Update on imaging techniques in oculoplastics

Imaging is a beneficial aid to the oculoplastic surgeon especially in orbital and lacrimal disorders when the pathology is not visible from outside. It is a powerful tool that may be benefited in not only diagnosis but also management and follow-up. The most common imaging modalities required are CT and MRI, with CT being more frequently ordered by oculoplastic surgeons. Improvements in technology enabled the acquisition times to shorten incredibly. Radiologists can now obtain images with superb resolution, and isolate the site and tissue of interest from other structures with special techniques. Better contrast agents and 3D imaging capabilities make complicated cases easier to identify. Color Doppler imaging is becoming more popular both for research and clinical purposes. Magnetic resonance angiography (MRA) added so much to the vascular system imaging recently. Although angiography is still the gold standard, new software and techniques rendered MRA as valuable as angiography in most circumstances. Stereotactic navigation, although in use for a long time, recently became the focus of interest for the oculoplastic surgeon especially in orbital decompressions. Improvements in radiology and nuclear medicine techniques of lacrimal drainage system imaging provided more detailed analysis of the system.     

Lasers in oculoplastics

In the past year, there have been many important advances in laser application in not only oculoplastics but also related fields such as dermatology and plastic surgery. This review article highlights advances in laser assisted lacrimal surgery with the adjunctive use of mitomycin C and the treatment of capillary hemangiomata with a tunable dye laser. There also have been advances in laser skin resurfacing, such as the combination of carbon dioxide and erbium:yttrium-aluminum-garnet lasers to achieve improved results as well as the use of nonablative lasers. Lastly, physicians have achieved a greater understanding of the benefits and complications of combining laser resurfacing with other aesthetic procedures, such as lower blepharoplasty and facelifting.     

Review: the value of radiosurgery in oculoplastics

PURPOSE: To present the value of radiosurgery in oculoplastic procedures. METHODS: My experience of 3 years and approximately 1000 oculoplastic procedures using radiosurgery was synthesized. The radiosurgical techniques that I have found useful are presented. CONCLUSIONS: Radiosurgery is an excellent surgical tool for performing oculoplastic procedures because it coagulates blood vessels as it cuts through tissue. This allows less bleeding during surgery, which translates in better visualization of the tissue planes and a more rapid procedure.     

Advances in anterior segment imaging

PURPOSE OF REVIEW: Imaging of the crystalline lens and intraocular lens is becoming increasingly more important to optimize the refractive outcome of cataract surgery, to detect and manage complications and to ascertain advanced intraocular lens performance. This review examines recent advances in anterior segment imaging. RECENT FINDINGS: The main techniques used for imaging the anterior segment are slit-lamp biomicroscopy, ultrasound biomicroscopy, scheimpflug imaging, phakometry, optical coherence tomography and magnetic resonance imaging. They have principally been applied to the assessment of intraocular lens centration, tilt, position relative to the iris and movement with ciliary body contraction. SUMMARY: Despite the advances in anterior chamber imaging technology, there is still the need for a clinical, high-resolution, true anatomical, noninvasive technique to image behind the peripheral iris.     

Advances in retinal ganglion cell imaging

Glaucoma is one of the leading causes of blindness worldwide and will affect 79.6 million people worldwide by 2020. It is caused by the progressive loss of retinal ganglion cells (RGCs), predominantly via apoptosis, within the retinal nerve fibre layer and the corresponding loss of axons of the optic nerve head. One of its most devastating features is its late diagnosis and the resulting irreversible visual loss that is often predictable. Current diagnostic tools require significant RGC or functional visual field loss before the threshold for detection of glaucoma may be reached. To propel the efficacy of therapeutics in glaucoma, an earlier diagnostic tool is required. Recent advances in retinal imaging, including optical coherence tomography, confocal scanning laser ophthalmoscopy, and adaptive optics, have propelled both glaucoma research and clinical diagnostics and therapeutics. However, an ideal imaging technique to diagnose and monitor glaucoma would image RGCs non-invasively with high specificity and sensitivity in vivo. It may confirm the presence of healthy RGCs, such as in transgenic models or retrograde labelling, or detect subtle changes in the number of unhealthy or apoptotic RGCs, such as detection of apoptosing retinal cells (DARC). Although many of these advances have not yet been introduced to the clinical arena, their successes in animal studies are enthralling. This review will illustrate the challenges of imaging RGCs, the main retinal imaging modalities, the in vivo techniques to augment these as specific RGC-imaging tools and their potential for translation to the glaucoma clinic.     

几种新型眼前节影像技术及临床应用

以眼前节光学相干断层扫描（OCT）、Scheimpflug技术、高分辨率磁共振成像及裂隙扫描等为代表的眼前节影像技术提供了房角的各种参数,可测量角膜前后表面的曲率和前房内径,计算出角膜的屈光度,在准分子激光角膜原位磨镶术（LASIK）术后能够测量角膜瓣厚度,甚至可用于调节功能及老视的研究,极大地提高了诊疗水平。就几种新型眼前节影像技术的研究进展及其临床应用进行综述。     

年龄相关性黄斑变性的影像学研究进展

年龄相关性黄斑变性(age-related macular degeneration,AMD)是发达国家50岁以上人群致盲的首要原因.近年来,随着影像学技术在眼科的应用和发展,对该病的发病机制、诊断水平及疗效评价能力大大提高.本文将就近年来AMD的影像学研究进展予以综述.     

