中老年人角膜内皮细胞分析和中央角膜测厚

目的利用非接触式自动角膜内皮计对较大样本中老年人角膜内皮细胞和角膜中央厚度进行分析,获得其结构参数的生理正常值范围。方法对670例中老年白内障患者术前角膜内皮检查资料进行回顾性分析。206例采用Topcon内皮计,464例采用Humphrey内皮计。相关结构参数包括内皮细胞密度,内皮细胞平均面积,最大和最小面积,面积标准差和变异系数,六边形细胞所占比例,以及中央角膜厚度。结果统计资料平均年龄(69±9)岁(41～94岁)。Topcon内皮计和Humphrey内皮计单纯白内障患者平均角膜内皮细胞密度分别为(2683±417)个/mm2和(2696±404)个/mm2,均有随年龄增长而下降的趋势,60岁上下出现较显著性差异。内皮细胞平均面积分别为(381±65)μm2和(381±75)μm2。Topcon内皮计测得平均中央角膜厚度为(0.541±0.037)mm。Humphrey内皮计测得六边形细胞所占比例为(53±10)%。白内障合并青光眼患者65例,其平均细胞密度显著低于单纯白内障患者(p<0.01),平均细胞面积显著增大(p<0.01)。结论中老年人眼角膜内皮细胞数量和大小仍随年龄变化而改变,60岁上下出现较显著性差异。了解不同年龄段人群的角膜内皮参数正常值有助于为各类眼病治疗或内眼手术提供安全保障。Topcon内皮计和Humphrey内皮计的测量结果具有可比性。     

Wide-field fusional stimulation in strabismus

The effectiveness of wide-field fusional stimulation was evaluated on 57 strabismics and 29 patients with convergence insufficiency. The strabismics had fusion, normal retinal correspondence (even if it coexisted with anomalous retinal correspondence), a deviation not exceeding 30 delta, and visual acuity of 6/7.5 or better. The strabismics included intermittent exotropes, surgically overcorrected intermittent exotropes, and accomodative esotropes. Of these strabismic patients, 42 responded to therapy in which tropias were converted to phorias or the frequency of the manifest deviation was significantly reduced, fusional amplitudes were significantly enlarged, and in many cases, stereoacuity improved as well. In 16 cases, surgery that was recommended before treatment is no longer being considered. Of the patients with convergence insufficiency, 23 responded to therapy which resulted in the enlargement of fusional amplitudes and the alleviation of symptoms. Follow-up visits (for up to 5 years) confirm that the improvement persists, which indicates the utility and effectiveness of this technique.     

Wide-field ganglion cells in macaque retinas

To describe the wide-field ganglion cells, they were injected intracellularly with Neurobiotin using an in vitro preparation of macaque retina and labeled with streptavidin-Cy3. The retinas were then labeled with antibodies to choline acetyltransferase and other markers to indicate the depth of the dendrites within the inner plexiform layer (IPL) and analyzed by confocal microscopy. There were eight different subtypes of narrowly unistratified cells that ramified in each of the 5 strata, S1-5, including narrow thorny, large sparse, large moderate, large dense, large radiate, narrow wavy, large very sparse, and fine very sparse. There were four types of broadly stratified cells with dendritic trees extending from S4 to S2. One type resembled the parvocellular giant cell and another the broad thorny type described previously in primates. Another broadly stratified cell was called multi-tufted based on its distinctive dendritic branching pattern. The fourth type had been described previously, but not named; we called it broad wavy. There was a bistratified type with its major arbor in S5, the same level as the blue cone bipolar cell; it resembled the large, bistratified cell with blue ON-yellow OFF responses described recently. Two wide-field ganglion cell types were classified as diffuse because they had dendrites throughout the IPL. One had many small branches and was named thorny diffuse. The second was named smooth diffuse because it had straighter dendrites that lacked these processes. Dendrites of the large moderate and multi-tufted cells cofasciculated with ON-starburst cell dendrites and were, therefore, candidates to be ON- and ON-OFF direction-selective ganglion cells, respectively. We concluded that there are at least 15 morphoplogical types of wide-field ganglion cells in macaque retinas.     

A system for counting endothelial cells from transparencies and negatives.

We have developed a system for endothelial cell density calculation and morphologic examination, which has proven to be convenient and reproducible, by using a currently available viewing unit, a few inexpensive materials, and simple arithmetic.     

