实验性视网膜脱离复位后的视网膜细胞超微结构观察

目的 研究视网膜脱离复位后视网膜超微结构改变,以探讨视功能恢复障碍的机制。方法 12只灰兔通过在视网膜下注射透明酸钠的方法建立视网膜脱离模型。用透射电镜观察术后1,2,3,4周的视网膜。结果 视网膜复位早期光感受器外节段缺失、断裂。内节、视细胞核、双极细胞、神经节细胞均可见胞浆水肿,线粒体肿胀和嵴断裂。复位3周后,视网膜细胞结构基本正常,但仍有部分外节变短,神经纤维空洞存在。结论 视网膜复位后不仅光感受器,而且视网膜其他细胞和神经纤维均有不可逆的改变,这些改变导致视功能恢复不良。     

Retinal dialysis

Retinal dialysis is a disinsertion of the sensory retina at the ora serrata. Dialysis may result from ocular trauma or occur as a spontaneous non-traumatic event. Dialyses are often asymptomatic and associated with a slowly progressing secondary retinal detachment. They show a predilection for the inferotemporal retinal quadrant. Retinal dialysis is the major cause of retinal detachment in children and young adults. Two cases of spontaneous retinal dialysis are presented. These cases represent extremes of the age spectrum for this condition.     

The effect of caffeine on retinal vessel diameter in young healthy subjects

Purpose: To investigate the effect of caffeine on retinal vessel diameter before and during flicker light stimulation in young healthy subjects. Methods: Seventeen healthy subjects (mean age: 29.6 ± 3.73 years, range: 22–35 years) were included in this study. The diameter of retinal vessels was measured continuously with the retinal vessel analyzer (RVA) before and 1 hr after 200 mg oral caffeine intake. After baseline assessment, a green luminance flicker of 20‐second duration was applied to stimulate retinal activity. The diameter of a segment of an arteriole and of a venule were measured during stimulation and 80 second after cessation of the stimulus. Flicker stimulation and 80‐second measurement interval were carried out three times. Blood pressure parameters, systemic mean arterial pressure (MAP), ocular perfusion pressure (OPP) and intraocular pressure (IOP) were obtained before and after oral caffeine intake. Results: The mean diameter of the arterioles at baseline before caffeine intake was 123.30 ± 14.0 μm (arithmetic mean ± standard deviation) and after caffeine 117.30 ± 13.0 μm which was significantly different (p = 0.004). The mean diameter of the venules at baseline before caffeine intake was 147.60 ± 19.5 μm and after caffeine 137.73 ± 19.9 μm which was significantly different (p = 0.005). The mean diameter of the arterioles during flicker light stimulation before caffeine intake was 126.65 ± 13.24 μm and after caffeine intake 121.59 ± 12.12 μm (p = 0.012). The mean diameter of the venules during flicker light stimulation before caffeine intake was 151.87 ± 18.63 μm and after caffeine intake was 145.14 ± 19.82 μm (p = 0.027). The flicker response of the arterioles increased from 2.8% before caffeine to 3.8% after caffeine intake (p = 0.010). The flicker response of the venules increased from 3.4% before caffeine to 5.5% after caffeine intake (p = 0.0001). Baseline diameters and diameters during flicker light stimulation after caffeine intake showed a significant negative correlation to the MAP for the arterioles (baseline: r = ?0.338, p = 0.049 and flicker: r = ?0.345, p = 0.046) and the venules (baseline: r = ?0.496, p = 0.003 and flicker: r = ?0.479, p = 0.004). Conclusions: The present study showed a significant vasoconstrictory response of the retinal vessels 1 hr after caffeine intake in young healthy subjects. Retinal vessel diameter changes were negatively correlated with MAP after caffeine consumption. These effects seem to be elicited by an autoregulatory response of the retinal vessels to the increased blood pressure changes after caffeine.     

