Seasonal allergic conjunctivitis is accompanied by increased mast cell numbers in the absence of leucocyte infiltration

Background Seasonal allergic conjunctivitis (SAC) is the most common allergic disease to affect the eye. occurring alone or in association with allergic rhinitis. Infiltration with mast cells and eosinophils is characteristic of the chronic forms of allergic conjunctivitis such as vernal and atopic keratoconjunctivitis. and these cell types also contribute significantly to allergic inflammation in the skin. Indirect evidence for a similar pattern of cellular events in SAC comes from studies which demonstrate raised eosinophil and neutrophil numbers in conjunctival scrapings and elevated levels of mast cell tryptase in tears following allergen challenge. Objective To directly characterize the inflammatory cell infiltrate in SAC and to determine its clinical relevance. Methods We employed specific immunohistochemical staining to count masi cells, eosinophiis and neutrophiis in the conjunctival epithelium and lamina propria of eight atopic patients with SAC in, and 12 SAC patients out of the hay fever season. Sixteen patients with no history of ocular allergy were used as control subjects. Results Mast cells were absent from normal epithelium. During the pollen season median mast cell numbers in the lamina propria were found to be increased by 6I'J(in patients with SAC compared with normals (P= 0.012). Eosinophils were found in the lamina propria in less than half of the symptomatic patients with SAC and in only three patients were eosinophils present in the epithelium. The neutrophil numbers in the lamina propria of patients with SAC tended to be higher than normals but these changes did not reach statistical significance. Conclusion Conclusion These data based on the direct assessment of conjunctival tissue provide evidence that symptoms occur in SAC in the absence of detectable recruitment of eosinophils or neutrophils. This suggests that this disorder is related to mast cell-mediated changes.     

Development of oculomotor functioning in preadolescence, adolescence, and adulthood

We examined developmental differences in smooth pursuit eye tracking proficiency in a large sample of preadolescent, adolescent, and adult males. Smooth pursuit was quantified using general measures of oculomotor functioning and by examining the frequency and dynamic characteristics of specific saccadic events. Examination of age effects using general measures indicated that, by late adolescence, the smooth pursuit system reached adult levels of functioning. No significant differences were found between the adolescent and adult groups on most global measures. However, both groups had better eye tracking than the preadolescent group, suggesting that during preadolescence the oculomotor system is still developing and is not yet capable of optimal performance. Examination of the frequency and dynamic characteristics of the saccadic events yielded additional information regarding the nature of the smooth pursuit eye tracking differences of the three age groups.     

Smooth eye movements evoked by electrical stimulation of the cat's superior colliculus

Head-fixed gaze shifts were evoked by electrical stimulation of the deeper layers of the cat superior colliculus (SC). After a short latency, saccades were triggered with kinematics similar to those of visually guided saccades. When electrical stimulation was maintained for more than 150–200 ms, postsaccadic smooth eye movements (SEMs) were observed. These movements were characterized by a period of approximately constant velocity following the evoked saccade. Depending on electrode position, a single saccade followed by a slow displacement or a staircase of saccades interspersed by SEMs were evoked. Mean velocity decreased with increasing deviation of the eye in the orbit in the direction of the movement. In the situation where a single evoked saccade was followed by a smooth movement, the duration of the latter depended on the duration of the stimulation train. In the situation where evoked saccades converged towards a restricted region of the visual field (goal-directed or craniocentric saccades), the SEMs were directed towards the centre of this region and their mean velocity decreased as the eye approached the goal. The direction of induced SEMs depended on the site of stimulation, as is the case for saccadic eye movements, and was not modified by stimulation parameters (place code). On the other hand, mean velocity of the movements depended on the site of stimulation and on the frequency and intensity of the current (rate code), as reported for saccades in the cat. The kinematics of these postsaccadic SEMs are similar to the kinematics of slow, postsaccadic correction observed during visually triggered gaze shifts of the alert cat. These results support the hypothesis that the SC is not exclusively implicated in the control of fast refixation of gaze but also in controlling postsaccadic conjugate slow eye movements in the cat.     

