A review of the development of a synthetic corneal onlay for refractive correction

A synthetic corneal onlay, or implantable contact lens, could obviate the need for spectacles or conventional contact lenses in patients who seek convenient, reversible correction of refractive error. Several research groups have attempted to develop such a product in the past but much of the data from these studies remains unpublished due to commercial interests. This article reviews relevant papers and patents in the corneal implant field and discusses our efforts to develop a synthetic corneal onlay using a perfluoropolyether-based polymer.     

两种非接触眼压计临床应用效果及其关联因素的临床研究

目的探讨两种非接触眼压计测量的眼压(IOP)值之间的关联性及一致性，及其与中央角膜厚度(CCT)、陡峭角膜曲率(Ks)和平坦角膜曲率(Kf)的关联性。 方法横断面研究。收集2018年3月至2018年4月在首都医科大学附属北京同仁医院眼科屈光中心招募的71例(142只眼)健康志愿者的眼科资料，依次使用CanonTX20型非接触气动眼压计测量IOP，VX120型多参数测量系统测量IOP、校正IOP及CCT，角膜地形图测量Ks、Kf。采用Wilcoxon秩和检验分析两种非接触眼压计测量的IOP值之间的关联性及一致性。应用Spearman相关分析分析非接触眼压计测量的IOP值与CCT、Ks和Kf的相关性；应用Bland-Altman以及95%的一致性界限(LoA)分析两种非接触眼压测量计的一致性。 结果CanonTX20、VX120测量的IOP和校正后的VX120测量的IOP分别为(15.7±2.5)mmHg(1 mmHg＝0.133 kPa)、(16.7±3.4)mmHg、(16.8±3.3)mmHg，其不同性别间的差异无统计学意义(Z＝0.295，0.366，0.131；P>0.05)。VX120测量的IOP值比CanonTX20测量的IOP值高(1.007±2.651)mmHg，两者之间差异有统计学意义(t＝-4.527，P<0.05)。CanonTX20、VX120测量的IOP分别与VX120、Lenstar LS900测量的CCT有相关性(r＝0.177，0.167，0.221，0.178；P<0.05)。校正后的VX120测量的IOP和VX120、Lenstar LS900测量的CCT无相关性(r＝0.026，-0.001，0.026；P>0.05)。三种方式测量的IOP与Ks及Kf的相关性均无统计学意义(r＝0.158，0.158；P>0.05)。通过Bland-Altman以及95%LoA分析显示两者的95%LoA为±5.2 mmHg。年龄和IOP之间无明显的线性趋势。 结论CanonTX20测量的IOP值和VX120测量的IOP值一致性较差，说明不可相互替代；CCT与CanonTX20及VX120测量的IOP值均存在相关性，但CCT与校正后的VX120测量的IOP值无相关性；Ks和Kf与IOP值均无相关性。     

Estimation of Intraocular Lens Power Calculation after Myopic Corneal Refractive Surgery: Using Corneal Height in Anterior Segment Optical Coherence Tomography

PurposeTo investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery.MethodsThis study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subsequent successful cataract surgery. The CH was measured with AS-OCT, and the measured ELP (ELP_m) was calculated. Intraocular lens power, which could achieve actual emmetropia (P_real), was determined with medical records. Estimated ELP (ELP_est) was back-calculated using P_real, axial length, and keratometric value through the SRK/T formula. After searching the best-fit regression formula between ELP_m and ELP_est, converted ELP and intraocular lens power (ELP_conv, P_conv) were obtained and then compared to ELP_est and P_real, respectively. The proportion of eyes within a defined error was investigated.ResultsMean CH, ELP_est, and ELP_m were 3.71 ± 0.23, 7.74 ± 1.09, 5.78 ± 0.26 mm, respectively. The ELP_m and ELP_est were linearly correlated (ELP_est = 1.841 × ELP_m - 2.018, p = 0.023, R = 0.410) and ELP_conv and P_conv agreed well with ELP_est and P_real, respectively. Eyes within ±0.5, ±1.0, ±1.5, and ±2.0 diopters of the calculated P_conv, were 23.3%, 66.6%, 83.3%, and 100.0%, respectively.ConclusionsIntraocular lens power calculation using CH measured with AS-OCT shows comparable accuracy to several conventional methods in eyes following corneal refractive surgery.     

白内障患者角膜后表面散光的分布研究

目的：研究白内障人群角膜后表面散光的分布规律。方法分析2013年1月～2013年12月本院收治的白内障患者（94眼）Pentacam角膜地形图仪检查结果，总结角膜后表面散光的特点。结果（1）角膜后表面散光度数平均为（0.34±0.21）D。（2）角膜后表面散光的轴位平均（88.32°±23.10°）。（3）角膜后表面散光度数与前表面散光度数呈显著正相关（r=0.224，P＜0.05），角膜后表面散光轴位亦与前表面轴位呈显著正相关（r=0.255，P＜0.05）。结论角膜后表面散光度数很小，为顺规散光，其大小、轴位都与前表面呈正相关，即角膜后表面散光的大小和轴位都与前表面有一定的“吻合性”或“靠拢性”。     

Clinical and biochemical markers in CIPN: A reappraisal

The increased survival of cancer patients has raised growing public health concern on associated long-term consequences of antineoplastic treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is a primarily sensory polyneuropathy, which may be accompanied by pain, autonomic disturbances, and motor deficit. About 70% of treated cancer patients might develop CIPN during or after the completion of chemotherapy, and in most of them such complication persists after six months from the treatment. The definition of the potential risk of development and resolution of CIPN according to a clinical and biochemical profile would be certainly fundamental to tailor chemotherapy regimen and dosage on individual susceptibility. In recent years, patient-reported and clinician-related tools along with quality of life instruments have been featured as primary outcomes in clinical setting and randomized trials. New studies on metabolomics markers are further pursuing accurate and easily accessible indicators of peripheral nerve damage. The aim of this review is to outline the strengths and pitfalls of current knowledge on CIPN, and to provide a framework for future potential developments of standardized protocols involving clinical and biochemical markers for CIPN assessment and monitoring.     

Candida parapsilosis corneal graft infection from a single eye center: Histopathologic report of 2 cases

Fungal keratitis accounts for 6–53% of all cases of ulcerative keratitis in variable studies. The majority of cases are due to septate fungi. The abnormal cornea in cases of dry eye syndrome, chronic ulceration, erythema multiform and possibly HIV infection is infected more commonly with Candida, most commonly Candida albicans. Candida parapsilosis affects neonates and intensive care unit (ICU) patients and it has been recently found with increasing frequency. In a previous study on mycotic keratitis in our tertiary eye hospital, filamentous fungi were more commonly isolated than yeasts. We are presenting 2 successive cases of corneal graft infection by Candida parapsilosis referred to us from another eye center to attract the attention of ophthalmologists and health workers to such an infection.