Scanning electron microscopic studies of the zonular apparatus in human and monkey eyes.

Scanning electron microscopic studies of the zonular apparatus in 10 human and 17 monkey eyes revealed two functionally different sets of zonular fibers: the "main fiber" and the "tension fiber" system. The two systems are connected, forming a broad, sagittally oriented "zonular plexus" within the pars plicata of the ciliary body. The zonular plexus is attached to the ciliary epithelium by the tension fibers, which leave the main system and run obliquely forward to the epithelium deep in the valleys of the ciliary processes. Anteriorly, the zonular plexus splits into the two branches of the "zonular fork," which run respectively to the anterior and posterior aspect of the lens. Thus the zonular plexus can act as a fulcrum. The three-dimensional architecture of the zonular apparatus is consistent with a new concept of accommodation.     

Ultrasound biomicroscopy in traumatic aniridia 2 years after phacoemulsification

A 45-year-old man with retinitis pigmentosa experienced total aniridia in the left eye due to direct blunt trauma 2 years after uneventful bilateral phacoemulsification via a 3.5 mm clear corneal incision. Ultrasound biomicroscopy (UBM) of the left eye revealed no missing or stretched zonular fibers extending from the ciliary body to the anterior capsule, a few iris root remnants, a normal ciliary body, an in-the-bag acrylic intraocular lens, and Descemet's membrane dehiscence at the corneal tunnel through which the iris extruded. The eye recovered 20/25 visual acuity after 1 week. Transient hyphema and a rise in intraocular pressure were recorded. This is the first report of traumatic aniridia 2 years after phacoemulsification with UBM evidence of undamaged zonular apparatus. A UBM examination may be clinically helpful, especially when blood prevents accurate slitlamp examination of the anterior segment.     

Ultrasound biomicroscopy of the aging rhesus monkey ciliary region.

Ultrasound biomicroscopy of the living rhesus monkey ocular ciliary region was undertaken to identify age-dependent changes that might relate to the progression of presbyopia. Monkeys were anesthetized and pharmacologically cyclopleged, the eyelids were held open with a lid speculum, and sutures were placed beneath the medial and lateral rectus muscles. Ultrasound biomicroscopy imaging of the nasal and temporal quadrants of the eye were performed, and the live images were recorded to videotape. Subsequent image analysis was performed to obtain objective morphometric measurements of the ciliary body region. The ciliary body inner radius of curvature, outer radius of curvature, inner arc length, area, thickness, perimeter, zonular fiber length, and circumlental space were measured. Zonular space was calculated. The circumlental space decreased with increasing age in the temporal quadrant. The other morphologic measurements were not significantly correlated with age or body weight. Most morphologic measurements were significantly different comparing temporal vs. nasal quadrants. Bifurcation of the posterior zonular fibers was frequently observed. Although temporal circumlental space was the only measurement found to change with age, ultrasound biomicroscopy of the living rhesus ciliary region did identify distinct nasal vs. temporal asymmetries, which may reflect anatomical requirements for convergence-associated accommodation.     

人眼睫状体在调节中形态与位置的动态变化

目的了解健康活体人眼在自发视远视近调节中,睫状体形态和位置动态变化的特点。方法利用超声生物显微镜(UBM)的50MHz高频换能器,对68例正常人眼注视远、近不同视标时睫状体形态、位置的变化进行动态观测和统计学分析。结果(1)视近调节时,睫状体前部厚度、睫状突长度、睫状体总面积和环形肌面积增大,睫状突宽度及内尖成角、睫状突与小梁、虹膜、巩膜突的距离,以及其和虹膜、巩膜的夹角减小,前房角开放程度变小。而睫状体后部厚度、纵行肌面积、巩膜虹膜夹角以及小梁虹膜夹角的差异无显著意义。(2)形态各参数间的变化相辅相成、高度一致,位置各参数亦然,但形态与位置之间关系无显著意义。结论人眼视近调节时,睫状体各部肌纤维协调收缩,尤其是环形肌收缩,使睫状突变得尖而细长,睫状体向前向内移动,松弛悬韧带,支持Helmholtz的调节松弛学说。UBM可实时观测人眼调节时睫状体各部分形态和位置等的变化情况。     

