原发性开角型青光眼的早期诊断

青光眼是进行性视网膜神经节细胞(retinal ganglion cells,RGCs)丢失引起视神经乳头及视野特征性改变的一组疾病,最终将导致不可逆视功能损害。早期诊断是疾病早期治疗使进行性视功能损害停止或延缓的关键。近年来出现的视神经结构检查及视神经功能检查方法与传统视野检查相比,可提高原发性开角型青光眼(primary openangle glaucoma,POAG)的早期诊断率。不同检查的联合应用可提高诊断的敏感性,在临床应用中可以根据敏感度及特异度的要求来选择相应的结构或功能检查方法。     

Correlation of the vision-related functional impairment associated with blepharoptosis and the impact of blepharoptosis surgery.

OBJECTIVE: To assess the effect of blepharoptosis on patients' visual function and health-related quality of life and to determine what measures are associated with postsurgical change in functional status. DESIGN: Prospective, observational case series. PARTICIPANTS: One hundred patients with unilateral or bilateral blepharoptosis. INTERVENTION/MAIN OUTCOME MEASURES: Preoperative and postoperative upper eyelid position (i.e., margin reflex distance [MRD]) and superior visual field (SVF) height, as well as subjective visual function and health-related quality-of-life functional status before and after ptosis surgery. RESULTS: There was a mean 30-point increase in functional index score after ptosis repair (P < 0.001). Lower (more ptotic) preoperative upper eyelid position and SVF (combined eye) were associated with greater change in functional index after surgery (r = -0.290, P = 0.007 and r = -0.39, P = 0.003, respectively). Preoperative visual field testing with manual lid elevation was not significantly correlated to the postoperative change in functional index (P > 0.100). The strongest correlation of postoperative functional index change was with the preoperative functional status (r = -0.79, P < 0.001). CONCLUSIONS: Patients' functional status is reduced by blepharoptosis, and surgical repair results in measurable increase in health-related quality of life. Patients' self-reported preoperative functional impairment is most strongly associated with the degree of postsurgical functional improvement.     

Bilateral Concurrent Eye Examination with a Head-Mounted Perimeter for Diagnosing Functional Visual Loss

The authors here report a case series where bilateral concurrent eye examination, using a head-mounted perimeter (imo®), was employed to facilitate diagnosis of functional visual loss, as regular ophthalmological tests were ineffective. Subjects (11-year-old female, 15-year-old male, and 24-year-old male) were diagnosed with unilateral functional visual loss by using the imo®, at the Kitasato University hospital. The results of the imo® and those of Goldmann perimetry or Humphrey Field Analyzer II differed for all subjects, which is indicative of potential functional visual loss. Bilateral concurrent examination with the imo® may become a standard for future diagnosis of unilateral functional visual loss.     

fMRI retinotopic mapping at 3 T: benefits gained from correcting the spatial distortions due to static field inhomogeneity

fMRI retinotopic mapping usually relies upon Fourier analysis of functional responses to periodic visual stimuli that encode eccentricity or polar angle in the visual field. Generally, phase estimations are assigned to a surface model of the cerebral cortex and borders between retinotopic areas are eventually determined following ad hoc phase analysis on the surface model. Assigning functional responses to a surface model of the cortex is particularly sensitive to geometric distortions of the 3D functional data due to static field inhomogeneity. Here, we assess and document the benefits gained from correcting the fMRI data for these effects, under standard experimental conditions (echo-planar imaging, 3.0-T field strength) and with well-chosen acquisition parameters (regarding slice orientation and phase-encoding direction). While it appears that, in the absence of correction, errors in the estimates of the borders between low-order visual areas do not then significantly exceed the variance of statistical origin, about half of the functional responses in a retinotopic experiment are misassigned to neighboring functional areas. Therefore, correction of the effects due to geometric distortions is important in any retinotopic mapping experiment and by extension in any fMRI experiment on the visual system.     

Functional visual loss

Functional visual loss is a common problem encountered in practice. It must be recognized that this problem occurs in patients who have organic illness. Manual perimetry is the most effective method for evaluating functional visual loss, and the presence of a central scotoma in a functional visual field strongly suggests that organic pathology is present.Neuropsychological and psychiatric intervention can be useful in treating these patients.     

