全身性遗传疾病对角膜移植排斥的影响

角膜移植为治疗角膜盲的主要手段，而角膜移植排斥则是决定角膜植片存活时间和病人术后视力的关键。角膜得益于其特殊的眼前节“免疫赦免”状态，使得角膜移植能够在众多器官移植中享有极低的排斥率，然而排斥反应发生的风险依然存在。当机体处于遗传物质异常的特殊状态时，宿主将通过宏观调控“免疫赦免”状态对植片的保护作用或受体对移植物排异产生的有害作用，延迟或促进角膜移植排斥反应的发生，进而影响移植物的存活时间和透明度。该文综述与角膜移植排斥相关的多种全身性遗传疾病，总结全身性遗传疾病对角膜移植排斥的影响，浅析其发生的病理生理学机制以及诊疗的特殊性。     

481例住院角膜病统计分析

本文统计分析１９８５－１９９０年间我院眼科４８１例（５６９只眼）住院角膜病患者的病种分布和致盲原因。调查结果表明，发病性别男多于女（２：１），发病年龄以２１－５０岁为多，５３．６％，最常见及致盲率高的为角膜炎症和外伤，其中病毒性角膜炎最多（３３．９％），细菌性角膜溃疡致盲率最高（４２．２％），角膜外伤居第二。分析表明，今后工作的重点是预防和治疗角膜炎症和外伤。     

糖尿病致盲的局部和全身因素分析

本文检查了705例(1409只眼)糖尿病患者,对眼局部致盲原因和与盲有关全身因素进行了分析。双眼盲77例,占10.9％,单眼盲139例,占19.7％。盲目眼的局部原因以DR居首位,其中玻璃体出血、牵拉性视网膜脱离及新生血管性青光眼为主要致盲眼疾。全身相关因素显示,尿蛋白、收缩压、性别及病程与盲目密切相关,血糖与盲亦相关。     

Vitamin a cost-effectiveness model

To assist in the selection of a preferable vitamin A deficiency control policy, a model has been developed to organize information on program costs and program-related effects. The model was designed to compare three approaches: (1) diet modification; (2) fortification of processed foods; and (3) periodic large doses. Health effects projected are rates of specific eye pathologies associated with vitamin A deficiency (xerophthalmia), and mortalities within age cohorts. Effectiveness is calculated as a function of coverage, biological efficacy, and incidence of vitamin A deficiency. The model was applied to data from the Province of West Java in Indonesia. The results of this application suggest that funding level considerations are an important factor in selecting a preferred control strategy. In addition to determining the relative resource requirements of alternative interventions aimed at reducing the morbidity and mortality effects of vitamin A deficiencies, the model, using marginal cost and marginal effectiveness information, can serve as a guide to the most efficient allocation of resources for each type of intervention.     

Physical fitness of blind and sighted children

Summary Twenty-seven children (age 7–17 years) with varying degrees of blindness but with no other known disorder were assessed for physical fitness. Twenty-seven randomly selected children with normal eyesight were also assessed. Maximum oxygen uptake ( ) was measured directly during a progressive exercise test on a treadmill. There was a significant and substantial reduction in in totally blind children (mean ± standard deviation 35.0±7.5 ml · min^–1 · kg^–1) compared with normal children (45.9±6.6 ml · min^–1 · kg^–1). Partially sighted children had a significant but smaller reduction in . Fitness assessed by a step-test was significantly reduced in the visually impaired children, and skin-fold thickness was also significantly greater in totally blind children.The level of habitual physical activity for each child, as assessed by a questionnaire, correlated with (r=0.53,p<0.0001). Blind children were significantly less active than normal children, and the difference between mean for blind and normal children became non-significant when their different activity levels were taken into account. It is concluded that totally blind children are less fit than other children at least partly because of their lower level of habitual activity.     

Restoration of visual orienting into a cortically blind hemifield by reversible deactivation of posterior parietal cortex or the superior colliculus

A contralateral hemineglect of the visual field can be induced by unilateral cooling deactivation of posterior middle suprasylvian (pMS) sulcal cortex of the posterior parietal region, and this neglect can be reversed by additional cooling deactivation of pMS cortex in the opposite hemisphere. The purpose of the present study was to test whether an enduring hemianopia induced by removal of all contiguous visual cortical areas of one hemisphere could be reversed by local cooling of pMS cortex in the opposite hemisphere. Two cats sustained large unilateral ablations of the contiguous visual areas, and cooling loops were placed in the pMS sulcus, and in contact with adjacent area 7 or posterior ectosylvian (PE) cortex of the opposite hemisphere. In both instances cooling of pMS cortex, but neither area 7 nor PE, restored a virtually normal level of orienting performance to stimuli presented anywhere in the previously hemianopic field. The reversal was highly sensitive to the extent of cooling deactivation. In a third cat, cooling deactivation of the superficial layers of the contralateral superior colliculus also restored orienting performance to a cortical ablation-induced hemianopia. This reversal was graded from center-to-periphery in a temperature-dependent manner. Neither the cortical ablation nor any of the cooling deactivations had any impact on an auditory detection and orienting task. The deactivations were localized and confirmed by reduced uptake of radiolabeled 2-deoxyglucose to be limited to the immediate vicinity of each cooling loop. The results are discussed in terms of excitation and disinhibition of visual circuits.     