不同年龄健康人眼调节状态超声生物显微镜对比观察

目的 了解健康人眼在不同调节状态下,睫状体、晶状体形态位置动态变化的特点及其与年龄变化的关系.方法 利用超声生物显微镜(UBM),对70名不同年龄组正常人眼注视远、近不同距离视标时睫状体、晶状体形态位置的变化进行动态观察和统计学分析.结果 (1)视远时,睫状体厚度平均值(1.08±0.15)mm,睫状突长度平均值(1.92±0.29)mm, 睫状突宽度平均值(0.74±0.11)mm,晶状体中央厚度平均值(3.46±0.45)mm;视近时,睫状体厚度平均值(1.16±0.17)mm,睫状突长度平均值(2.05±0.27)mm,睫状突宽度平均值(0.67±0.09)mm,晶状体中央厚度平均值(3.57±0.42)mm;视近与视远相比,睫状体前部厚度增加、睫状突长度增加,睫状突宽度变小,晶状体中央厚度增加,各参数经独立样本t检验,P值均<0.05,差异有统计学意义.(2)随年龄增加,视远、视近时各形态参数与年龄间经Pearson检验存在相关性.结论 人眼视近时,睫状体各部肌纤维协调收缩,使睫状突变长变尖,睫状体向前向内移动,松弛悬韧带,晶状体借自身弹性变凸,中央厚度变厚,前后径增加.同时,随年龄增长,人眼调节力逐渐下降.支持Helmholtz的调节松弛学说.利用UBM可实时观察人眼调节时眼前节结构形态和位置的变化情况.     

眼挫伤后睫状体脱离的UBM观察

目的:超声生物显微镜(ultrasound biomicroscopy,UBM)观察眼挫伤后睫状体脱离的特点,并评价UBM指导下睫状体缝合手术治疗眼挫伤后睫状体脱离的临床效果。方法:应用UBM观察30例30眼因眼球挫伤导致睫状体脱离的特点,其中5例5眼行房角漏对应位置和范围的睫状体缝合复位手术,观察视力、眼压及复查UBM及B超(其余患者为门诊患者,具体治疗及预后情况不详)。结果:UBM检查示不同程度的睫状体脱离,27眼为全周睫状体脱离,26眼存在房角漏口,平均中央前房深度(1.830±0.575)mm。5眼行房角漏对应位置和范围的睫状体缝合复位手术后,所有患者房角漏口全部封闭,全周睫状体脉络膜脱离痊愈,前房加深,视力提高,眼压上升至正常。5眼中,4眼行1次手术后睫状体脉络膜脱离痊愈,1眼行4次手术后痊愈。结论:UBM是诊断眼挫伤后睫状体脱离的较好的工具,UBM指导下睫状体缝合手术治疗房角漏的临床效果好,UBM对于眼挫伤致睫状体脱离的临床诊断、治疗和随访具有指导意义。     

虹膜睫状体肿物的超声生物显微镜检查

目的 探讨超声生物显微镜（ultrasound biomicroscope, UBM）在虹膜睫状体肿物诊断治疗中的应用价值。 方法 对34例怀疑虹膜睫状体肿物的患者的35只患眼以UBM（Humphrey 840型，扫描频率50 MHz，扫描深度范围5 mm×5 mm）检查，17例行眼科专用B型超声或彩色超声检查,5例行CT检查，并对21只患眼手术切除的病变组织作病理组织学检查。 结果 35只患眼虹膜睫状体肿物可被UBM发现并确定其起始部位。其中UBM诊断前房虹膜囊肿6只眼,病理诊断虹膜植入性囊肿3只眼;UBM诊断虹膜后囊肿13例14只眼,病理诊断虹膜后囊肿3只眼;UBM诊断虹膜睫状体肿物15只眼,病理诊断睫状体黑瘤7只眼，虹膜睫状体转移癌4只眼，睫状体神经鞘瘤1只眼，平滑肌瘤1只眼，睫状体黑色素细胞瘤1只眼，色素上皮腺癌1只眼。 结论 UBM检查能发现虹膜睫状体部位的肿瘤并提供其大小、范围和结构信息，有助于了解病变的位置、性质，有助于手术设计和肿物的完全切除。 (中华眼底病杂志, 2002, 18: 128-130)     

Ultrasound biomicroscopic classification of zonules in exfoliation syndrome

PURPOSE: Exfoliation changes in the zonules or ciliary processes may be the earliest clinical sign of the exfoliation syndrome (XFS). In the present study we investigated the usefulness of ultrasound biomicroscopy (UBM) for detecting the early changes of XFS in zonules. METHODS: Both eyes of 11 patients with unilateral XFS and the unilateral eyes of 11 subjects without evidence of XFS were examined using UBM. The incidence of zonular changes was compared among the XFS-positive eyes of the patients, their contralateral XFS-negative eyes, and the healthy eyes of the subjects without XFS. RESULTS: Using UBM, we could successfully describe the zonules in all UBM images of all subjects. In the four quadrants, the incidence of granular-type zonules was statistically different among the three groups: it was higher in XFP-positive eyes than in XFS-negative eyes, and it was higher in XFS-negative eyes than in healthy eyes. CONCLUSIONS: UBM can detect the zonular changes that may occur early in XFS. A granular-type change in the zonules may be the most typical finding in the presence of exfoliation material. Diagnostic criteria are proposed for the early detection of XFS, based on the changes found in the zonules by UBM.     