Cytology and intrinsic organization of the perihypoglossal nuclei in the cat

The morphology of the neurons in the perihypoglossal nuclei (nucleus prepositus, nucleus intercalatus, and nucleus of Roller) of the cat was studied in normal Nissl material, and by intracellular injection of horseradish peroxidase. The neurons in the nucleus prepositus were morphologically heterogeneous. Many of the cells in the ventromedial part of the caudal prepositus had relatively large somata, and complex dendritic trees which arose from numerous proximal dendrites and ramified extensively in the ventromedial aspect of the prepositus. These neurons had thick axons which typically did not give rise to local collaterals. The cells in the dorsolateral part of the caudal prepositus tended to have small somata, and dendritic trees which arborized in that region of the nucleus. The axons of these small cells frequently gave rise to local collaterals which terminated in the prepositus. Most of the cells in the prepositus had medium-sized somata and relatively few dendrites which branched in an isodendritic manner and extended for long distances, frequently leaving the nucleus. These "principal" prepositus neurons had axons which arborized unilaterally, and often gave rise to collaterals which terminated in either the ipsilateral or contralateral prepositus. The neurons in the nucleus of Roller and nucleus intercalatus which were intracellularly injected with horseradish peroxidase resembled the multidendritic and small prepositus cells, respectively. The intrinsic connectivity of the perihypoglossal nuclei was also studied by injecting horseradish peroxidase or 3H-leucine into the prepositus nucleus. The results of these experiments suggest that the perihypoglossal nuclei are highly interconnected bilaterally, although the large cells in the ventromedial prepositus and the nucleus of Roller contribute little to these intrinsic connections, and are not major recipients of intrinsic inputs. On the other hand, the magnitude of the reciprocal connections between the prepositus and the nucleus intercalatus suggests that they are functionally related.     

Are eye movement evoked potentials different from pattern reversal evoked potentials?

The averaged lambda wave elicited by saccadic eye movements across a checkerboard pattern has been reported to differ from checkerboard reversal evoked reponses, even when the electroencephalographic responses were corrected for the artefact caused by the movement of the dipole moment of the eye itself. Because of these differences it was suggested that the recording of the lambda wave might provide extra information in pathological circumstances. We performed experiments in which the parameters of the pattern (high contrast checkerboard pattern, 20 checks, large field 72 × 72 degrees) shift across the retina were carefully adjusted. For instance, eye movements were made across an integer and odd number of checks in order to mimic the pattern reversal. Furthermore, the timing of the pattern movement in the pattern reversal condition was adjusted so as to simulate the saccadic eye movement. The results seem to suggest that the reported dissimilarities between pattern reversal and eye movement evoked responses can be accounted for by the small differences of the retinal shift in the two conditions.     

Saccadic anomalies: vergence induces large departures from ball-and-socket behavior

The configuration of muscular forces, which maintains a given orientation of the eye, varies with vergence state. As a consequence, changes in vergence produce both static and dynamic violations of simple ball-and-socket behavior: during strong convergence, the entire eye is displaced temporally within its orbit at steady state by as much as 200 microns; and the axis of ocular rotation for small horizontal saccades is consistently displaced forward within the globe by an average of about 1 mm. These phenomena occur regardless of whether vergence is maintained by accommodation or by binocular disparity. Hence, systematic errors of as much as a full degree can arise in measurement of vergence movement, unless monitoring methods are used which are insensitive to translational motion. The observed displacement on the axis of rotation for saccades may be involved in subjective shrinkage of visual targets during convergence ("experimental micropsia ").     

Prevalence of Vision Loss and Associations With Age-Related Eye Diseases Among Nursing Home Residents Aged ≥65 Years

ObjectivesTo examine data from Delaware nursing homes to determine prevalence of age-related eye diseases (AREDs), vision impairment, and blindness and to compare the findings with the results of 11 US investigations of vision and eye health in nursing homes.DesignThis is a cross-sectional, retrospective study of nursing home patients.Setting and ParticipantsTwenty nursing homes in Delaware participated in the study, yielding comprehensive eye examination records for 2019 study participants.MethodsSummary statistics and regression analyses.ResultsThe overall prevalence of vision impairment or blindness was 63.8% and was above 60% for each age, sex, and race category. Prevalence of vision impairment or blindness was 68.4% among patients with cataracts, 69.4% among patients with macular degeneration, 70.5% among patients with glaucoma, and 68.4% among patients with diabetic retinopathy. Prevalence of blindness was 14.1%. Among patients with AREDs, prevalence of blindness ranged from 15.0% for patients with cataracts to 22.6% for patients with diabetic retinopathy. When compared with other investigations, we found wide variation in vision and eye factors reported and wide variation in the prevalence of those factors. Only 4 studies diagnosed both AREDs and visual function. Seven studies reported AREDs, and 7 reported vision impairment and/or blindness. Vision impairment or blindness ranged from 29% to 67%; cataract ranged from 32% to 83%; macular degeneration ranged from 4.6% to 70.7%. Glaucoma ranged from 5.3% to 41.4%; diabetic retinopathy ranged from 1.7% to 3.1%.Conclusions and ImplicationsComprehensive eye examinations showed that vision impairment and blindness affected 63.8% of nursing home residents. Compared with other studies, there was a wide range of vision factors reported and wide variation in the prevalence of vision impairment or blindness and AREDs. This investigation suggests the importance of eye care in nursing homes and the importance of reporting standard vision and eye health factors to inform policy and practice.     

