A scoping review of patients' barriers to eye care for glaucoma and keratitis

In this scoping review, we examine underlying causes of loss to follow-up for chronic (glaucoma) and acute (corneal ulcers) eye conditions using the Penchansky and Thomas access to care framework. We explore barriers by World Health Organization income levels and by studying geographical location. We identified 6,363 abstracts, with 75 articles retrieved and 16 meeting inclusion criteria. One article discussed barriers to follow-up care for people with corneal ulcers, and the other 15 were for people with glaucoma. The most frequent barriers to care were affordability, awareness, and accessibility. The international studies had a greater percentage of studies report acceptability as a barrier to loss to follow-up. Countries with universal healthcare included affordability as a loss to follow-up barrier, emphasizing that cost goes beyond the ability to pay for direct treatment costs. Understanding and addressing barriers to follow-up care can aid the goal of continued care and decrease the risk of poor outcomes and vision loss.     

Mirtazapine-induced acute angle closure

Acute angle closure (AAC) is an ocular emergency with symptoms including blurred vision, eye pain, headache, nausea, vomiting and reddening of the eye those results from increased intraocular pressure. This clinical condition can lead to permanent damage in vision, thus causing blindness by generating progressive and irreversible optic neuropathy if left untreated. There are several reasons of AAC, including several types of local and systemic medications; mainly sympathomimetics, cholinergics, anti-cholinergics, mydriatics, anti-histamines, antiepileptics like topiramate, tricyclic and tetracyclic antidepressants, serotonin reuptake inhibitors, antipsychotics, sulfa-based drugs and anticoagulants. Mirtazapine, a noradrenergic and specific serotonergic antidepressant, is an atypical antidepressant with a complex pharmacological profile. This case report describes a patient with major depressive disorder, who experienced AAC after the first dosage of mirtazapine treatment, and highlights the importance of close monitoring of individuals under antidepressant treatment particularly immediately after initiation of the drug.     

原发性青光眼患者双侧视放射及视皮质的磁化传递成像

目的 应用磁化传递成像(MTI)研究原发性青光眼患者双侧视放射、视皮质的异常,探讨青光眼性损伤对后视路的影响.方法 选取20例常规颅脑MR检查无异常的原发性青光眼患者(青光眼组)及31名正常志愿者(对照组)行MTI检查,采用扰相梯度回波序列(SPGR)成像,分别于施加磁化传递饱和脉冲前后进行扫描.将扫描图像进行后处理分析,测量双侧视放射及视皮质的磁化传递率(MTR).组间各部位MTR值的比较采用两样本t检验(方差不齐则采用Satterthwaite近似t检验).结果 青光眼组左、右两侧视放射的MTR值分别为(32.8±2.2)％、(32.7±2.0)％,对照组相应部位MTR值分别为(34.6±1.4)％、(34.8±1.3)％,青光眼组低于对照组,差异有统计学意义(左侧t=3.284,右侧t=4.040;P值均＜0.01).青光眼组左、右两侧视皮质的MTR值分别为(30.1±2.0)％、(30.8±1.8)％,对照组相应部位MTR值分别为(32.3±1.2)％、(32.4±1.2)％,青光眼组低于对照组,差异也有统计学意义(左侧t =4.319,右侧t=3.445;P值均＜0.01).结论 青光眼患者后视路发生了潜在神经病理学变化,提示青光眼是累及全视路的病变.MTI能在肉眼可见的影像学改变之前提供微观病理方面的信息,是活体人青光眼视觉通路跨突触损害研究的有用方法,也为青光眼临床诊治及评估预后提供了新的思路.     

原发性青光眼视神经扩散张量成像与视网膜神经纤维层厚度的相关性

目的 探讨原发性慢性闭角型青光眼视神经扩散张量成像(DTI)与视网膜神经纤维层(RNFL)厚度的相关性.资料与方法 25例原发性慢性闭角型青光眼患者(46只眼,病变组)和20例正常人(40只眼,对照组)分别行3.0TMR视神经DTI和美国OPTOVE公司RTVUE眼球光学相干断层扫描(OCT)检查,分析视神经部分各向异性(FA)值与RNFL厚度的相关性.结果 病变组视神经平均FA值为(0.248±0.083)×10-6 mm2/s,RNFL上方、下方、平均厚度分别为(82.28±20.06) μm、(84.18±18.18) μm、(83.14±18.09) μm;对照组平均FA值为(0.584±0.035)×10-6 mm2/s,RNFL上方、下方、平均厚度分别为( 110.72±12.08) μm、(109.54±10.08) μm、(102.86±11.32) μm.与对照组比较,病变组视神经FA值降低,RNFL厚度变薄,差异均有统计学意义(P＜0.05).视神经FA值与RNFL上方、下方、平均厚度均呈正相关(r=0.612、0.557、0.607,P＜0.05).结论 视神经FA值与RNFL厚度呈正相关,为提高青光眼视神经病理改变的认识和防治提供信息.     