两种计数方式在角膜内皮细胞形态特征分析中的一致性评价

目的探讨计算机自动计数和手工辅助计数在角膜内皮细胞形态特征分析中的差异,为较准确进行角膜内皮细胞计数提供指导。方法回顾性分析和前瞻性记录来本院行角膜内皮细胞计数的患者53例（100只眼）,应用t检验和Bland-Altman分析评价两种计数方法所获结果的一致性。结果在中、低密度组（〈2500 cell.mm-2）,两种方法测得的细胞面积变异系数（Scv）和细胞密度（CD）差异有统计学意义（均为P〈0.05）,角膜内皮细胞数和六边形细胞百分比（H%）差异均无统计学意义。在高密度组（〉2500 cell.mm-2）,两种方法测得的角膜内皮细胞数、Scv差异均有统计学意义（均为P〈0.05）,而CD和H%差异均无统计学意义。但Bland-Altman分析表明中、低密度组角膜内皮细胞数、Scv、CD和H%的一致性均欠佳,高密度组角膜内皮细胞数、Scv和CD的一致性良好,而H%一致性仍欠佳。结论 Bland-Altman分析给出了更合理的结果,对于高密度的正常角膜内皮细胞行自动计数能提供较可靠的结果,对于自动计数错误的细胞（尤其是低密度细胞）行辅助计数,能为临床提供更加准确的角膜内皮细胞生物学参数。     

Wide-field contact specular microscopy analysis of corneal endothelium post trabeculectomy

Graefe's Archive for Clinical and Experimental Ophthalmology - This study investigates the possible role of the filtration bleb in the continuous decrease in corneal endothelial cell (CEC)...     

广角数码儿童视网膜成像系统引导下激光光凝治疗早产儿视网膜病 变

目的 观察在广角数码儿童视网膜成像系统（RetCam II）在激光 光凝治疗早产儿视网膜病变（ROP）中的应用价值。 方法 回顾分析连续 发现的阈值ROP或阈值前Ⅰ型ROP患儿共30例58只眼， 其中36只眼为阈值前Ⅰ型ROP，19只眼为阈值ROP，3只眼为外院冷冻术后有冷冻遗漏 区ROP；1区ROP 8只眼，2区ROP 50只眼。54只眼 （93.1％）进行了一次激光光凝， 4只眼（6.9％）进行了2次激光光凝。 应用半导体532 nm激光经双目间接检眼镜激光光凝周边视网膜无血管区。手术前后 分别进行RetCam II眼底检查，手术中对激光光凝遗漏区即刻进行补充治疗。治疗后随访时 间3～11个月，平均5-5个月。 结果 54只眼1次激光光凝术后1～3周反 应良好，ROP病变得到控制。4只眼行第2次激光光凝术后，2只眼病变静止、消退；2只眼发 生后极 部局限性牵拉性视网膜脱离。随访结束时2只眼（3.4％）发生视网膜不良结构后果。 结论 激光光凝手术前后行RetCamⅡ检查在治疗ROP时能够有效避免激光光凝 “遗漏区”，提高一次激光光凝成功 率，减少手术后视网膜不良结构后果发生率。     

Standard microlithographic mosaics to assess endothelial cell counting methods by light microscopy in eye banks using organ culture

PURPOSE: To develop standard microscopic hexagonal mosaics mimicking the human corneal endothelium for quality control of endothelial cell density (ECD) measurement and verification of cell counting strategy by light microscopy in eye banks using organ culture. METHODS: A standard slide, the Keratotest, was developed with 10 laser-engraved mosaics and different predetermined "cell" densities representing the range of ECDs observed routinely. Horizontal and vertical micrometric scales were etched adjacently to each mosaic, and a standard microscopy resolution test pattern was included. The Keratotest was applied to assess the reliability of a computer-assisted analyzer developed for corneal endothelial evaluation based on light microscopy images. RESULTS: The Keratotest consisted of 10 microlithographic homogeneous mosaics of 1-mm2 printed area and 1.2-microm cell boundary thickness. The micrometric scale associated with each mosaic aided in simultaneous verification of microscope calibration, and the test pattern aided in checking the microscope resolution. The design was unalterable and reproducible, and the glass slide incorporated in a carbon fiber support ensured easy handling and safe transport. Evaluation of the Keratotest mosaics by the computer-assisted analyzer found a high level of agreement (error margin between +0.12 and -0.46%) with the laser-engraved cell density. CONCLUSIONS: This prototype device enabled assessment of reliability of ECD measurement in eye banks. It also allowed verification of the calibration and resolution of light microscopes. Periodic validation of counting procedure in eye banks with mosaics of known "cell" densities should be useful for standardization of donor corneal tissue quality control.     

Wide-field handheld high frequency ultrasonography using a variable high frequency ultrasound system.

Wide-field handheld high frequency ultrasonography using a variable high frequency ultrasound system is an imaging modality in the frequency range of 35 to 50 MHz. Using a water bath immersion technique, high-resolution digital movies obtained from a variety of anterior segment ocular conditions were particularly helpful in establishing the diagnosis in each case. Images taken with the wide-field limbus-to-limbus mode provided a comprehensive picture of large and extensive lesions, whereas the focal mode was for small to medium lesions or specific areas of interest.     

Wide-field imaging and OCT vs clinical evaluation of patients referred from diabetic retinopathy screening

Purpose

Compare wide-field Optomap imaging and optical coherence tomography (OCT) with clinical examination in diabetic retinopathy (DR).