Characterization of functional changes in macular holes and cysts.

Precise characterization of functional loss in small retinal lesions is difficult with conventional techniques. Using the scanning laser ophthalmoscope, the authors evaluated functional changes and fixation behavior in 26 eyes with macular holes and 15 eyes with macular cysts. A dense scotoma was present over all macular holes; 24 had no detectable functional alteration at the margins of the hole, and fixation was above the horizontal meridian in all eyes. Nine eyes with cysts had no detectable functional loss over the cyst. Only two eyes had small areas of dense scotoma within the cyst area, and four had areas of relative scotoma. Fixation was central in all eyes. Characterization of functional changes is helpful in differentiating holes from cysts. Photocoagulation at the margin of the holes may result in further functional damage.     

Functional vision with cataracts of different morphologies: comparative study

PURPOSE: To evaluate the influence of cataract morphology on the functional vision of patients with age-related cataract and normal macular function and compare subjectively perceived functional impairments to distance visual acuity, reading acuity, and maximum reading speed between cataract types. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Seventy-five patients awaiting first-eye cataract surgery were asked to characterize their visual difficulties in everyday life using a German version of the VF-14 questionnaire. Cataracts were categorized and graded using the Lens Opacities Classification System III. Monocular and binocular visual acuity and reading performance were determined in randomized order. RESULTS: There were significant differences in functional vision between nuclear cataracts and posterior subcapsular cataracts (PSC); the VF-14 score and the self-reported visual satisfaction were significantly lower in PSC patients (P<.05). Posterior subcapsular cataracts significantly increased self-reported impairment in distance and near vision, although the visual acuity was comparable to that in the other groups (P =.9). Significant differences in functional vision were also seen between PSC and nuclear-cortical cataracts (P<.05). No significant differences in functional vision were found between nuclear cataracts and nuclear-cortical cataracts (P>.05). CONCLUSIONS: The VF-14 questionnaire reliably evaluated functional differences caused by different cataract morphologies; these differences were underestimated when only visual acuity was measured. Patients with PSC had increased functional impairment, indicating that cataract surgical intervention is indicated at an earlier stage in these patients. The significant differences between the morphological types of cataract should be taken into consideration when the benefit of cataract surgery is to be measured on the basis of functional improvement.     

斜视患者脑功能与结构异常的研究进展

斜视是一种常见的眼球运动障碍,表现为眼位偏斜,常伴双眼视觉功能受损。正常眼位有赖于参与视觉系统和眼球运动系统的各脑区的正常功能和它们之间的协调配合,其中任一层次的受损都可能引起斜视。早期神经电生理和免疫自显影技术应用于动物实验,发现初级视觉皮层功能损伤,包括双眼视神经元减少、眼优势柱代谢改变。近年来,功能磁共振的发展促进了对人脑皮层功能变化的认识。研究发现斜视患者不仅存在与眼球运动及双眼视觉功能障碍相关的脑皮层及皮层间联系的损伤,还存在与代偿相关的可塑性改变。而基于体素的形态计量学和弥散张量成像技术的应用为斜视患者大脑异常提供了解剖学依据。本文从脑功能与结构异常角度对近几年有关斜视神经机制的研究进展进行综述,以期为进一步研究提供参考。     

The ocular surface and tear film and their dysfunction in dry eye disease

The ocular surface, tear film, lacrimal glands, and eyelids act as a functional unit to preserve the quality of the refractive surface of the eye and to resist injury and protect the eye against changing bodily and environmental conditions. Events that disturb the homeostasis of this functional unit can result in a vicious cycle of ocular surface disease. The tear film is the most dynamic structure of the functional unit, and its production and turnover is essential to maintaining the health of the ocular surface. Classically, the tear film is reported to be composed of three layers: the mucin, aqueous, and lipid layers. The boundaries and real thickness of such layers is still under discussion. A dysfunction of any of these layers can result in dry eye disease.     

Respondent impact on functional ability outcome measures in vision rehabilitation.