Ahmed青光眼阀植入术后并发症分析及处理

目的探讨不同类型的青光眼采用Ahmed青光眼阀植入术后出现并发症的处理。方法分析23例(26只眼)Ahmed青光眼阀植入术失败的原因,并对其处理措施及疗效进行回顾性分析,术后随访36个月。结果23例(26只眼)Ahmed青光眼阀植入眼压由术前平均(31.84±7.10)mm Hg(8.01~47.03 mm Hg)。术后降至(19.86±7.10)mm Hg(8.01~31.03 mm Hg)。其早期并发症有浅前房、低眼压的9只眼,占34.62%;早期高眼压的7只眼,占26.92%;迟发性脉络膜上腔出血3只眼,占11.54%;因引流盘纤维包裹引起术后中远期高眼压19只眼,占73.08%;引流物蚀出或引流管暴露的4只眼,占15.38%;眶上神经痛1只眼,占3.85%;排异反应1只眼,占3.85%。结论青光眼房水引流管植入术后并发症是不容忽视的,应据情况及时处理。     

Incidence,efficacy and safety of YAG laser goniopuncture following nonpenetrating deep sclerectomy at a university hospital in Riyadh,Saudi Arabia

Purpose

Assessing the frequency and evaluating the efficacy and safety of Neodymium:Yttrium Aluminum Garnet (Nd:YAG) Laser goniopuncture (LGP) following nonpenetrating deep sclerectomy (NPDS).

Design

Retrospective cohort study.

Patients and methods

We retrospectively reviewed the outcome of 197 eyes of 153 patients with open angle glaucoma who underwent either NPDS or NPDS combined with cataract extraction between January 2005 and September 2010 at King Abdulaziz University Hospital (KAUH). Both demographic and clinical data were retrieved and analysed.

Results

Goniopuncture (GP) was needed in 48 (24.4%) of the eyes which had NPDS or NPDS with cataract extraction after a mean post operative interval of 9.78 (±11.16) months. The mean IOP had significantly decreased from 23.3 (±5.9) mmHg prior to Nd:YAG LGP procedure to 14.6 (±4.4) mmHg at the last post-procedure assessment. At the last follow-up; Nd:YAG LGP was successful in controlling IOP in 27 eyes (56.3%). Mean Nd:YAG LGP failure time was 6.04 (±5.80) months. Young age (<50 years) (p = 0.001); type of glaucoma (secondary versus primary open angle, p = 0.0258) and the use of drainage implant (p = 0.038) were the identified predicting factors for the need of Nd:YAG LGP. Complications following Nd:YAG LGP occurred in 5 eyes (iris touch to TDM (4.2%), Hyphema (2.1%), hypotony maculopathy (2.1%) and choroidal detachment (2.1%).

Conclusions

LGP is an efficient IOP lowering procedure after NPDS, when it is indicated. It is a simple and noninvasive procedure. However, certain precautions should be taken to avoid complications.     

Biomechanics of Schlemm's canal endothelium and intraocular pressure reduction

Ocular hypertension in glaucoma develops due to age-related cellular dysfunction in the conventional outflow tract, resulting in increased resistance to aqueous humor outflow. Two cell types, trabecular meshwork (TM) and Schlemm's canal (SC) endothelia, interact in the juxtacanalicular tissue (JCT) region of the conventional outflow tract to regulate outflow resistance. Unlike endothelial cells lining the systemic vasculature, endothelial cells lining the inner wall of SC support a transcellular pressure gradient in the basal to apical direction, thus acting to push the cells off their basal lamina. The resulting biomechanical strain in SC cells is quite large and is likely to be an important determinant of endothelial barrier function, outflow resistance and intraocular pressure. This review summarizes recent work demonstrating how biomechanical properties of SC cells impact glaucoma. SC cells are highly contractile, and such contraction greatly increases cell stiffness. Elevated cell stiffness in glaucoma may reduce the strain experienced by SC cells, decrease the propensity of SC cells to form pores, and thus impair the egress of aqueous humor from the eye. Furthermore, SC cells are sensitive to the stiffness of their local mechanical microenvironment, altering their own cell stiffness and modulating gene expression in response. Significantly, glaucomatous SC cells appear to be hyper-responsive to substrate stiffness. Thus, evidence suggests that targeting the material properties of SC cells will have therapeutic benefits for lowering intraocular pressure in glaucoma.