Concentration of timolol in aqueous humour

Two groups of twenty patients who were to undergo a routine e.c.c.e. applied eye-drops containing timolol 0.1% or 0.5% twice daily during the week preceding their operation. A third group of twenty patients, using placebo drops, served as control. During the cataract surgery a sample of aqueous was collected. The samples from the timolol 0.1% patient group contained a significantly lower concentration of timolol than those from the timolol 0.5% patient group, but there was considerable overlap.     

Endophthalmitis: Current Approaches

Seventy patients referred with a diagnosis of endophthalmitis underwent anterior chamber and vitreous taps with intracameral antibiotic injections. Fifty-four eyes were culture positive, 34 (63%) after previous intraocular surgery, 12 (22%) had sustained penetrating trauma, and 8 (15%) resulted from a metastatic infection. Of 61 total isolates, 48 (79%) were gram positive, 9 (15%) were gram negative, and 5 (8%) were fungi. Visual recovery after surgery was related to the relative virulence of the organisms isolated. Twenty-four (44%) eyes achieved 20/400 or better vision, but only seven (13%) obtained 20/40 or better vision. Patients with a markedly abnormal ERG operatively demonstrated poor visual acuity recovery, while patients with near normal ERG recovered better vision. The authors currently recommend vitrectomy in patients with endophthalmitis whenever the retina cannot be visualized.     

眼动记录技术在眼科的临床应用

眼动记录技术作为检测眼球运动的一种重要手段，其对细微眼球运动的捕捉能力使人类对眼球运动的观察发生了质的飞跃。该技术的发展使人们对眼球运动障碍类疾病如斜视、眼球震颤、颅神经麻痹、颅脑损伤等的认识不断深入，为阐明其发病机制提供了途径。同时，其精确度的提高已能满足临床使用需求，广泛应用于临床各学科中，促进了相关临床诊疗技术的进步。目前在眼科主要应用于先天性眼球震颤手术疗效评估，青光眼患者视野检查及提高LASIK手术精确度等。就几种主要的眼动记录技术进行介绍，并对其在眼科的临床应用情况及前景等进行综述。     

Topical vs Subconjunctival Treatment of Bacterial Corneal Ulcers

The efficacy of eye drops and subconjunctival injections in the treatment of bacterial corneal ulcers for each of the following combinations were compared: cefazolin for staphylococcal ulcers, gentamicin for staphylococcal ulcers, and gentamicin for pseudomonal ulcers. Topical and subconjunctival therapy were equally effective in reducing the numbers of viable bacteria in experimental corneal ulcers. Subconjunctival injections produced high but transient peaks followed by persistent low troughs. In contrast, eye drops produced moderate but sustained concentrations throughout the treatment period. Under the conditions of this study, it appears that transient high peaks are not needed to eliminate bacteria effectively from a corneal ulcer. Since eye drops and subconjunctival injections are equally effective, other factors should determine the preferred route or routes of therapy.     

Applications of the polymerase chain reaction in clinical ophthalmology

Molecular biology has become a valuable component in many areas of medicine, including ophthalmology. Polymerase chain reaction (PCR) is the most widely used tool. It has proven to be a powerful technique in diagnosis and quantification of microorganisms and antibiotic resistance screening. For a growing number of ophthalmic conditions PCR testing can be conducted. It is therefore important that clinicians be knowledgeable about the indications, strengths, and limitations of the technique. The purpose of this review is to explore the current role of PCR in the diagnosis and management of eye disease.     

Management of Intraocular Infections in HIV

ABSTRACT

Purpose: Overview of treatment options for the most common intraocular opportunistic infections in patients with acquired immunodeficiency syndrome (AIDS), including ocular syphilis, ocular tuberculosis, toxoplasmic chorioretinitis, and viral retinitis.

Method: Narrative Review.

Results: Despite the huge advances in the development of combined antiretroviral therapy (cART) for the management of patients with human immunodeficiency virus (HIV) infection, opportunistic infections still represent a significant diagnostic dilemma and cause of ocular morbidity in patients with HIV.

Conclusion: Although the treatment of intraocular infections in patients with AIDS may be challenging, prompt assessment of the clinical features and appropriate aggressive management of the underlying etiology are critical to avoid life and vision threatening.     