PURPOSE: To assess the relative importance of several measurement facets including respondent (patient or clinicians), item (functional domains), and administration (pre- and postrehabilitation) on assessing perceived functional outcomes in vision rehabilitation. METHODS: A convenience sample of VA veterans were assessed with a self-report and clinician rated perceived functional ability instrument before and after rehabilitation services. The items were analyzed using a Rasch model to ensure that both versions fit the restrictive model well enough to be directly compared. A second analysis using a generalizability theory model assessed the relative importance of each measurement facet. RESULTS: The Rasch model supported the equivalence of the two different versions of the outcome instrument. The generalizability theory model showed that administration accounted for the majority of the variance and that respondents and items contributed very little to perceived functional assessment. CONCLUSIONS: The results support the conclusion that both clinical ratings and patient self-reported perceived functional ability ratings provide relative equivalent values in blind and low-vision rehabilitation settings. The relative importance of administration time in predicting scores may support the general conclusion that rehabilitation produces the largest relative changes in perceived functional ability and ought to shift researchers' focus away from the subtleties of instrument development and more toward assessing program and individual outcomes. Finally, these findings suggest that there is little promise in modeling individual differences to account for perceived functional ability changes because of rehabilitation.     

Modulatory and inhibitory processes in the visual cortex

The functional role of three putative neurotransmitter systems in the visual cortex is compared; the GABAergic inhibitory interneurons, the interneurones containing somatostatin and the cholinergic input originating from the nucleus basalis of Meynert (nbM). Evidence is presented to support the role of GABAergic processes in the generation of the functional structure of the visual cortex and the view that the cholinergic input exerts a neuromodulatory influence enhancing stimulus selective responses. Although the neuropeptide somatostatin produces facilitatory and inhibitory effects on visual cortical cells there is no clear functional pattern to its action. The possible significance of this data and the interaction of SSt with GABA is discussed in the light of evidence that they may coexist in some cells.     

Contrast sensitivity and measuring cataract outcomes

Clinical research has demonstrated the the continuous decline of the contrast sensitivity with age results from increasing spherical aberration of the human crystalline lens. Replacing the crystalline lens with appropriate modeled pseudophakic lens can provide superior contrast sensitivity and functional vision. As advances in the technology allow cataract and refractive surgeons to address higher-order optical aberrations, the measurement of functional vision becomes increasingly critical as a gauge of the progress. Contrast sensitivity testing is assuming a prominent place in the evaluation of surgical modalities because it reflects functional vision, correlates with visual performance, and provide a key to understanding optical and visual processing of images.     

Risk of dry eye after mullerectomy via the posterior conjunctival approach for thyroid-related upper eyelid retraction

INTRODUCTION : Mullerectomy by a conjunctival approach is an excellent way to reduce thyroid-related superior lid retraction. Especially the lateral horn of the levator, into the lacrimal gland, has to be reduced. Alterations in lacrimal secretion have been hypothesized, but never studied. MATERIALS AND METHODS : The basal and reflex Schirmer test and functional status were studied in 39 patients with thyroid-related orbitopathy after mullerectomy by a conjunctival approach (12 functional, 27 cosmetic indications). In 24 patients, the results could be compared with those of other measures carried out pre- or postoperatively or, in case of unilateral surgery, the operated and non-operated sides were compared. RESULTS : The Schirmer test was reduced in 7 of 12 functional cases and in 4 of 27 cosmetic cases. Although tear production was reduced, only two patients had to have increased dosages of artificial tears and two other patients required punctum plugs. Among the 12 functional indications, 10 showed an improved corneal surface. CONCLUSION : Lacrimal production may be reduced after mullerectomy by the conjunctival approach. Nevertheless, the clinical risk is low in comparison with the functional and cosmetic results of the procedure. At present, we try to identify and preserve the lacrimal ostia during surgery.     

Repair of acute common canalicular avulsion by angular vein grafting

Traumatic avulsion of the common canaliculus was repaired in one patient by using a segment of the angular vein as an autograft. The vein graft served as a functional anastomosis between the lacrimal sac and both upper and lower canaliculi. The technique is a viable alternative for functional repair of the acutely lacerated lacrimal drainage system in which canalicular tissue is missing.     