Patency of superior ciliary sulcus in aphakic silicone oil-filled eyes: an ultrasound biomicroscopy study

Objective: To assess the patency of the superior ciliary sulcus in aphakic silicone oil-filled eyes by ultrasound biomicroscopy (UBM).Design: Prospective interventional series.Participants: Twelve eyes of 12 patients were included in this study.Methods: Twelve aphakic silicone oil-filled eyes were evaluated using UBM. The UBM examination of the anterior segment was performed using the Humphrey Instruments UBM equipped with a high-frequency (50 MHz), high-resolution (50 mm) transducer. The patients were placed in a semisitting position in which their backs were inclined to a suitable angle (about 50°). They were also asked to look straight ahead, to bring the superior ciliary sulcus to the highest point of the globe. The probe approached the patients' eyes superiorly at a slight angle (about 10°). Images of the superior ciliary sulcus were captured and analyzed.Results: The UBM images demonstrated an intact curved aqueous-silicone oil interface that appeared at some distance from and not filling the ciliary sulcus. A patent superior ciliary sulcus was thus found in all patients, even in those with a widely opened ciliary sulcus.Conclusions: The superior ciliary sulcus maintained its patency in aphakic silicone oil-filled eyes. These findings indicate that an iridectomy in a superior position may also be effective, although this has not been tested clinically in this report.     

Ultrasound biomicroscopic features of anterior proliferative vitreoretinopathy.

PURPOSE: To evaluate the utility of ultrasound biomicroscopy (UBM) in the diagnosis of anterior proliferative vitreoretinopathy (APVR). METHODS: Ultrasound biomicroscopy (frequency, 50 MHz; depth of penetration, 5 mm; resolution, 40 microm) was used to examine 53 eyes of 52 subjects with rhegmatogenous or traumatic retinal detachment (RD). The results were compared with findings during vitrectomy. RESULTS: In 43 eyes (42 patients), RD was detected using UBM, attaining 81% consistency with observations during operation. Among 36 eyes with surgically proved APVR, 33 (92%) had APVR detected by UBM. The UBM images showed shallow RD, circumferential contraction, or anterior displacement around the ora serrata. The anterior displacement could be classified into C-shaped anterior displacement, ciliary body adhesion, and pupil adhesion. Ultrasound biomicroscopy showed that a retinal step was formed on the surface of the ora serrata and the ciliary body. Failure to detect APVR by UBM may be due to severe choroidal detachment or a narrow palpebral fissure that hampers exposure of the ora serrata and the part of the eyeball posterior to it. CONCLUSION: Ultrasound biomicroscopy is a useful tool for the evaluation of APVR, which is difficult by ordinary methods. Ultrasound biomicroscopic images of APVR have typical features that may be used to help guide surgery and estimate prognosis.     

Typical ultrasound biomicroscopic findings seen in ocular hypotony

Detailed imaging of the ciliary body region by means of ultrasound biomicroscopy can provide information that is crucial for further treatment whereas clinical evaluation and 10-MHz standard B scan are less helpful. BACKGROUND: To evaluate the suitability of ultrasound biomicroscopy (UBM) for elucidating the causes of ocular hypotony. PATIENTS AND METHODS: A retrospective chart review was performed to determine the usefulness of UBM in the evaluation of ocular hypotony. UBM, B scan, and a detailed clinical examination had been performed. Sixty patient charts with prolonged ocular hypotony of different causes were reviewed from January 1994 to December 1998. The information obtained by the UBM was classified into three groups: 'diagnostic' (group 1), 'helpful' (group 2), 'not helpful' (group 3). RESULTS: Of the 60 eyes, 45 UBM examinations (75%) were in group 1, 9 eyes (15%) were assigned to group 2 and 6 eyes (10%) were in group 3. The duration of hypotony had no influence. CONCLUSION: In cases of ocular hypotony, the cause was related to ciliary body pathologies in 80%. Only UBM could distinguish tractional from dehiscence ciliary body detachment which required a different management approach. UBM with its high resolution imaging of the anterior segment - including the ciliary body - is highly suitable for diagnostic clarification.     

Monitoring accommodative ciliary muscle function using three-dimensional ultrasound