Bevacizumab: off-label use in ophthalmology

Bevacizumab is a full-length, humanized monoclonal antibody directed against all the biologically active isoforms of vascular endothelial growth factor (VEGF-A). The antibody was initially designed and studied as an anti-angiogenic strategy to treat a variety of solid tumors. After approval by the US Food and Drug Administration, bevacizumab gained access into ophthalmology to treat various types of neovascular diseases. Since the first report in 2005 more than 100 publications share the experience with bevacizumab in ophthalmology. Two authors independently assessed the research results from Pubmed to April 2007. The reference list is a selection of key publications related to the issue. Currently, there is no well-designed randomized controlled trial yet to establish the efficacy and safety of intraocular bevacizumab for any ocular disease in spite of its assumed characteristics representing the most cost-effective VEGF inhibitor.     

玻璃体内注射庆大霉素致视网膜损伤的实验研究Ⅰ．组织病理学观察

为探讨庆大霉素对视网膜的毒性作用和评估玻璃体内注射庆大霉素的安全剂量，采用眼底镜观察及光镜、电镜技术对注射５种不同剂量庆大霉素的青紫蓝兔视网膜标本进行观察。结果：３０００μｇ庆大霉素注射后眼底表现为视盘水肿，后极部视网膜大片坏死，镜下视网膜组织形态严重破坏；５０～５００μｇ剂量注射引起后极部视网膜色素改变，组织损伤早期局限在视网膜内层，晚期全层受累。提示庆大霉素对视网膜的损伤程度随注入剂量增加而加重，即使５０μｇ的微小剂量仍可产生视网膜损伤。     

Ultrastructural studies of cornea, iris and lens in a case of siderosis bulbi

Transmission electron microscopy studies of cornea, iris and lens from a case of ocular siderosis due to a retained intraocular foreign body (IOFB) and vitreous hemorrhage are presented. We observed widespread degeneration of lens epithelium, iris stromal cells and iris pigment epithelium associated with intra- and extracellular siderosomes. A direct relationship was found between the degree of cell degeneration and the number of intracellular siderosomes in lens epithelium. This is contrary to findings in other siderotic tissues which show intracellular iron deposition to be associated with increased ability to detoxify iron. The cornea showed siderosomes only within keratocytes, and there was no evidence of a relationship between siderosome accumulation and cell degeneration. The literature on ultrastructural studies of ocular siderosis is reviewed and the current theory of the mechanism of chronic iron toxicity is discussed.     

Avastin在眼科应用的研究进展

Avastin是第一个被美国FDA批准的通过抑制血管生成发挥抗癌作用的新药,是现行几种抗血管生成制剂之一,可抑制血管内皮生长因子(VEGF)的生成,近年研究表明,该药在治疗眼部新生血管性以及渗出性病变中疗效显著,而且价格便宜,应用前景十分广阔。     

The amniotic membrane in ophthalmology

The amniotic membrane is the innermost of the three layers forming the fetal membranes. It was first used in 1910 in skin transplantation. Thereafter it has been used in surgical procedures related to the genito-urinary tract, skin, brain, and head and neck, among others. The first documented ophthalmological application was in the 1940s when it was used in the treatment of ocular burns. Following initial reports, its use in ocular surgery abated until recently when it was re-discovered in the Soviet Union and South America. Its introduction to North America in the early 1990s heralded a massive surge in the ophthalmic applications of this membrane. The reintroduction of amniotic membrane in ophthalmic surgery holds great promise; however, although it has been shown to be a useful and viable alternative for some conditions, it is currently being used far in excess of its true useful potential. In many clinical situations it offers an alternative to existing management options without any distinct advantage over the others. Further studies will undoubtedly reveal the true potential of the membrane, its mechanism(s) of action, and the effective use of this tissue in ophthalmology.     

Hysterical symptoms in ophthalmology

Ophthalmologic symptoms are often not sufficiently accounted for by organic pathology. The complaints of these patients have been labeled hysterical, psychogenic, non-organic, or functional. The psychiatric nosology in this area may be the most confusing in the whole field of clinical medicine. The Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) offers a classification designed to reduce non-empirical concepts and ideology to a minimum. On this background, we discuss the hysterical symptoms encountered in clinical ophthalmology with special emphasis on psychogenic amblyopia and blepharospasm. Motor symptoms are commonly not of psychogenic origin. It is suggested that ophthalmologists are most likely to treat patients with psychogenic symptoms, using suggestion, patience, and reassurance. Few patients require psychiatric consultation and a specific psychiatric therapy. The association of hysteria with organic brain disease and the issue of symptom lateralization are briefly discussed. Eventually, we reject the psychoanalytic approach and suggest that the concept of abnormal illness behavior and the neurobiological models involving corticofugal inhibition, primitive reflex mechanisms, and an attention disturbance, serve best to understand the nature of the phenomenon hysteria.     

