自适应光学技术的眼科应用

自适应光学技术是一种能够实时校正光学系统随机误差并使系统始终保持良好工作性能的新技术,它在眼科领域的应用显著提高了相应检测设备的分辨率,为从细胞水平上研究活体眼底结构等提供了新的手段和工具。     

自适应光学技术在眼科的应用进展

自适应光学(AO)技术能够实时测量和校正波前像差,使光学系统能适应外界条件变化,保持良好光学性能,在眼科领域逐渐受到关注。AO技术可以根据波前像差进行验光,提高主客观验光的效率和准确性;消除人眼像差对视网膜成像的影响,为视神经功能评价提供更精准的数据;改善视知觉学习训练的效果,为特殊人群提供视力保健和治疗方法;模拟和预...     

光学相干断层成像对黄斑部视网膜手术疗效的评价

目的：探讨光学相干断层成像(optical coherence tomography，OCT)在黄斑部视网膜手术疗效评价中的作用。方法：应用OCT检查35例35只眼行黄斑部视网膜手术的患者，其中特发性黄斑裂孔23例23只眼，黄斑前膜12例12只眼。于术前和术后2～4周，分别对黄斑裂孔和黄斑前膜形态进行观察，测量裂孔直径、晕轮直径、孔缘厚度。结果：OCT显示黄斑裂孔术后裂孔直径、晕轮直径和孔缘厚度均明显缩小。黄斑前膜术后视网膜厚度在术后2周与术前对比，无显著性差异；术后4周与术前有显著性差异。结论：OCT可定量客观地提供黄斑病变形态学特征，在黄斑部视网膜手术疗效的评价上具有不可替代的作用。     

光学相干断层扫描血管成像在眼科的应用进展

光学相干断层扫描血管成像(OCTA)是近年逐渐兴起的一种眼科非入侵式影像学检查方法,它是在光学相干断层扫描(OCT)的基础上逐渐发展起来并逐步应用于临床。OCTA通过扫描血管内流动的红细胞显示出眼底血流密度与眼底组织结构形态,在眼科相关疾病(尤其是眼底病变)的诊治及疗效评估方面具有很高的价值。OCTA具有高分辨率、易操作、快速扫描、三维成像等优势,现已被应用于眼科疾病(脉络膜新生血管、糖尿病视网膜病变、角膜和虹膜相关疾病、弱视、青光眼等)的评估和诊断。本文就OCTA技术在眼科疾病中的应用进行综述。     

光学相干断层扫描血管成像技术在糖尿病视网膜病变中的应用

光学相干断层扫描血管成像技术( optical coherence tomography angiography,OCTA)是近年来光学相干断层扫描( optical coherence tomography,OCT)的新兴技术,是一种无创、快速、高分辨率的眼底血管成像技术,现已被逐渐应用于各类眼底血管疾病的诊治及随访,如糖尿病视网膜病变、脉络膜新生血管等。 OCTA拥有能分层观察不同层面的视网膜脉络膜血管结构及形态和量化一定范围内的血流指数及病灶血流面积的独特优势。但OCTA存在观察视网膜范围有限、观察视网膜血管屏障功能有限、要求高固视力高配合度等不足,如果克服这些局限,将有助于我们提升对视网膜血管疾病的认识,完善对视网膜血管疾病的诊治和观察。     

自适应光学眼底成像对临床前期羟氯喹性视网膜病变的研究

目的应用自适应光学(AO)眼底成像评估羟氯喹(HCQ)性视网膜病变临床前期患者视锥细胞的改变。方法回顾性病例对照研究。2020年5～7月于解放军总医院海南医院风湿免疫科就诊的风湿免疫性疾病患者46例(病例组)纳入研究。患者均有HCQ用药史且眼底检查未见明显异常。选取同期人口学特征匹配的健康志愿者105名作为对照组。受检者均行最佳矫正视力(BCVA)、频域光相干断层扫描(SD-OCT)、眼底自身荧光(FAF)、视野、角膜内皮镜检查以及眼轴长度(AL)测量。BCVA检查采用Snellen视力表进行, 统计时换算为最小分辨角对数(logMAR)视力。病例组46例中, 男性6例, 女性40例;年龄(42.02±13.81)岁;logMAR BCVA 0.063±0.015;AL(23.95±0.726)mm。视野、黄斑SD-OCT、FAF检查未见异常。HCQ平均累积剂量为522.60(6～1 728)g。采用rtx1 AO视网膜照相机采集受检者双眼距离中心凹3°离心率的视网膜上方、鼻侧、下方、颞侧四个象限的眼底图像。测量4个象限中视锥细胞密度、间距、排列规则度和与之相邻的距离最近的视锥细胞个数...     

