Protection against corneal hyperosmolarity with soft-contact-lens wear

Hyperosmotic tear stimulates human corneal nerve endings, activates ocular immune response, and elicits dry-eye symptoms. A soft contact lens (SCL) covers the cornea preventing it from experiencing direct tear evaporation and the resulting blink-periodic salinity increases. For the cornea to experience hyperosmolarity due to tear evaporation, salt must transport across the SCL to the post-lens tear film (PoLTF) bathing the cornea. Consequently, limited salt transport across a SCL potentially protects the ocular surface from hyperosmotic tear. In addition, despite lens-wear discomfort sharing common sensations to dry eye, no correlation is available between measured tear hyperosmolarity and SCL-wear discomfort. Lack of documentation is likely because clinical measurements of tear osmolarity during lens wear do not interrogate the tear osmolarity of the PoLTF that actually overlays the cornea. Rather, tear osmolarity is clinically measured in the tear meniscus. For the first time, we mathematically quantify tear osmolarity in the PoLTF and show that it differs significantly from the clinically measured tear-meniscus osmolarity. We show further that aqueous-deficient dry eye and evaporative dry eye both exacerbate the hyperosmolarity of the PoLTF. Nevertheless, depending on lens salt-transport properties (i.e., diffusivity, partition coefficient, and thickness), a SCL can indeed protect against corneal hyperosmolarity by reducing PoLTF salinity to below that of the ocular surface during no-lens wear. Importantly, PoLTF osmolarity for dry-eye patients can be reduced to that of normal eyes with no-lens wear provided that the lens exhibits a low lens-salt diffusivity. Infrequent blinking increases PoLTF osmolarity consistent with lens-wear discomfort. Judicious design of SCL material salt-transport properties can ameliorate corneal hyperosmolarity. Our results confirm the importance of PoLTF osmolarity during SCL wear and indicate a possible relation between PoLTF osmolarity and contact-lens discomfort.     

抗结核药物对泪膜功能的影响

<正>我国结核患者在2011年统计已达500万例,仅次于印度位居世界第二[1]。临床多见抗结核药物引起肝损害及过敏反应,对眼部的副反应关注较少[2]。笔者临床中发现部分结核患者在抗结核治疗早期可出现视物模糊、异物感、干涩及视物不持久等类似干眼的主诉,眼科常规检查未发现明显视神经病变,更多为眼表的改变。笔者观察抗结核药物对眼表的毒副反应,报道如下。1资料与方法1.1研究对象收集2012年1月—2014年10月     

Distal biceps rupture: Evaluation and management

Injury to the distal biceps occurs in certain high risk groups. Anatomical continuity of the lacertus fibrosus has bearing on the extent of retraction of the torn tendon stump. The objective of clinical and imaging evaluation is to discriminate between tendinosis, partial tear, acute complete tear and chronic complete tear. A complete tear of the distal biceps tendon can be diagnosed clinically with the Hook test. The traditional Hook test and the resisted Hook test are useful clinical tests. Though x-rays are routinely done, MRI remains the investigation of choice. Non-operative treatment has a role in selected patients with partial tear or patients with complete tear who have low functional demands. Operative treatment is the recommended treatment for complete tear of the distal biceps and is associated with good functional outcome and patient satisfaction.     

Charcot hindfoot deformity reconstruction using a hindfoot nail- surgical technique

Various techniques of reconstruction of deformed Charcot hindfoot using different internal fixation devices have been described in the literature. We present our surgical technique using specific principles that has resulted in improved outcomes to allow correction of deformity, obtain stability and allow progression to weightbearing in orthotic shoes. We describe our preoperative evaluation, planning and surgical timing. We also hope to share some technical pearls and details on the finer points to achieve a satisfactory correction and reduce the learning curve.     

Minimum clinically important difference of the health-related quality of life scales in adult spinal deformity calculated by latent class analysis: is it appropriate to use the same values for surgical and nonsurgical patients?

BACKGROUND CONTEXT

Health-related quality of life (HRQOL) parameters have been shown to be reliable and valid in patients with adult spinal deformity (ASD). Minimum clinically important difference (MCID) has become increasingly important to clinicians in evaluating patients with a threshold of improvement that is clinically relevant.