藿香正气片增强镇静催眠药的镇静与催眠作用的研究

目的研究藿香正气片增强镇静催眠药对小鼠的镇静催眠作用.为临床增添了一个中西药结合的镇静催眠合剂提供药理依据.方法应用抖笼换能器法观察藿香正气片对小鼠的自发活动的影响.由此观察藿香正气片与镇静催眠药的协同作用.测定藿香正气片与镇静催眠药对小鼠的入睡时间及睡眠持续时间的作用.两个实验均分成四组,生理水组、藿香正气片组、安定组、安定+藿香正气片组.结果1.对小鼠自发活动的影响.(1)藿香正气片组与生理盐水组比较,具有极显著性差异(P＜0.01).(2)安定组与安定+藿香正气片组比较具有显著性差异(P＜0.05).2.藿香正气片增强镇静催眠药对小鼠的睡眠作用.(1)藿香正气片组与生理盐水组比较具有显著性差异(P＜0.05).(2)藿香正气片+安定组与安定组比较具有极显著性差异(P＜0.01).结论藿香正气片与安定合用对镇静及催眠确有协同作用.     

44例裂孔性视网膜脱离的暗适应视网膜电图及振荡电位的观察

目的：检测裂孔性视网膜脱离患者的视网膜电图（FERG）及振荡电位（OPs),总结FERG及OPs在视网膜脱离中的变化规律。方法：随机选择1眼为裂孔性视网膜脱离,另1眼除屈光不正外无其他眼疾中44例、44眼,进行暗适应FERG及OPs的检测。与对侧眼作比较研究,主要观察指标有：FERG中的a波振幅（aA);b波振幅（bA);a波峰时（aT);b波峰时（bT),OPs中的∑O,O1,O2,O3,O4及其峰时值的变化。结果：全部病例均有病理改变,视网膜脱离眼上述指标与对侧眼差异有显著性（P＜0．05）,降低幅度与视网膜脱离面积有关。视网膜脱离眼FERG的a波振幅、b波振幅与手术效果相关,异常程度轻者手术成功率高。结论：视网膜电图检查是了解视网膜机能的有效方法之一,术前检查视网膜脱离患者的FERG及OPs,有助于了解病变严重程度及视功能损害的情况,能对手术预后做出较适合的估计。     

幼兔近视模型及大光明护眼液的疗效

目的 :探讨学生近视眼的发病机制和有效治疗药物。方法 :选用 2 0只新西兰纯种幼兔建立近视模型 ,然后分别采用2种药物和生理盐水治疗。结果 :大光明护眼液治疗组的平均屈光度 (D)值为 (+ 2 5 0± 0 6 8)、平均裸眼觅食距离 (cm)值为(2 80 0 0± 2 7 30 )、平均体重 (g)增长值为 (72 6 0 0± 31 30 ) ;而珍视明滴眼液治疗组和生理盐水治疗组近视屈光度 (D)值分别为(+ 1 6 6± 0 2 9)和 (+ 0 85± 0 42 ) ,平均裸眼觅食距离 (cm)分别为 (2 5 6 0 0± 5 4 48)和 (196 0 0± 76 48) ,平均体重 (g)增长分别为 (6 2 2 0 0± 31 94)和 (5 6 0 0 0± 6 2 85 )。结论 :(1)长期限制视距、微弱光线照射和经常习惯性近距离视物是造成近视眼的直接因素 ;(2 )采用大光明护眼液治疗近视眼的疗效明显 ,优于珍视明滴眼液和生理盐水治疗组 (P <0 0 1)。