OCTA对青少年近视人群视网膜微血管密度的观察

目的：基于光学相干断层扫描血管成像（OCTA）技术探讨青少年儿童近视与视网膜表层微血管密度 及视网膜厚度的相关性。方法：横断面研究。共纳入2018年5─11月于四川大学华西医院眼科门 诊就诊的7～14岁青少年近视患者105例（193眼）。对所有受检者进行光学相干断层扫描（OCT）和 OCTA检查，量化分析黄斑中心凹视网膜厚度和各部位视网膜表层微血管密度。单因素方差分析比 较低、中、高度近视组各部位视网膜微血管密度及视网膜厚度的差异。采用Pearson相关系数探讨视 网膜厚度与各部位视网膜表层微血管密度的相关性。Spearman相关系数用于探讨等效球镜与中心凹、 旁中心凹视网膜表层微血管密度以及视网膜厚度的关系；分段多项式函数分析等效球镜度与外环及 直径6 mm完整视网膜表层微血管密度的关系。结果：旁中心凹、外环、直径6 mm完整区域视网膜 表层微血管密度在低、中、高度近视组间比较差异均具有统计学意义（F=11.651、14.499、14.232， 均P<0.001）。年龄与中心凹视网膜厚度之间有较弱正相关关系（r=0.187，P=0.011），与各部位微血管 密度均无相关性。等效球镜度与旁中心凹视网膜微血管密度有相关性（r=-0.301，P<0.001），与外环、 直径6 mm完整区域视网膜表层微血管密度呈曲线相关（r=-0.319，P<0.001；r=-0.307，P<0.001）。 但与中心凹视网膜表层微血管密度及视网膜厚度无显著相关性。此外，中心凹处视网膜厚度与微血 管密度呈正相关（r=0.691，P<0.001），与其余部位微血管密度无相关性。结论：青少年近视程度数 与旁中心凹、外环及直径6 mm完整区域视网膜表层微血管密度呈负相关；中心凹处视网膜厚度与年 龄、微血管密度呈正相关。     

The relationship between the Stiles–Crawford effect of the first kind (SCE-I) and myopia

The Stiles-Crawford effect of the first kind (SCE-I) was measured on both emmetropic and myopic subjects at six different retinal locations. The results revealed a number of significant discrepancies in receptor alignment between the groups of different refractive errors. In myopic subjects, the receptors in the nasal retina (i.e. between the fovea and the optic nerve head) were found to be aligned nasally towards the optic nerve head, whereas the receptors in the temporal retina were aligned towards the centre of the exit pupil. In emmetropic subjects, the receptors across the retina were finely tuned towards the centre of the exit pupil. The magnitude of the receptor displacement in myopic subjects was found to be directly associated with the length of the eyeball.     

胎儿筛骨的形态学研究

本文从组织学角度,研究胎儿筛骨的形态学变化以及水平板、纸板和筛凹的发育特点。结果表明:筛骨整体(在冠状位)呈等腰梯形,即纸板为梯形的两边;胎儿期的纸板在水平切面上呈向外凹的骨板,至出生时呈轻微的“S”形弯曲;胚胎第24周后,水平板的外侧部分逐渐形成筛凹,并随筛窦的气化而变薄,形成筛窦的顶部。上述结果提示:出生时其眶内侧壁(主要为纸板)结构不呈矢状平面,且与水平板间的角度(斜度)随胎龄增长而增大(P<0.01);筛骨水平板则由内侧部分的筛板和外侧部分的筛凹组成。     

The human motion onset VEP as a function of stimulation area for foveal and peripheral vision

We studied amplitude of the wave N200 of the motion-onset VEP by varying the side length of a square stimulation field between 0.5 and 7 degrees. A significant increase in amplitude was obtained between 0.5 and 1 degree of side length in central stimulation and between 0.5 and 5 degrees in 10-degree peripheral stimulation. Variations of spatial frequency between 0.34 and 6.8 c/deg did not modify the amplitude size, ie, no tuning effect could be found. The results of simultaneous and separate stimulation of foveal and parafoveal regions support the observation that the stimulation field size is a minor influence. Features of motion-sensitive cortical neurons, such as those found in monkeys, could account for this behavior.     

