered: Our understanding of limbal epithelial stem cells (LESCs) has increased the potential for treatment options. Pharmacological treatment strategies (as regenerating agent ophthalmic solutions) and especially surgical treatment strategies are available. Isolated LESCs can be produced by limbal primary cultures obtained from explants or cell suspensions. We review the latest cornea surgery techniques.

Expert opinion: The adjunction of human limbal mesenchymal cells as a support for limbal stem cell primary cultures appears to be of great interest. Recently, human-induced pluripotent stem cells have allowed the generation of minicorneal organoids. This potential means of creating a three-dimensional cornea with in vitro maturation opens up important research areas for corneal regeneration therapy.     

强化护理健康教育对行准分子激光上皮瓣下角膜磨镶术近视患者的效果分析

[摘要]目的 分析强化护理健康教育对接受准分子激光上皮瓣下角膜磨镶术的近视患者的术后用药依从性和视觉满意度的影响。方法 选择2015年3月-2015年9月在我院45例接受常规健康教育的行准分子激光上皮瓣下角膜磨镶术近视患者,将其作为对照组;再选取2015年10月-2016年3月接受强化护理健康教育的行准分子激光上皮瓣下角膜磨镶术近视患者作为观察组。对比两组患者术后用药的依从性情况,同时比较两组患者术后的视觉满意度。结果 观察组患者的用药依从率为91.1%,对照组患者的用药依从率为68.9%,差异有统计学意义(P＜0.05)。观察组患者的视觉满意度为100.0%,对照组患者的视觉满意度为84.4%,差异有统计学意义(P＜0.05)。结论 强化护理健康教育应用于行准分子激光上皮瓣下角膜磨镶术的近视患者中,能够提高患者的用药依从性,增强患者的视觉满意度,值得临床进一步推广应用。     

Evaluating the change in central corneal thickness in neonates (term and preterm) in Indian population and the factors affecting it

Background and Aim:

Central corneal thickness (CCT) of term and preterm infants in Indian population is not known. We did a prospective noninterventional study to measure the CCT in term and preterm infants.

Materials and Methods:

An ultrasonic pachymeter was used. The data regarding the date of birth, expected date of delivery, birth weight were recorded. The preterm and the term infants were followed up at 8 weeks, 20 weeks and at 1-year.

Results:

A total of 85 (170 eyes) children were included in the study. The mean age was 264.6 ± 21.8 days postconception. The mean birth weight and CCT were 1834.4 ± 512.1 g and 595.8 ± 72.4 μ respectively. A comparison of CCT on the basis postgestational age showed a mean thickness of 620.7 ± 88.8 and 574.4 ± 78.3 μ in the <260 days and >260 days age groups respectively. The difference was statistically significant (Student''s test, P = 0.002). The CCT of preterm infants (<260 days) decreased from a mean value of 620.7 ± 88.8 μ to 534.1 ± 57.6 μ at the end of 1-year.

Conclusion:

We present the data of CCT in term and preterm infants in Indian population. We believe that the premature babies have slightly thicker corneas than mature term babies.     

A cross-sectional study to compare intraocular pressure measurement by sequential use of Goldman applanation tonometry,dynamic contour tonometry,ocular response analyzer,and Corvis ST

Objective:

To study the correlation and effect of sequential measurement of intraocular pressure (IOP) with Goldmann applanation tonometer (GAT), ocular response analyzer (ORA), dynamic contour tonometer (DCT), and Corvis ST.

Setting and Design:

Observational cross-sectional series from the comprehensive clinic of a tertiary eye care center seen during December 2012.

Methods:

One hundred and twenty-five study eyes of 125 patients with normal IOP and biomechanical properties underwent IOP measurement on GAT, DCT, ORA, and Corvis ST; in four different sequences. Patients with high refractive errors, recent surgeries, glaucoma, and corneal disorders were excluded so as to rule out patients with evident altered corneal biomechanics.

Statistical Analysis:

Linear regression and Bland–Altman using MedCalc software.