Advances in magnetic resonance imaging of orbital disease

Magnetic resonance imaging (MRI) is increasingly used by the orbital surgeon to aid in the diagnosis, surgical planning, and monitoring of orbital disease. MRI provides superior soft tissue detail compared with computed tomography or ultrasound, and advancing techniques enhance its ability to highlight abnormal orbital pathology. Diffusion-weighted imaging is a specialized technique that uses water molecule diffusion patterns in tissue to generate contrast signals and can help distinguish malignant from benign lesions. Steady-state free precession sequences such as Constructive Interference in Steady-State (CISS) and Fast Imaging Employing Steady-state Acquisition (FIESTA) generate highly detailed, 3-dimensional reconstructed images and are particularly useful in distinguishing structures adjacent to cerebral spinal fluid. Magnetic resonance angiography can be used to characterize vascular lesions within the orbit. New developments in magnetic field strength as well as the use of orbital surface coils achieve increasingly improved imaging resolution.     

眼内肿瘤的影像学诊断进展

眼内肿瘤的早期诊断及正确治疗是决定预后的重要因素.间接眼底镜检查结合影像学检查是诊断和鉴别诊断的重要手段,近年来眼内肿瘤的影像学诊断技术不断发展,为眼内肿瘤的诊疗提供了更有利的支持.     

眼前节成像与生物测量分析系统的最新进展

眼前节成像和生物测量分析系统广泛应用于眼前节疾病的诊断、白内障屈光手术的临床观察、眼前节结构生物参数的测量等.目前国内外许多仪器均能客观地对眼前节进行成像和生物测量,如裂隙灯生物显微镜、超声生物显微镜、光学相干断层扫描等.本次我们就各种最新的眼前节成像和生物测量仪器的原理、各自的特点及其在眼科领域的应用进行综述.     

Advances in retinal imaging for diabetic retinopathy and diabetic macular edema

Diabetic retinopathy and diabetic macular edema (DME) are leading causes of blindness throughout the world, and cause significant visual morbidity. Ocular imaging has played a significant role in the management of diabetic eye disease, and the advent of advanced imaging modalities will be of great value as our understanding of diabetic eye diseases increase, and the management options become increasingly varied and complex. Color fundus photography has established roles in screening for diabetic eye disease, early detection of progression, and monitoring of treatment response. Fluorescein angiography (FA) detects areas of capillary nonperfusion, as well as leakage from both microaneurysms and neovascularization. Recent advances in retinal imaging modalities complement traditional fundus photography and provide invaluable new information for clinicians. Ultra-widefield imaging, which can be used to produce both color fundus photographs and FAs, now allows unprecedented views of the posterior pole. The pathologies that are detected in the periphery of the retina have the potential to change the grading of disease severity, and may be of prognostic significance to disease progression. Studies have shown that peripheral ischemia may be related to the presence and severity of DME. Optical coherence tomography (OCT) provides structural detail of the retina, and the quantitative and qualitative features are useful in the monitoring of diabetic eye disease. A relatively recent innovation, OCT angiography, produces images of the fine blood vessels at the macula and optic disc, without the need for contrast agents. This paper will review the roles of each of these imaging modalities for diabetic eye disease.     

房水流出通路结构及功能显像的研究进展

房水作为重要眼内容物之一,一直处于动态循环中,若房水流出通路(AHO)中的任一部位受阻,都将导致眼压升高,并伴随青光眼的发生,进而出现视神经损伤,严重影响视功能。而开角型青光眼患者的房角呈开放状态,其眼压升高是房水流出阻力增加所致,因此,直观地观察AHO的结构,评价其功能变化,有助于我们更清晰地了解AHO的阻力所在,进一步阐明开角型青光眼的发病机制。目前对于AHO的显像技术包括光学相干断层扫描(OCT)以及AHO造影术等。本文将就AHO结构及功能显像的研究进展做一综述。     

Advances and potential new developments in imaging techniques for posterior uveitis Part 2: invasive imaging methods

The aim of this review was to identify the imaging methods at our disposal to optimally manage posterior uveitis at the present time. The focus was put on methods that have become available since the 1990s, some 30 years after fluorescein angiography had revolutionised imaging of posterior uveitis in particular imaging of the retinal vascular structures in the 1960s. We have focussed our review on precise imaging methods that have been standardised and validated and can be used universally thanks to commercially produced and available instruments for the diagnosis and follow-up of posterior uveitis. The second part of this imaging review will deal with invasive imaging methods and in particular ocular angiography.Subject terms: Uveal diseases, Medical imaging     

Advances in imaging the blood and aqueous vessels of the ocular limbus

The vessels of the limbus play a pivotal role in the drainage of the major portion of aqueous humour from the anterior chamber. Aberrations in the limbal architecture can lead to raised intraocular pressure, which in turn can lead to blinding conditions such as glaucoma. Imaging these vessels in the normal eye, in development, and in conditions where there is anterior segment dysgenesis remains a challenge. Here we review the progress in limbal vessel imaging in the past 50 years and provide key information on their strengths and limitations. Included is an analysis of serial histological sectioning, ultrathin sections, microvascular perfusion with plastics and corrosion casting, X-ray microcomputed tomography, in vivo imaging including analysis of transgenic mice expressing GFP-vascular endothelium fusion proteins, in vivo microscopy imaging using fluorescent-labelled antibodies, slit-lamp microscopy and gonioscopy, fluorescein angiography, optical coherence tomography, and various labelling procedures for the vascular endothelium and the various forms of microscopy used to view these.