Subcortical auditory input to the primary visual cortex in anophthalmic mice

Anatomical and imaging studies show ample evidence for auditory activation of the visual cortex following early onset of blindness in both humans and animal models. Anatomical studies in animal models of early blindness clearly show intermodal pathways through which auditory information can reach the primary visual cortex. There is clear evidence for intermodal corticocortical pathways linking auditory and visual cortex and also novel connections between the inferior colliculus and the visual thalamus. A recent publication [L.K. Laemle, N.L. Strominger, D.O. Carpenter, Cross-modal innervation of primary visual cortex by auditory fibers in congenitally anophthalmic mice, Neurosci. Lett. 396 (2006) 108–112] suggested the presence of a direct reciprocal connection between the inferior colliculus and the primary visual cortex (V1) in congenitally anophthalmic ZRDCT/An mice. This implies that this mutant mouse would be the only known vertebrate having a direct tectal connection with a primary sensory cortex. The presence of this peculiar pathway was reinvestigated in the ZRDCT/An mouse with highly sensitive neuronal tracers. We found the connections normally described in the ZRDCT/An mouse between: (i) the inferior colliculus and the dorsal lateral geniculate nucleus, (ii) V1 and the superior colliculus, (iii) the lateral posterior nucleus and V1 and between (iv) the inferior colliculus and the medial geniculate nucleus. We also show unambiguously that the auditory subcortical structures do not connect the primary visual cortex in the anophthalmic mouse. In particular, we find no evidence of a direct projection from the auditory mesencephalon to the cortex in this animal model of blindness.     

Visual processing in scotomata

Summary In contrast with other animals, when the occipital cortex is damaged in man, blindness occurs in spite of intact retinal projections to subcortical centers in the midbrain. By a proper selection of stimuli and responses, however, it can be shown that some information about the visual stimulus may be processed in regions of cortical blindness, even though the stimulus is not seen. One striking example of such processing occurs when dark, rather than bright flashes of light are presented in the scotoma. In this case the dark bars may actually be discriminated better in the scotoma than they are in the intact portion of the visual field. The nature of the residual discrimination has the properties of a primitive stereoscopic mechanism that ignores the sign of the stimulus disparity.     

Pregnancy outcomes among visually impaired women in Washington State, 1987–2014

BackgroundWomen with visual impairment may have reduced ability to access standard care resources, however, information on their pregnancy and neonatal outcomes is limited.ObjectiveTo assess risk of adverse pregnancy and neonatal outcomes among visually impaired women in Washington State from 1987 to 2014.MethodsWe conducted a retrospective cohort study using linked Washington State birth/fetal death hospital discharge records to compare outcomes among women with and without visual impairment noted at their delivery hospitalization. Pregnancy conditions and outcomes evaluated included gestational diabetes, pre-eclampsia, labor induction and cesarean delivery. Neonatal outcomes included preterm delivery and birth weight <2500 g. We assessed length of maternal and infant delivery hospitalization. We performed Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CIs) for each outcome, adjusting for year of delivery, maternal age, and parity.ResultsMost adverse pregnancy and neonatal outcomes were similar for visually impaired (N = 232) and comparison women (N = 2362). However, visually impaired women had increased risks of severe pre-eclampsia (RR 3.77, 95% CI 1.69–8.43), labor induction (RR 1.33, 95% CI 1.10–1.61) and preterm delivery (RR 1.60, 95% CI 1.06–2.42). They were also more likely to have delivery hospitalizations of 3 or more days following a vaginal (RR 1.86, 95% CI 1.41–2.47). Among cesarean deliveries, infants of visually impaired women had increased risk (RR 1.24, 95% CI 1.02–1.51) of hospitalization for 3 or more days postpartum.ConclusionOur findings may be useful for obstetric providers in counseling their visually impaired patients.     

北京市顺义县50岁及以上人群中盲患病率调查

目的 调查北京市顺义县５０岁及以上人群盲患病率,并与１９８５年调查结果相比较,以此评价近１０余年该县实施防盲治项目的效果。方法 １９９６年９～１１月采用整群随机抽样方法在顺义县抽取２８个调查点,对５０岁及以上人群进行视力和眼部检查。正式现场调查之前先进行预试验,并进行保证调查质量的重复性检验。结果 检录５５５５例中,受检人数为５０８４例,受检率为９１．５％。以世界卫生组织视力损伤为标准,盲患病率为