Aggregations of retinal pigment epithelial cells on inferior retinal blood vessels,a clinical sign of early proliferative vitreoretinopathy

Purpose: To determine the relationship between ‘pigment clusters’ on blood vessels (BvRPE) on the inferior retina in patients with rhegmatogenous retinal detachment, and existing proliferative vitreoretinopathy (PVR). Methods: A prospective observational non‐comparative study of consecutive patients presenting with rhegmatogenous retinal detachment to a tertiary referral university department was performed. The retina was inspected preoperatively for the detection of BvRPE. A relationship with existing PVR was determined. Results: A total of 103 patients were recruited, 70 men and 32 women, mean age 56.7 years, with 57 left eyes. Mean duration of follow up was 9.2 months. Nineteen patients (18.4%) had BvRPE, and 20 had RPE clusters off blood vessels (nine had both). In those with the sign of BvRPE the mean number of RPE clusters on blood vessels was 5.7 (SD 5.8). The mean number of clock hours affected was 2.32 (SD = 1.58). Eight had B grade PVR and three C grade PVR. Patients with BvRPE were more likely to have PVR grades B or C than those without the sign (P = 0.002). The mean number of operations in those with the sign was 1.32 (SD = 0.58) and was statistically similar to those without BvRPE. Visual outcome was statistically similar in those with and without the sign. Conclusion: Patients with rhegmatogenous retinal detachment may demonstrate ‘pigment clusters’ on blood vessels in the inferior retina (BvRPE). This is likely to be a specific feature found in PVR and an early sign of activation of retinal pigment epithelial cells.     

视网膜脱离巩膜扣带术后后极部视网膜定量分析

目的:研究视网膜脱离(retinal detachment,RD)巩膜扣带术后后极部视网膜水肿情况。方法:应用视网膜厚度分析仪(RTA)对38例38眼孔源性RD巩膜扣带术后手术成功眼后极部视网膜厚度进行测量。结果:术后进行RTA测量随访的时间为72.61±57.27d,经RTA测量,RD术后黄斑中心凹平均厚度168.03±38.27μm,与对侧眼比较二者差异无显著性(P>0.05);RD眼术后后极部平均厚度175.50±33.85μm,与对侧眼比较二者差异无显著性(P>0.05),RD眼术后后极部最大厚度(310.18±158.40μm)与对侧眼比较,二者差异有显著性(P<0.01)。结论:通过RTA可精确测量并观察后极部视网膜水肿发生情况,视网膜脱离巩膜扣带术后2mo后极部视网膜局限性水肿仍存在,术后这个时间患者仍存在视物变形与此有关,仍需进行进一步的长期随访观察后极部视网膜水肿消退的时间。而且,在这段时间内考虑给予相应的干预治疗,以改善视功能。     

视网膜功能影像检查技术在视网膜疾病中的临床应用

新型的视网膜影像学技术能帮助我们更好地理解多种视网膜疾病的发病机制,如糖尿病视网膜病变、老年性黄斑变性、青光眼以及葡萄膜炎等.早期对这些疾病进行监测能够预防进行性视力丧失,同时在发展新型治疗方法上也起着重要的作用.视网膜功能影像检查技术是一种独特的非损伤性的功能性影像学检查技术.与目前临床上广泛使用的视网膜影像检查技术不同的是,视网膜功能影像检查技术不仅能显示视网膜结构上的改变,还能动态监测视网膜的功能状态和评估血流动力学参数,如监测视网膜血液流速、血氧状态等.本文即对这项视网膜功能影像检查技术在各种视网膜疾病中的应用进展作简要综述.     

视网膜血氧饱和度检测仪在眼部应用的研究进展

视网膜血氧饱和度检查是一种快速、无创的新型视网膜血管成像技术,可测量视网膜主要动脉及静脉的血氧饱和度并进行量化分析,可应用于视网膜动脉阻塞、视网膜静脉阻塞、糖尿病视网膜病变、老年性黄斑变性及青光眼等许多眼科疾病的诊断及随访,可有助于加深疾病的病因及发病机制的理解,并应用于疾病病情的评估及预后分析,是现有影像检查设备的重要补充.     