高度近视合并青光眼的临床诊断研究进展

众多研究表明高度近视是青光眼性视神经病变的高危因素。然而,由于高度近视本身会引起视网膜和视神经纤维层损伤,所以青光眼相关的结构和功能改变可能会被高度近视掩盖。为了在高度近视患者中早期识别出青光眼性改变,减少漏诊或误诊的可能性,深入了解高度近视合并青光眼的临床特征是非常必要的。本文概括了经典的结构和功能检查在诊断高度近视合并青光眼中的作用以及存在的困难,并针对这一诊断难题提供一些可能的解决措施。     

静息态功能磁共振成像在青光眼疾病中的应用研究进展

青光眼是全球第一大不可逆致盲性眼病,是一组以特征性视神经损伤和视野缺损为共同特征的神经眼科疾病。已有多项研究表明,青光眼的损害不仅局限于眼球局部视神经节细胞的凋亡,而且会累及大脑视皮层整个视觉通路,是一种全脑神经退行性疾病。近年来,功能性磁共振成像(functional magnetic resonance imaging,fMRI)技术飞速发展,将神经系统的解剖和功能相结合,使局部脑组织的损伤与脑功能的缺失对应起来,可以实现在无创条件下观察中枢神经系统解剖结构及功能变化,为青光眼病理机制的研究提供了有效证据。而静息态功能磁共振成像(resting-state functional magnetic resonance imaging, rs-fMRI)作为神经影像学的热点研究技术,为探讨青光眼患者视觉相关脑区的解剖结构、代谢以及功能改变提供了影像学支持。本综述主要讨论了rs-fMRI的基本原理以及低频振幅(amplitude of low-frequency fluctuation, ALFF)、局部一致性(regional homogeneity, ReHo)、度中心度(degree centrality, DC)、功能连接(functional connectivity, FC)等几种较为常用的分析方法在青光眼中应用的研究进展。     

Diabetic retrobulbar optic neuropathy

The authors describe a case of retrobulbar optic neuropathy in a patient with type 1 Diabetes mellitus. In spite of good metabolic control, there has been a slow but progressive functional visual decline. Worthy of note is the abnormal precocity of the appearance of the functional damage of the optic nerve compared to the involvement of the peripheral system.     

Die Rolle des retinalen Pigmentepithels im Rahmen visueller Funktionen

The evolution of light sensitive cells probably began with a primitive functional unit composed of a photoreceptor cell and a pigmented cell. Even during embryonic development this functional unit is formed in a differentiation process in which the two interacting partners depend on each other. For some of the most important forms of retinal degeneration this knowledge on the functional cooperation between retinal pigment epithelium and photoreceptors is of great importance for analysis and development of therapeutic approaches. In this way mutations of genes which are expressed in photoreceptors can lead to diseases which start in the retinal pigment epithelium and vice versa. This article summarizes the variety of different functions of the retinal pigment epithelium and describes the failure of those functions which are of most clinical importance.     

Intraocular listeriosis

Listeria monocytogenes endophthalmitis is an uncommon localization. Its evolution is usually complicated by disabling functional visual loss. We report a case occurring in a peculiar epidemiological context. Early diagnosis by paracentesis allowed consequent antibiotic therapy. The evolution has been dramatically favorable. Early treatment allowed an excellent functional recovery when compared to the reported cases of the literature.     

SARS-CoV S蛋白功能性受体ACE2在人角膜、结膜中的表达

目的 检测人角膜、结膜中血管紧张素转化酶2(ACE 2)的表达,由此来初步推断重症急性呼吸综合征(SARS)冠状病毒由眼部入侵的可能。 方法 取成人眼球破裂伤摘除的眼角膜和结膜组织及4~6个月中期引产胎儿的眼角膜、结膜、心、肺组织,分别采用RT-PCR和免疫组化方法检测组织中ACE 2的表达。取成人尸体解剖的心、肺组织作为对照。 结果 在上述各种组织中均检测到了ACE 2的表达。 结论 眼角膜、结膜是人体暴露于SARS冠状病毒的一个重要部位,研究结果从mRNA和蛋白质水平证实了眼部组织存在SARS冠状病毒S蛋白的功能性受体ACE 2,由此初步推断SARS-CoV存在由眼部入侵的可能,为临床进一步研究SARS的防护和致病机制提供了线索。