复方托吡卡胺对中央角膜厚度测量的影响

目的：评价复方托吡卡胺眼液对中央角膜厚度测量的影响及影响持续的时间。方法选择拟行激光角膜屈光手术的近视眼患者120例240眼,分别于点眼前和点眼后1,4 h 用 OrbscanⅡ眼前节检查系统和非接触反射显微镜SP－2000P测量角膜厚度。结果以OrbscanⅡ测量复方托吡卡胺点眼前、点眼后1 h、点眼后4 h中央角膜厚度（CCT）分别为（545±27）,（559±31）,（544±26）μm;以SP－2000P测量分别为（508±26）,（521±29）,（506±24）μm。复方托吡卡胺点眼后1 h与点眼前与相比,2种仪器测量CCT均增加（ P＜0．01）;复方托吡卡胺点眼后4 h 与点眼后1 h 相比,2种仪器测量 CCT 均下降（ P ＜0．01）;复方托吡卡胺点眼后4 h与点眼前相比,CCT均无变化。结论复方托吡卡胺点眼1 h后使CCT增加;复方托吡卡胺对CCT影响在点眼4 h后消除。准分子激光屈光手术术前检查中,CCT的测量应在复方托吡卡胺点眼前或者点眼后4h进行。     

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.     

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.     

糖尿病大鼠角膜上皮损伤修复过程中 occludin 的重塑特点

目的：探讨糖尿病（DM）大鼠和正常大鼠角膜上皮修复过程中紧密连接蛋白 occludin 重塑的特点。方法90只 SD 大鼠随机分为 DM组和正常对照组（NC）各45只（DM组均高脂喂养）,通过腹腔注射链脲佐菌素（STZ）诱导形成Ⅱ型 DM大鼠模型,于损伤后0 h（未损伤）,16、48、72、120 h （每组5只）处死大鼠取角膜。间接免疫荧光染色和 Western blot 法观察 occludin 蛋白在损伤修复过程中的变化。结果DM大鼠角膜上皮损伤愈合率较 NC 组大鼠明显延迟,DM组和 NC 组大鼠角膜上皮 occludin 蛋白在损伤后16、48 h 表达差异有统计学意义（P ＜0．05）,在损伤后0、72、120 h 表达差异无统计学意义。结论糖尿病可影响大鼠角膜上皮创伤修复过程中紧密连接蛋白 occludin 蛋白的表达。     

3种环糊精对姜黄素角膜渗透性影响研究

目的研究β-环糊精(β-CD)、羟丙基-β-环糊精(HP-β-CD)和磺丁基醚-β-环糊精(SBE-β-CD)对姜黄素离体角膜渗透作用的影响。方法采用改良Franz扩散池,以离体角膜扩散实验考察不同质量分数的3种环糊精对姜黄素角膜渗透性的影响。结果β-CD质量分数为0.02%、0.04%、0.06%、0.08%时,姜黄素的角膜表观渗透系数分别增加了1.06、1.03、1.00、0.95倍,同质量分数的HP-β-CD分别增加了1.16、1.19、1.17、1.12倍,质量分数为0.04%、0.06%时,与对照组相比有显著差异(P0.05);同质量分数的SBE-β-CD分别增加了1.06、1.23、1.08、0.90倍,质量分数为0.04%时,与对照组相比有显著差异(P0.05)。以质量分数为0.06%的SBE-β-CD作为促渗剂,姜黄素释放曲线符合零级释放方程(r=0.997 8);角膜水化平均为81.7%。结论 HP-β-CD质量分数为0.04%、0.06%,分别增加表观渗透系数1.19、1.17倍(P0.05);SBE-β-CD为0.04%时,增加1.23倍(P0.05)。SBE-β-CD作为眼用促渗剂使药物的释放过程更加安全有效;3种环糊精促渗剂对角膜无刺激。     

绷带镜治疗糖尿病患者玻璃体切割术后角膜上皮缺损的临床观察

目的分析糖尿病患者玻璃体切除术后角膜上皮缺损的临床特征,观察绷带镜治疗这类并发症的疗效。方法收集糖尿病患者行玻璃体切除术后角膜上皮缺损的病例共36例,均采用绷带镜进行治疗。结果36例患者均在接受绷带镜治疗后的不同时间内症状得到缓解,角膜上皮愈合,视觉质量提高。结论绷带镜可有效治疗糖尿病患者玻璃体切除术后角膜上皮的缺损,提高患者视觉质量。     

Effect of diet‐induced obesity or type 1 or type 2 diabetes on corneal nerves and peripheral neuropathy in C57Bl/6J mice

We determined the impact diet‐induced obesity (DIO) and types 1 and 2 diabetes have on peripheral neuropathy with emphasis on corneal nerve structural changes in C57Bl/6J mice. Endpoints examined included nerve conduction velocity, response to thermal and mechanical stimuli and innervation of the skin and cornea. DIO mice and to a greater extent type 2 diabetic mice were insulin resistant. DIO and both types 1 and 2 diabetic mice developed motor and sensory nerve conduction deficits. In the cornea of DIO and type 2 diabetic mice there was a decrease in sub‐epithelial corneal nerves, innervation of the corneal epithelium, and corneal sensitivity. Type 1 diabetic mice did not present with any significant changes in corneal nerve structure until after 20 weeks of hyperglycemia. DIO and type 2 diabetic mice developed corneal structural damage more rapidly than type 1 diabetic mice although hemoglobin A₁C values were significantly higher in type 1 diabetic mice. This suggests that DIO with or without hyperglycemia contributes to development and progression of peripheral neuropathy and nerve structural damage in the cornea.     

Comparison of the Astigmatic Power of Toric Intraocular Lenses Using Three Toric Calculators

Purpose

To compare the astigmatic power of toric intraocular lenses (IOLs) obtained from the AcrySof, TECNIS, and iTrace toric calculator in patients with preoperative with-the-rule (WTR) or against-the-rule (ATR) corneal astigmatism.

Materials and Methods

Fifty eyes with cataract and corneal astigmatism greater than 0.75 diopters were enrolled in each group (WTR and ATR). Keratometric values were measured using autokeratometry, an IOLMaster, and an iTrace, which incorporated corneal topography and ray-tracing aberrometry. Based on measured keratometric values, the astigmatic power of each toric IOL was calculated using three toric calculators.

Results

Bland-Altman plots showed good agreement between six pairwise corneal astigmatism values in both groups. The TECNIS calculator tended to suggest a higher astigmatic power of the toric IOL than the AcrySof calculator. With the higher astigmatism and keratometric values from the IOLMaster, in both groups, calculations from the AcrySof and TECNIS calculators resulted in higher calculated astigmatic powers than those from same calculators with autokeratometry-measured values, demonstrating good agreement. With the higher calculated astigmatic power values, the values from the iTrace toric calculator using keratometric values obtained from iTrace ray tracing wavefront aberrometry or iTrace simulated keratometry showed fair to moderate agreement with those from the other calculator-keratometry pairs in both groups.

Conclusion

To achieve the best refractive outcome after toric IOL implantation, understanding the differences in keratometric values between instruments and in calculated astigmatic power among toric calculator programs is necessary. Moreover, systemic analysis of each toric calculator in conjunction with postoperative data is required.     

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.