Ischemic retinal vein occlusion: characterizing the more severe spectrum of retinal vein occlusion

Retinal vein occlusion (RVO)-including central RVO, branch RVO, and hemicentral and hemispheric RVO—is the second most common vascular cause of visual loss, surpassed only by diabetic retinopathy. The presence and extent of retinal ischemia in RVO is associated with a worse prognosis. On this basis, most previously conducted studies considered ischemic retinal vein occlusion (iRVO) and non-iRVO as separate entities based on set thresholds of existing retinal ischemia as determined by fundus fluorescein angiography. Other diagnostic technologies have been used specifically in the differentiation of ischemic central retinal vein occlusion and nonischemic central retinal vein occlusion. To date, there is no fully accepted definition for iRVO. Some clinicians and researchers may favor establishing a clear differentiation between these forms of RVO; others may prefer not to consider iRVO as a separate entity. Whatever the case, retinal ischemia in RVO confers a higher risk of visual loss and neovascular complications; thus, it should be determined as accurately as possible in patients with this disease and be considered in clinical and experimental studies. Most recently conducted clinical trials evaluating new treatments for macular edema secondary to RVO included none or only few patients with iRVO based on previous definitions (i.e., few patients with sizeable areas of retinal ischemia were recruited in these trials), and thus it is unclear whether the results observed in recruited patients could be extrapolated to those with retinal ischemia. There has been scant research aiming at developing and/or testing treatments for retinal ischemia, as well as to prevent new vessel formation as a result of RVO. We provide a detailed review of the knowledge gathered over the years on iRVO, from controversies on its definition and diagnosis to the understanding of its epidemiology, risk factors and pathogenesis, the structural and functional effects of this disease in the eye and its complications, natural history, and outcomes after treatment. In each section, the definition of iRVO used is given so, independently of whether iRVO is considered a separate clinical entity or a more severe end of the spectrum of RVO, the information will be useful to clinicians to determine patient's risk, guide therapeutic decisions, and counsel patients and for researchers to design future studies.     

Influence of hypoxia on retinal progenitor and ganglion cells in human induced pluripotent stem cell-derived retinal organoids

AIM: To observe the effect of low oxygen concentration on the neural retina in human induced pluripotent stem cell (hiPSC)-derived retinal organoids (ROs). METHODS: The hiPSC and a three-dimensional culture method were used for the experiments. Generated embryoid bodies (EBs) were randomly and equally divided into hypoxic and normoxic groups. Photographs of the EBs were taken on days 38, 45, and 52, and the corresponding volume of EBs was calculated. Simultaneously, samples were collected at these three timepoints, followed by fixation, sectioning, and immunofluorescence. RESULTS: The proportion of Ki67-positive proliferating cells increased steadily on day 38; this proliferation-promoting effect tended to increase tissue density rather than tissue volume. On days 45 and 52, the two groups had relatively similar ratios of Ki67-positive cells. Further immunofluorescence analysis showed that the ratio of SOX2-positive cells significantly increased within the neural retina on day 52 (P<0.05). In contrast, the percentage of PAX6- and CHX10-positive cells significantly decreased following hypoxia treatment at all three timepoints (P<0.01), except for CHX10 at day 45 (P>0.05). Moreover, the proportion of PAX6-/TUJ1+ cells within the neural retinas increased considerably (P<0.01, <0.05, <0.05 respectively). CONCLUSION: Low oxygen promotes stemness and proliferation of neural retinas, suggesting that hypoxic conditions can enlarge the retinal progenitor cell pool in hiPSC-derived ROs.     