重视自适应光学OCT的工程技术研究及转化应用

自适应光学相干断层扫描（AO-OCT）在2003年首次报道并取得了巨大技术进步,较传统OCT具有更好的成像能力,能获得接近人眼衍射极限的眼底视网膜微结构的高分辨率立体图像,为眼科领域提供了一种新的诊断和研究工具。笔者就AO-OCT的主要工程技术研究及转化应用做一评述,以期加深对AO-OCT重要性的认识。     

光学相干断层扫描在眼底疾病中的应用与进展

作为一种无创性的眼科临床诊断技术,光学相干断层扫描(optical coherence tomography,OCT)在视网膜疾病诊断中发挥着重要的作用。随着OCT从时域时代进入到频域时代,高速扫描和高分辨率的OCT为视网膜的分层识别带来了巨大的进展,而随着深度成像OCT的发展,很多以往不能成像的眼组织深层结构也得以观察。在未来的发展中,OCT的分辨率和穿透力将进一步提升,而功能性OCT,如多普勒OCT的出现,也将使OCT在现代眼科诊断中发挥更加重要的作用。     

应用三维光学相干断层成像术测量正常人黄斑视网膜厚度

目的 利用三维光学相干断层成像术(3D optical coherence Tomography 3D-OCT)测量正常人黄斑区视网膜厚度,观察其与性别的相关性.方法 依据早期糖尿病视网膜病变研究组(Early Treatment Diabetic Retinopathy Study ETDRS)9分区,应用3D扫描测量226名6个年龄组正常人黄斑区视网膜厚度地形图并进行统计学分析.结果 正常人黄斑中心凹平均视网膜厚度为(220±14)μm,其中男性(225±13) μm与女性(214±12)μm的差异具有统计学意义(P＜0.05).内环(1～3 mm直径区域即黄斑中心区)内鼻侧扇形区N1区平均视网膜厚度为(303±13) μm,上方扇形区S1区平均视网膜厚度为(300±11) μm,下方扇形区I1区平均视网膜厚度为(295±13) μm,颞侧扇形区T1区平均视网膜厚度为(289±12) μm.外环(3～6 mm直径区域内)鼻侧扇形区N2区平均视网膜厚度为(284±14) μm,上方扇形区S2区平均视网膜厚度为(267±12) μm,下方扇形区I2区平均视网膜厚度为(258±12) μm,颞侧扇形区T2区平均视网膜厚度为(257±11) μm.内环和外环男女差异均具有统计学意义(P＜0.05).结论 正常人经3D-OCT测得的黄斑区视网膜厚度男女之间差异具有统计学意义,在分析黄斑视网膜厚度时应考虑性别差异.     

光学相干断层扫描血管成像在糖尿病性视网膜病变临床应用研究进展

光学相干断层扫描血管成像(optical coherence tomography angiography, OCTA)作为一项近年来兴起的新型成像技术,具有非侵入性、快速、高分辨率等特点。相比于传统的造影检查,OCTA更加快速、安全且避免了传统造影剂带来的副作用和风险。如今OCTA已经逐渐应用于眼科疾病的诊疗与随访。通过对视网膜脉络膜血管的实时成像,可以用于观察疾病如糖尿病视网膜病变、脉络膜新生血管等的进展。本文就OCTA在糖尿病视网膜病变的临床应用研究进展进行综述。     