Methods

Patients referred from Diabetic Eye Screening Programmes to three centres underwent dilated ophthalmoscopy and were assigned a DR grade. Wide-field colour imaging and OCT were then examined by the same clinician at that visit and a combined grade was assigned. Independent graders later reviewed the images and assigned an imaging-only grade. These three grades (clinical, combined, and imaging) were compared. The method that detected the highest grade of retinopathy, including neovascularisation, was determined.

Results

Two thousand and forty eyes of 1023 patients were assessed. Wide-field imaging compared with clinical examination had a sensitivity and specificity of 73% and 96%, respectively, for detecting proliferative DR, 84% and 69% for sight-threatening DR, and 64% and 90% for diabetic macular oedema. Imaging alone found 35 more eyes with new vessels (19% of eyes with new vessels) and the combined grade found 14 more eyes than clinical examination alone.

Conclusions

Assessment of wide-field images and OCT alone detected more eyes with higher grades of DR compared with clinical examination alone or when combined with imaging in a clinical setting. The sensitivity was not higher as the techniques were not the same, with imaging alone being more sensitive. Wide-field imaging with OCT could be used to assess referrals from DR screening to determine management, to enhance the quality of assessment in clinics, and to follow-up patients whose DR is above the screening referral threshold but does not actually require treatment.     

Wide-field cone bipolar cells and the blue-ON pathway to color-coded ganglion cells in rabbit retina

Wide-field cone bipolar cells with sparse dendritic branching and proposed connectivity to blue cones were first identified in rabbit and cat. In rabbit, these were subdivided into type a (wa) and type b (wb), with axonal branching in sublamina a, and sublamina b, respectively, of the inner plexiform layer (IPL). Recent studies in rabbit support the earlier hypothesis of exclusive blue/short wavelength cone connectivity for both types. The homologues of wb cells (but not wa cells) have been identified in other mammals. The axonal branching of wa cone bipolar cells is shown to co-stratify with the dendrites of the "fiducial," type a starburst amacrine cell, although a few branches extend into sublamina b. The axon terminal of wb cone bipolar cells is shown to be narrowly stratified in stratum 5alpha, deep to the dendrites of the type b starburst amacrine cell. Rabbit ganglion cells postsynaptic to wa cells are unknown, but may include class III.2a cells, similarly stratified in the IPL. The wb axon terminal is shown here to co-stratify with and to make close, likely synaptic, contacts with the dendrites of a recently described morphological subtype of class II ganglion cell in rabbit retina, IIb2. Recent morpho-physiological correlation indicates that class IIb2 cells correspond to the blue-ON-center-X or ON-brisk-sustained ganglion cells, defined physiologically in rabbit. In contrast, the wb cell in cat retina must innervate the physiologically identified blue-ON-center-sluggish-sustained ganglion cell. In monkey retina, the wb-like bipolar cells apparently innervate a small, partly bi-stratified ganglion cell. Mammals share a common pathway from short-wavelength-sensitive (S/blue) cone photoreceptors to ON-center ganglion cells in sublamina b of the IPL, in the form of wb or wb-like cone bipolar cells, but the type of ganglion cell innervated appears to be particular, and may serve different functional roles in different mammalian orders.     

The role of small saccades in counting

Eye movements were recorded by a contact lens optical lever while subjects counted a repetitive pattern of closely spaced bars (7′–14′ apart) in a 2° field by either making saccades or maintaining the line of sight without saccades. Counting accuracy was slightly greater without saccades than with saccades even when saccade size approximated the separation of the bars. Saccades did improve counting accuracy when displays contained haphazardly-arranged odd shapes that easily formed distinct perceptual groups.Next, we considered possible reasons why saccades improved counting accuracy with such displays and found that saccades were not needed to solve problems requiring visual imagery as has been proposed. Also, that a single saccade did not necessarily accompany each attention shift during counting. These results do not support proposals that counting accuracy is limited by oculomotor skill. Rather, they suggest that counting accuracy is limited by perceptual confusion in the display.     

Multisensory effects differ for counting small and large pulse numbers

In Illusory Flash (IF) experiments, congruent multisensory presentation has no effect on the mean estimate of the number of events, but decreases the variance in comparison with unisensory presentation. In contrast, congruent multisensory presentation in other Temporal Numerosity Judgement (TNJ) tasks affects the mean estimate (i.e., it often results in a reduction in underestimation) and increases the variance. In three experiments, we investigated the differences between both paradigms as possible causes of this discrepancy: the presence or absence of incongruent stimuli (Experiment 1), the instruction to the observer to either count flashes, beeps or multisensory events (Experiment 2), and the range of pulses presented (Experiment 3). We found significant differences between the mean numerosity estimate of multisensory and unisensory series in Experiment 3, but not in 1 and 2. This suggests that the difference in the range of pulses presented in IF (1-3 pulses) and TNJ (1-10 pulses) is the primary cause of the discrepancy. In the discussion we propose that this result may be explained by the use of two different strategies and their susceptibility to multisensory presentation. For small pulse numbers, observers can accurately count both unisensory and multisensory pulses. For larger numbers, observers can no longer count but will estimate the number based on the pulse series duration which is improved for multisensory stimuli.