Re-evaluating split-fovea processing in word recognition: Effects of fixation location within words

It has been claimed that word recognition is affected fundamentally by the precise location at which a word is fixated because a precise split in hemispheric processing at the point of fixation causes all letters to the left and right of fixation to project to different, contralateral hemispheres. To assess this claim, 5-letter words (and nonwords) were presented for lexical decision when participants fixated the space immediately to the left (location 1) or right (location 6) of each stimulus, or one of the four possible inter-letter spaces (locations 2-5). Fixation location was controlled using an eye-tracker linked to a fixation-contingent display and all stimuli were presented entirely within foveal vision to avoid confounding influences of extrafoveal hemispheric projections. Performance was equally poorest when fixating locations 1 and 6 (when words were shown entirely to either the right and left of fixation), intermediate for location 5, and equally superior for locations 2, 3, and 4. Additional word-specific analyses also showed no evidence of the effects of fixation location on optimal word recognition predicted by split-fovea processing. These findings suggest that, while fixation location influences word recognition, word recognition is apparently not affected by a split in hemispheric processing at the point of fixation and does not depend critically on the precise location at which a word is fixated. Implications of these findings for the role of fixation location in word recognition are discussed.     

Topographic Distribution and Progression of Soft Drusen Volume in Age-Related Macular Degeneration Implicate Neurobiology of Fovea

PurposeTo refine estimates of macular soft drusen abundance in eyes with age-related macular degeneration (AMD) and evaluate hypotheses about drusen biogenesis, we investigated topographic distribution and growth rates of drusen by optical coherence tomography (OCT). We compared results to retinal features with similar topographies (cone density and macular pigment) in healthy eyes.MethodsIn a prospective study, distribution and growth rates of soft drusen in eyes with AMD were identified by human observers in OCT volumes and analyzed with computer-assistance. Published histologic data for macular cone densities (n = 12 eyes) and in vivo macular pigment optical density (MPOD) measurements in older adults with unremarkable maculae (n = 31; 62 paired eyes, averaged) were revisited. All values were normalized to Early Treatment Diabetic Retinopathy Study (ETDRS) subfield areas.ResultsSixty-two eyes of 44 patients were imaged for periods up to 78 months. Soft drusen volume per unit volume at baseline is 24.6-fold and 2.3-fold higher in the central ETDRS subfield than in outer and inner rings, respectively, and grows most prominently there. Corresponding ratios (central versus inner and central versus outer) for cone density in donor eyes is 13.3-fold and 5.1-fold and for MPOD, 24.6 and 23.9-fold, and 3.6 and 3.6-fold.ConclusionsNormalized soft drusen volume in AMD eyes as assessed by OCT is ≥ 20-fold higher in central ETDRS subfields than in outer rings, paralleling MPOD distribution in healthy eyes. Data on drusen volume support this metric for AMD risk assessment and clinical trial outcome measure. Alignment of different data modalities support the ETDRS grid for standardizing retinal topography in mechanistic studies of drusen biogenesis.     

儿童隐匿性高度近视黄斑区视网膜厚度分析

目的：观察分析隐匿性高度近视儿童黄斑区视网膜厚度变化及其相关因素。

方法：前瞻性非随机对照研究。选取2019-09/2020-09在承德医学院附属医院眼科门诊首次就诊且未进行过任何近视矫正训练的儿童56例110眼纳入研究,根据儿童近视的临床表现分为隐匿性高度近视组(27例52眼)和对照组(29例58眼,普通近视儿童)。比较两组儿童黄斑各分区视网膜厚度情况,分析隐匿性高度近视儿童黄斑中心凹平均视网膜厚度与基线资料的相关性。

结果：隐匿性高度近视儿童黄斑区视网膜厚度以黄斑中心凹最薄,内环区上方最厚。隐匿性高度近视组儿童黄斑9个分区平均视网膜厚度均较对照组变薄,其中黄斑中心凹、外环区下方和颞侧处视网膜厚度有显著差异(均P<0.05)。随着隐匿性高度近视儿童屈光度的增高,黄斑各分区的平均视网膜厚度值均降低。与对照组相同屈光度儿童比较,隐匿性高度近视组除0.00D≤屈光度≤-1.00D儿童外环区颞侧、-2.00D<屈光度≤-3.00D儿童黄斑中心凹平均视网膜厚度有明显差异(均P<0.05),其余各分区平均视网膜厚度均无差异(P>0.05)。Pearson相关分析结果显示,隐匿性高度近视儿童黄斑中心凹平均视网膜厚度与性别、年龄、眼轴、眼压、角膜曲率均无相关性(P>0.05),与屈光度呈负相关性(r=-0.201,P<0.05)。