超声诊断视网膜裂孔伴视网膜脱离

目的 探讨超声诊断视网膜裂孔伴视网膜脱离的方法。方法 选取1999年11月～2000年7月眼科超声检查视网膜脱离伴明确裂孔的连续临床病例48眼,每眼均经过各个方位的超声探测。结果 当连续性脱离视网膜光带中有明显中断,且断端间距大于1mm时,可诊断为视网膜裂孔。马蹄形裂孔中18眼在孔前缘有玻璃体牵引,4眼PVD刚好至后缘,8眼在前后缘均有牵孔;黄斑裂孔中6眼在黄斑处有玻璃体牵引,6眼有完全PVD。巨大裂孔中2眼无明显PVD,大量皮质在裂孔中;1眼后缘有明显牵引。结论 应用超声可以诊断部分视网膜裂孔,视网膜裂孔周围多有玻璃体牵引,手术时应特别注意对此部位的处理,超声诊断对于视网膜脱离术前检查有帮助和补充的作用。     

视网膜分支静脉阻塞伴视网膜脱离16例的手术治疗

目的：分析视网膜分支静脉阻塞伴视网膜脱离患的手术治疗效果及影响因素。方法：回顾性分析视网膜分支静脉阻塞伴视网膜脱离患16例16眼的手术治疗效果及影响因素，随访6～18mo，观察视力、眼底及视网膜复位情况。结果：视网膜分支静脉阻塞以颞侧分支静脉为主；视网膜裂孔为圆形及马蹄形，均位于牵引点附近，沿血管分布。随访结束后，所有患视网膜均复位，14眼(88％)视力明显改善，2眼(12％)视力保持不变。视力预后与视网膜裂孔种类、玻璃体后脱离、视网膜新生血管及黄斑部是否脱离密切相关。结论：及时进行视网膜脱离复位及激光光凝术是治疗视网膜分支静脉阻塞伴视网膜脱离的有效方法。     

全氟癸烷液体在超过180°裂孔性视网膜脱离手术中应用

为评价全氟癸烷液体联合眼内氩激光光凝在超过１８０°巨大裂孔性视网膜脱离手术中的应用效果。采用环扎、玻璃体切除、膜剥离，部份病人联合视网膜切开或切除，术中注入全氟癸烷液体（Ｃ１０Ｆ１８），压平视网膜，展平视网膜瓣，同时应用眼内氩激光封闭视网膜裂孔，眼内充填硅油。共治疗了１０例１０眼巨大裂孔性视网膜脱离，其中裂孔超过１８０°者７眼，超过２７０°者３眼，经９～２３个月随访，９眼完全复位，１眼部份复位。术后最佳视力≥００５者５眼（５／１０）。全氟癸烷在玻璃体手术中的应用，治疗超过１８０°巨大裂孔性视网膜脱离，具有操作简便，并发症少，手术成功率高，平复视网膜后瓣，驱赶视网膜下液，便于进行增殖膜清除，以及直视下眼内氩激光封闭裂孔，不必于后极部做视网膜切开放液等优点。视网膜活动度恢复良好者，全氟癸烷注入量可超过裂孔缘，使其恢复原位。眼内注入全氟癸烷液体后宜采用硅油重水交换方式，充填硅油。     

Transplanted sheets of human retina and retinal pigment epithelium develop normally in nude rats

This study investigated whether transplanted sheets of human fetal retina together with its retinal pigment epithelium (RPE) could develop and maintain their cytoarchitecture after long survival times. Transplant recipients were nine albino athymic nu/nu rats with a normal retina. The donor tissue was dissected from fetuses of 12-17 weeks gestational age. Transplants were analyzed at 5-12 months after surgery by light and electron microscopy, and immunohistochemistry with various antibodies specific for rhodopsin, S-antigen, transducin, neurofilament and synaptophysin. In 4 of 11 transplants, the RPE stayed as a monolayer sheet and supported the development of the retinal sheet with a normal lamination, including photoreceptor inner and outer segments. Cones and rods in the organized transplants were labeled with different photoreceptor markers. Inner and outer plexiform layers, containing cone pedicles and rods spherules, were immunoreactive for synaptophysin. As the recipients had a normal retina, transplant/host integration was not expected. However, at the transplant/host interface, there were sometimes areas without glial barriers, and neurofilament-containing processes could be observed crossing between transplant and host. In other, more disorganized transplants, the RPE cells were partially dispersed or clumped together in clusters. Such transplants developed photoreceptors in rosettes, often with inner and outer segments.In conclusion, sheets of human fetal retina transplanted together with its RPE to the subretinal space of nude rats can develop and maintain perfectly laminated transplants after long survival times, indicating the potential of applying cotransplantation to human patients with retinal diseases.     