RetcanⅡ广域视网膜成像系统在小儿眼底病变筛查中的应用

目的:探讨小儿视网膜病变的检查方法和可行性。方法:回顾总结我院采用间接眼底镜及RetcanⅡ广域视网膜成像系统检查的1594例小儿眼底病变的情况。其中男825例,女769例,年龄28d~3岁,平均4mo,早产儿1314例(82.43%),足月儿280例(17.57%)。常规用美多丽扩瞳后采用RetcanⅡ广域视网膜成像系统进行检查。结果:患儿1594例中筛查出339例眼底异常。异常检出率为21.27%,其中早产儿视网膜病变200例(12.55%),视网膜出血88例,白内障3例,牵牛花综合征5例,视网膜母细胞瘤5例,视网膜渗出性改变64例,视神经萎缩8例。结论:RetcanⅡ具有宽视野即时成像图像真实清晰易保存的特点,是小儿眼底病尤其是早产儿视网膜病变筛查的安全有效可靠的方法。儿童眼底病危害大,发病率高,应重视早期筛查,以便早期干预和治疗。     

Imaging retinal mosaics in the living eye

Adaptive optics imaging of cone photoreceptors has provided unique insight into the structure and function of the human visual system and has become an important tool for both basic scientists and clinicians. Recent advances in adaptive optics retinal imaging instrumentation and methodology have allowed us to expand beyond cone imaging. Multi-wavelength and fluorescence imaging methods with adaptive optics have allowed multiple retinal cell types to be imaged simultaneously. These new methods have recently revealed rod photoreceptors, retinal pigment epithelium (RPE) cells, and the smallest retinal blood vessels. Fluorescence imaging coupled with adaptive optics has been used to examine ganglion cells in living primates. Two-photon imaging combined with adaptive optics can evaluate photoreceptor function non-invasively in the living primate retina.     

Air tamponade in retinal detachment surgery followed by ultra-widefield fundus imaging system

AIM: To report the surgical result of pars plana vitrectomy (PPV) with air tamponade for rhegmatogenous retinal detachment (RRD) by ultra-widefield fundus imaging system. METHODS: Of 25 consecutive patients (25 eyes) with fresh primary RRD and causative retinal break and vitreous traction were presented. All the patients underwent PPV with air tamponade. Visual acuity (VA) was examined postoperatively and images were captured by ultra-widefield scanning laser ophthalmoscope system (Optos). RESULTS: Initial reattachment was achieved in 25 cases (100%). The air volume was >60% on the postoperative day (POD) 1. The ultra-widefield images showed that the retina was reattached in all air-filled eyes postoperatively. The retinal break and laser burns in the superior were detected in 22 of 25 eyes (88%). A missed retinal hole was found under intravitreal air bubble in 1 case (4%). The air volume was range from 40% to 60% on POD 3. A double-layered image was seen in 25 of 25 eyes with intravitreal gas. Retinal breaks and laser burns around were seen in the intravitreal air. On POD 7, small bubble without effect was seen in 6 cases (24%) and bubble was completely disappeared in 4 cases (16%). Small oval bubble in the superior area was observed in 15 cases (60%). There were no missed and new retinal breaks and no retinal detachment in all cases on the POD 14 and 1mo and last follow-up. Air disappeared completely on a mean of 9.84d postoperatively. The mean final postoperative best-corrected visual acuity (BCVA) was 0.35 logMAR. Mean final postoperative BCVA improved significantly relative to mean preoperative (P<0.05). Final VA of 0.3 logMAR or better was seen in 13 eyes. CONCLUSION: PPV with air tamponade is an effective management for fresh RRD with superior retinal breaks. The ultra-widefield fundus imaging can detect postoperative retinal breaks in air-filled eyes. It would be a useful facility for follow-up after PPV with air tamponade. Facedown position and acquired visual rehabilitation may be shorten.     

Missed retinal breaks in rhegmatogenous retinal detachment

AIM: To evaluate the causes and associations of missed retinal breaks (MRBs) and posterior vitreous detachment (PVD) in patients with rhegmatogenous retinal detachment (RRD). METHODS: Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS: Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033) with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR) and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION: Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.     