结论：隐匿性高度近视儿童黄斑视网膜厚度以黄斑中心凹最薄,内环区上方最厚,黄斑各分区平均视网膜厚度较相应屈光度数近视儿童薄。隐匿性高度近视儿童黄斑中心凹平均视网膜厚度与屈光度呈负相关。     

OCTA测量近视人群视网膜血管密度及中心凹无血管区的研究进展

光学相干断层扫描血管成像（OCTA）作为近几年不断发展的一项新兴技术,可以快速无创地得到高分辨率的眼底视网膜成像,并可以得到眼底血管密度及中心凹无血管区面积的量化值,为研究近视疾病早期的眼底病变提供极大帮助。现回顾OCTA的发展史,详细介绍并总结OCTA测量近视人群眼底视网膜血流变化及其影响因素,及辅助病理性近视诊断的...     

近视眼LASIK后黄斑区视网膜厚度变化的研究

目的 探讨准分子激光角膜原位磨镶术（exdmer laser insitu keratomileusis LASIK）对近视眼黄斑区视网膜厚度的影响及其影响因素。方法 随机选择接受LASIK手术矫正视力≥1．0近视眼患者25例49眼，根据术前屈光度数分为二组：中轻度近视组：≤6．00D，17眼；高度近视组：＞6．00D，32眼。采用Zeiss-Humphrey光学相干断层成像仪（Optical Coherence Tomography OCT）第三代观察近视眼LASIK术前，术后1d、3d、1w、1m眼底黄斑区变化，并测量以黄斑中心凹为中心3mm半径内的视网膜平均厚度，以地形图分9个区域显示。结果 25例49眼近视患者LASIK术后1d、3d黄斑中心凹（A1）视网膜平均厚度同术前比较有增加，差别具有统计学意义（P＜0．05；P＜0．01），近视眼术后1w、1m黄斑中心凹视网膜平均厚度同术前比较差别无统计学意义（P＞0．05）：除黄斑中心凹（A1区）外的近视眼黄斑部各区（A2-A9）视网膜平均厚度术后同术前比较差别无统计学意义（P＞0．05）。高度近视眼组术后1d、3d、1w黄斑中心凹（A1区）视网膜平均厚度均高于术前，差异具有统计学意义（P＜0．05；P＜0．01；P＜0．05），高度近视眼组术后1m黄斑中心凹视网膜平均厚度同术前比较差异无统计学意义（P＞0．05）；中轻度近视组术后观察各时期与术前比较差异无统计学意义（P＞0．05）。高度近视眼LASIK术后黄斑中心凹视网膜平均厚度的增加与术前屈光状态、激光切削时间呈正相关。结论 近视眼LASIK术后出现的黄斑中心凹视网膜水肿主要发生在高度近视眼，与术前屈光度数大、激光切削时间长有关。高度近视眼LASIK术后出现的黄斑中心凹水肿是轻微的，可逆的，未影响视力，在1m内消退。     

右心耳壁厚及梳状肌间凹深度测定对起搏电极定位的意义

目的 通过测量右心耳壁厚度及梳状肌间凹深度，为临床心房起搏电极的定位提供解剖学基础。方法 将50具经福尔马林处理尸体的右心耳，按水平距离和垂直距离分成内上、外上、内中、外中、内下、外下6个区域，测量各区的心肌壁厚度及梳状肌间凹。另用5具尸体于福尔马林处理前后行上述数据测定，以获得心壁厚度和梳状肌间凹深度的增减百分率，并对50具处理尸体的测值作校正。结果 50具经福尔马林处理尸体和5具未经福尔马林处理尸体的心耳壁厚度和梳状肌间凹的深度作比较，无统计学差异（P〉0．05）；但女性右心耳较男性小（P〈0．05）。结论 经福尔马林处理尸体的测值校正后能反映新鲜尸体的情况。右心耳内上、外上区域（梳状肌间凹的深度〉6mill）适宜翼状电极定位。内上、外上及内中区域（心耳壁厚度≥2mm）用螺旋电极定位是安全的；女性患者电极定位要注意安全。