急性视网膜坏死综合征误诊分析5例

目的:急性视网膜坏死综合征是一种以中到重度葡萄膜炎、血管炎以及血管闭塞性视网膜坏死为特征的严重眼病,其早期诊断比较困难,有的甚至在行玻璃体视网膜手术过程中才被确诊。分析临床上急性视网膜坏死综合征误诊的原因,总结早期诊断的经验。方法:回顾我院5例未能及时诊断的急性视网膜坏死综合征病例的临床特点,诊治经过及最终预后,并分析误诊原因。结果:5例病例中,1例被误诊为虹膜睫状体炎,2例误诊为葡萄膜炎并视网膜脱离,1例误诊为视网膜中央动脉阻塞,1例被误诊为出血性视网膜血管炎。这些疾病在临床诊断过程中有必要考虑与急性视网膜坏死鉴别。结论:急性视网膜坏死综合征临床表现变异较大,有些表现不典型,临床工作中应充分认识此疾病。     

Management of rhegmatogenous retinal detachment without detectable breaks

Purpose: To evaluate the causes of failure to find retinal breaks, the anatomical and functional outcomes of patients with rhegmatogenous retinal detachment (RD) without detectable breaks (Group I), to compare the results with detectable breaks (Group II). Methods: Forty‐five out of 258 eyes that had RD without detectable breaks were analysed retrospectively. Results: The causes of failure to find retinal breaks were aphakia/pseudophakia in 22 eyes, small pupil without any eye disease in four eyes, corneal opacity in two eyes, cataract in two eyes, vitreous haze in two eyes, choroidal detachment in one eye, and unknown cause in 12 eyes. After a single scleral buckling procedure, anatomical re‐attachment of the retina successfully occurred in 62.2% of group I and 78.9% of group II patients. After repeated surgery, final anatomical success rates were 87.2% and 90.2%, respectively. The best corrected visual acuity was 6/60 or better in 53.9% in Group I and 52.5% in Group II. Conclusion: The main cause of failure to find the retinal break was aphakia or pseudophakia. Although the rates of retinal reattachment in eyes without detectable breaks in primary buckling surgery was lower than detectable breaks and reoperations were required more frequently, final success rates were satisfactory and similar in both groups.     

兔眼视网膜铁锈症的实验观察

在光镜和电镜下观察了25只兔眼植入铁异物1～30天的视网膜变化。结果表明,邻近铁异物的局部视网膜2天即发生变性坏死,7～30天坏死的部分由视网膜色素上皮细胞(RPE)和胶质细胞填充,形成视网膜重度萎缩。在间接铁锈症的轻度萎缩性视网膜病变中,导致感光细胞形态学改变的重要原因,可能是RPE吞噬功能异常增高。观察了RPE转变为吞噬细胞,向玻璃体侧移行的过程。     

巨大裂孔视网膜脱离手术的探讨

目的探讨玻璃体视网膜手术治疗巨大裂孔视网膜脱离的手术方法和效果。方法巨大裂孔视网膜脱离11例（11眼）。其中10眼行闭合式三通道玻璃体切除联合巩膜扣带术和眼内视网膜光凝,另1眼未做巩膜扣带。6眼手术中采用全氟化碳液（重水）-硅油置换,硅油眼内填充;5眼为气体-液体交换,硅油填充。结果 11眼手术后视网膜均完全复位。随访观察中视网膜复位良好,2眼已取出硅油。但其中1眼取出油后又发生了视网膜脱离,并出现新裂孔,又做了硅油填充术。2眼发生继发性青光眼,2眼发生了并发性白内障,其中1眼已做了白内障手术。未发生全氟化碳液（重水）眼内残留或角膜变性等并发症。结论玻璃体切除术联合巩膜扣带、硅油眼内填充、视网膜激光光凝能有效治疗有巨大裂孔的视网膜脱离。