Prophylactic antibiotics for ophthalmic surgery

Preoperative or immediately postoperative antibiotics have been used by ophthalmic surgeons routinely as prophylaxis for postoperative endophthalmitis. The rationale for such prophylaxis, and the evidence which supports its efficacy are well founded. The optimal choice of antibiotics, however, from the standpoints of efficacy, delivery (route, dosage, and frequency of administration), adverse reactions, and cost is far less well established. This review considers these issues in the context of a critical evaluation of the pertinent literature.     

Sigma受体在眼科领域的研究进展

Sigma受体(sigma receptor,Sig R)是新发现的非吗啡类的独立受体,它参与保护神经、影响细胞活性和增殖、调节离子通道等重要生物学功能。Sig R在眼组织中包括在泪腺、晶状体、虹膜-睫状体和视网膜上都有表达,其配体在眼科领域也存在着广泛的作用。本文对Sig R的生物学特征及其在眼科的研究进展作一综述。     

玻璃体内注射庆大霉素对家兔视网膜和视神经影响的实验研究

通过眼电生理和光电镜方法研究了庆大霉素玻璃体内注射对家兔视网膜和视神经的影响。其主要结果下：１，视网膜电图和视诱发电位在监测药物引起眼毒性方面有一定价值。２，庆大霉素引起视网膜和视神经中毒时，组织学性电生理检查结果是一致的。３，庆大霉素引起家兔视网膜和视神经的毒性剂量最低为０．２ｍｇ。４，庆大霉素的损害机理是干扰了溶酶体酶活性，使细胞功能紊乱。     

球内异物74例手术疗效分析

目的:分析不同的手术方法治疗眼球开放性外伤后球内异物的手术效果。方法:对74例(均为单眼受伤)开放性眼外伤合并球内异物的临床资料进行回顾性分析。结果:手术取出异物后保住眼球71眼（96%）,未保住眼球3眼（4%）。成功的71例,均完整取出异物。其中42例并发外伤性白内障(42/74,57%),18例并发玻璃体积血(18/74,24%),2例并发视网膜脱离(2/74,3%),9例继发性青光眼(9/74,12%)。其中44眼行巩膜外路电磁铁吸出异物,30眼采用玻璃体切除术取出异物。失败3例（3/74,4%）皆未完整取出异物,术后合并真菌性眼内炎而行眼球摘除术。结论:对于合并有晶状体、玻璃体混浊的眼内异物、后极部异物需行玻璃体切除术,赤道前、定位准确的磁性异物,以巩膜外路磁吸术为宜。而最终能否保住眼球和手术是否完整取出异物有一定关联。     

Intraocular pressure,ocular toxicity and neurotoxicity after administration of Δ9-Tetrahydrocannabinol or cannabichromene

Δ-9-Tetrahydrocannabinol (Δ⁹-THC) or cannabichromene, a structurally diverse naturally occurring cannabinoid, was delivered unilaterally to the corneas of cats either acutely by application of single drops or chronically via osmotic minipumps over a period of nine days. While Δ⁹-THC only reduced intraocular pressure (IOP) minimally after acute administration, this cannabinoid produced substantial reductions in ocular tension during the entire period of chronic administration. Ocular toxicity during chronic treatment, however, was pronounced; conjunctival chemosis, erythema, and hyperemia were sustained, and corneal opacities approximating the site of drug delivery became evident within three to five days. In contrast, cannabichromene did not significantly alter IOP either acutely or during the nine days of chronic administration, and ocular toxicity was not apparent.After systemic administration of Δ⁹-THC to rats, a dose-related increase in the appearance of 8–13 Hz polyspike discharges became evident in the electrocorticogram during wakefulness and behavioral depression. These polyspikes subsequently reappeared during rapid eye movement (REM) sleep episodes. Cannabichromene was devoid of this effect.These results indicate that, in contrast with acute administration, chronic delivery of Δ⁹-THC to cat eyes produces substantial reductions in IOP. The tension lowering effect, however, is accompanied by considerable ocular toxicity and neurotoxicity. As cannabichromene lacked these activities, the terpenoid portion of the cannabinoid structure appears to be important for their mediation.