Merits of multicolor imaging for tractional retinal detachment

Purpose:To compare multicolor imaging (MCI) with Optos color fundus photography (OCFP) for the evaluation of morphology and extent of preretinal membranes in diabetic tractional retinal detachments (TRD).Methods:In this retrospective study, 30 eyes with diabetic TRDs were imaged using the MCI feature of the Heidelberg Spectralis Spectral-domain optical coherence tomography (SD-OCT) and color photo using the Optos Daytona ultra-widefield fundus camera. Two investigators independently graded and determined the agreeability between the two modalities with respect to the extent of the TRD and preretinal membranes on the SD-OCT B-scan images.Results:The MCI provided better visualization of the attachments and traction points of the posterior hyaloid face and preretinal membranes and is comparable to the SD-OCT B-scan images. The inter-rater agreeability rates for OCFP had a Kappa (κ) value of 0.37, while the MCI had a κ value of 0.46. When comparing between images of different wavelengths, grading using infrared reflectance (IR) had a poor agreement (−0.04 ± 0.04) while green reflectance (GR) (0.46 ± 0.32) and blue reflectance (BR) (0.53 ± 0.19) had a moderate agreement. The composite MCI and GR images also had comparatively higher intraclass coefficient when compared to the OCFP (0.25 [−0.09–0.55]) and IR (−0.03 [−0.39–0.34]) images.Conclusion:MCI is more sensitive for determining the extent of TRDs and for the detection of secondary membranes when compared to OCFP, thus, aiding in better surgical planning.     

Adaptive optics scanning laser ophthalmoscopy in fundus imaging, a review and update

Adaptive optics scanning laser ophthalmoscopy (AO-SLO) has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics (AO) and AO-SLO. Then it compares AO-SLO with conventional imaging methods (fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography) and other AO techniques (adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherence tomography). Furthermore, an update of current research situation in AO-SLO is made based on different fundus structures as photoreceptors (cones and rods), fundus vessels, retinal pigment epithelium layer, retinal nerve fiber layer, ganglion cell layer and lamina cribrosa. Finally, this review indicates possible research directions of AO-SLO in future.     

In Vivo High-Resolution Retinal Imaging Using Adaptive Optics

Retinal imaging with conventional methods is only able to overcome the lowest order of aberration, defocus and astigmatism. The human eye is fraught with higher order of aberrations. Since we are forced to use the human optical system in retinal imaging, the images are degraded. In addition, all of these distortions are constantly changing due to head/eye movement and change in accommodation. Adaptive optics is a promising technology introduced in the field of ophthalmology to measure and compensate for these aberrations. High-resolution obtained by adaptive optics enables us to view and image the retinal photoreceptors, retina pigment epithelium, and identification of cone subclasses in vivo. In this review we will be discussing the basic technology of adaptive optics and hardware requirement in addition to clinical applications of such technology.     

Update on wide- and ultra-widefield retinal imaging

The peripheral retina is the site of pathology in many ocular diseases and ultra-widefield (UWF) imaging is one of the new technologies available to ophthalmologists to manage some of these diseases. Currently, there are several imaging systems used in practice for the purpose of diagnostic, monitoring disease progression or response to therapy, and telemedicine. These include modalities for both adults and pediatric patients. The current systems are capable of producing wide- and UWF color fundus photographs, fluorescein and indocyanine green angiograms, and autofluorescence images. Using this technology, important clinical observations have been made in diseases such as diabetic retinopathy, uveitides, retinal vascular occlusions and tumors, intraocular tumors, retinopathy of prematurity, and age-related macular degeneration. Widefield imaging offers excellent postoperative documentation of retinal detachment surgery. New applications will soon be available to integrate this technology into large volume routine clinical practice.     

超广角荧光素眼底血管造影在视网膜分支静脉阻塞诊治中的应用

目的　评价超广角荧光素眼底血管造影（fundus fluorescein angiography,FFA）在视网膜分支静脉阻塞诊断、治疗中的指导价值。方法　回顾分析40例（41眼）视网膜分支静脉阻塞确诊患者的传统FFA和超广角FFA资料。所有患者造影检查的早中期均行传统FFA,晚期均行欧堡超广角FFA。分析比较2种检查的视网膜可视范围、视网膜无灌注区面积、视网膜所需激光面积。结果　与传统FFA图像比较,超广角FFA检查图像所显示的视网膜可视面积以及视网膜无灌注区面积、所需激光面积分别是前者的2.03倍、1.57倍、1.96倍（均为P<0.01）。未行激光治疗的27眼中22眼有无灌注区,其中同时合并黄斑水肿者15眼,这15眼中无灌注区在赤道部以前者14眼;已行激光治疗的14眼中9眼存在黄斑水肿的表现,9眼中7眼合并无灌注区,其中6眼的无灌注区在赤道部以前。结论　超广角FFA使可观测病变检查范围扩大到远周边,对视网膜分支静脉阻塞的诊断和治疗提供更多帮助。