Results:

Multivariate analysis of variance with repeated measures showed no influence of sequence of device use on IOP (P = 0.85). Linear regression r² between GAT and Corvis ST, Corvis ST and Goldmann-correlated IOP (IOPg), and DCT and Corvis ST were 0.37 (P = 0.675), 0.63 (P = 0.607), and 0.19 (P = 0.708), respectively. The Bland–Altman agreement of Corvis ST with GAT, corneal compensated IOP, and IOPg was 2 mmHg (−5.0 to + 10.3), −0.5 mmHg (−8.1 to 7.1), and 0.5 mmHg (−6.2 to 7.1), respectively. Intraclass correlation coefficient for repeatability ranged from 0.81 to 0.96.

Conclusions:

Correlation between Corvis ST and ORA was found to be good and not so with GAT. However, agreement between the devices was statistically insignificant, and no influence of sequence was observed.     

细菌性角膜溃疡误诊原因及预后分析

目的研究细菌性角膜溃疡的特点,分析引起误诊的原因,探讨影响患者预后的相关因素。方法回顾性分析。以2011年1月至2013年12月间山东省眼科医院收治的83例(83只眼)确诊为细菌性角膜溃疡的患者作为研究对象。通过统计患者误诊疾病、发病诱因、眼部临床表现、就诊医院、所行辅助检查等,分析误诊原因。通过统计不同确诊时间的患者药物、手术治疗的情况,分析误诊患者确诊前病程与其预后的关系。结果 83例患者的发病诱因中49例有各种角膜外伤史,包括植物性外伤22例(占26.5%)。42例患者眼部临床表现为病史迁延、病灶边界不清,伴类似伪足或类似卫星灶、类似内皮斑等。33例患者于首诊医院误诊,误诊疾病分别为真菌性角膜炎28例(占33.7%)、病毒性角膜炎5例(占6.0%)。首诊医院为省市级医院的误诊率为29.3%,县级及以下医院的误诊率为50.0%。省市级医院行角膜刮片及培养者占70.7%,刮片阳性率27.6%。县级及以下医院行实验室检查者仅占30.1%,刮片阳性率15.4%。预后:误诊患者中确诊前病程≤2周者药物治愈6例(占30.0%),行角膜病灶切除治愈4例(占20.0%),行角膜移植治愈10例(50.0%),总治愈率100%。病程大于2周者,药物治愈2例(占15.4%),行角膜病灶切除治愈3例(占23.1%),行角膜移植治愈6例(46.1%),行眼内容剜除2例(占15.4%),总治愈率84.6%。结论目前细菌性角膜溃疡的误诊率仍较高,普及严格、规范的实验室检测结合其他辅助检查能有效降低误诊率。早确诊、早治疗有助于改善误诊患者预后。     

超声乳化白内障吸除术中对向角膜切口矫正术前角膜散光的临床观察

目的 观察导航系统引导下超声乳化白内障吸除术中在角膜曲率最大子午线上行对向透明角膜切口矫正术前角膜散光的临床疗效.方法 队列研究.选择35例(40眼)术前角膜散光度均大于1.0 D白内障患者为实验组,在表面麻醉下于最大角膜曲率子午线上做2.8 mm对向透明角膜切口;另选27例(30眼)术前角膜散光度均大于1.0 D白内障患者为对照组,在表面麻醉下于最大角膜曲率子午线上做2.8 mm单个透明角膜切口.观察2组术前及术后3个月角膜散光度及平均角膜曲率的变化.根据Jaffe's矢量分析原理计算手术源性角膜散光,采用独立样本t检验与配对t检验进行数据分析.结果 对照组术前及术后3个月角膜散光度分别为(1.84±0.40)D和(1.49±0.36)D,差异有统计学意义(t=7.55,P＜0.05).实验组分别为(1.89±0.74)D和(0.71±0.60)D,差异有统计学意义(t=13.93,P＜0.05).术后3个月2组角膜散光度相比差异有统计学意义(t=-6.31,P＜0.05).2组手术源性散光分别为(0.38±0.18)D和(1.55±0.84)D.对照组术前及术后3个月平均角膜曲率分别为(44.18±1.31)D和(44.14±1.31)D,差异无统计学意义(t=1.21,P＞0.05).实验组分别为(44.33±1.51)D和(44.29±1.52)D,差异无统计学意义(t=0.73,P＞0.05).结论 超声乳化吸除术中行对向透明角膜切口是一种安全、有效的矫正角膜散光的方法.