BACKGROUND: Our objective was to develop a three-dimensional high-resolution ultrasonic imaging technique to be utilized for in-vivo characterization of the ciliary body and the posterior iris. The benefit of this imaging in enhancing the quantification of the configurational changes in the ciliary body during accommodation is demonstrated. METHODS: Sequential ultrasound biomicroscopic images of the ciliary body region were obtained with a computer-controlled scanning device designed for use with a standard ultrasound biomicroscope for 3D imaging. Custom-made software allows online data collection, data analysis and 3D reconstruction in conjunction with commercially available VoxelView software. RESULTS: The three-dimensional presentation allows a close approximation of the ciliary muscle inside the ciliary body in vivo. We are able to distinguish and to analyze the changes in the muscle contour in different accommodation states. During accommodation a shift in the ciliary muscle center of gravity in a range of 0.04-0.26 mm (mean 0.13+/-0.06 mm) in the direction of the lens equator, with an interindividual variation and a small decrease with age, was observed. CONCLUSIONS: High-resolution ultrasound is a well established technique for in-vivo investigation of the anterior segment. Three-dimensional ultrasound biomicroscopy allows an assessment of the individual ciliary muscle activity in consideration of the ciliary processes. In combination with a contour analysis tool we improved the muscle contour determination during different accommodation states. The investigation showed an activity of the ciliary muscle in young volunteers as well as those of presbyopic age.     

原发性先天性青光眼眼前段活体结构观察

目的:观察先天性青光眼的超声生物显微镜(UBM)图像特征并探讨先天性青光眼的发病机制。方法:采用高频、高分辨率的超声生物显微镜对6例先天性青光眼患者10只眼的房角、虹膜、睫状体等进行扫描和分析,并与7例正常人或无相关疾病患者的7只眼进行比较。结果:超声生物显微镜检查显示出原发性先天性青光眼的房角、虹膜、睫状体及巩膜突发育不良,虹膜基质薄,睫状体细小,巩膜突解剖特征不明显。原发性先天性青光眼组的虹膜厚度及睫状体大小的测量和统计学比较均明显小于正常对照组。结论:超声生物显微镜可以观察到常规眼科检查观察不到的部位,如睫状体、房角隐窝、虹膜后表面等等。原发性先天性青光眼具有虹膜基质薄、睫状体细小、巩膜突解剖特征不明显等特征,提示原发性先天性青光眼除了房角发育异常外,尚合并存在虹膜、睫状体巩膜突发育不良。其中虹膜、睫状体发育不良可能是先天性青光眼相对比较重要的发病机制。眼科学报1998;14:83—86。     

超声生物显微镜(UBM)在青光眼诊断分型中的作用

目的：探讨超声生物显微镜在青光眼疾病临床分型诊断中的价值。方法：对临床上拟诊为青光眼的患者行视野、房角镜、UBM检查。结果：1．部分临床上诊断原发性闭角青光眼的患者行UBM检查显示睫状体囊肿的存在，睫状体前移，造成房角关闭，是继发青光眼范畴。2．UBM发现高褶虹膜型青光眼的特殊前房及房角形态。结论：UBM在青光眼疾病临床诊断分型中有一定的指导性和实用性，是一种新的客观检测方法。     

Functional morphology of accommodation in the raccoon

The raccoon (Procyon lotor) is a small carnivore which eats in the upright position, using hand- and finger-like front paws and digits to wash, hold and examine its food at close range. These anatomic and behavioral characteristics prompted structural and functional studies of the accommodative capability of this species. By light and electron microscopy, we observed a prominent ciliary smooth muscle and zonular apparatus. When stimulated by carbachol or pilocarpine, the muscle and zonular apparatus exhibited a shift from longitudinal to reticular or circular orientation of some ciliary muscle bundles, anterior movement of the muscle as a whole, and more oblique crossing of the zonular fiber bundles in the zonular plexus. Maximum carbachol-induced accommodative amplitude measured by coincidence refractometry ranged from 3 to 19 diopters in these 1 to 9 yr old animals, with no definite age-accommodation relationship. A-scan ultrasonographic biometry showed that during accommodation the lens thickened very little, if at all, but moved anteriorly, while the apparent cornea to retina distance increased slightly. The raccoon thus exhibits the greatest accommodative capability of any non-primate terrestrial mammal so far studied.     

Buphthalmia secondary to congenital pigmented epithelial iris cyst

We report the case of a 2-day-old child with buphthalmia caused by a congenital pigmented epithelial iris cyst. The use of ultrasound biomicroscopy (UBM) and high-resolution echography (20MHz) specified the diagnosis before general anesthesia for complete examination and treatment. Surgery can control intraocular pressure and the opening of the visual axis; there is, however, relative amblyopia. This case confirms the advantage of UBM in examining tumors of the anterior segment. The early diagnosis, facilitated by use of the UBM, provided quick and well-adapted treatment.     

High-resolution ultrasound imaging of the eye – a review

This report summarizes the physics, technology and clinical application of ultrasound biomicroscopy (UBM) of the eye, in which frequencies of 35 MHz and above provide over a threefold improvement in resolution compared with conventional ophthalmic ultrasound systems. UBM allows imaging of anatomy and pathology involving the anterior segment, including regions obscured by overlying optically opaque anatomic or pathologic structures. UBM provides diagnostically significant information in conditions such as glaucoma, cysts and neoplasms, trauma and foreign bodies. UBM also can provide crucial biometric information regarding anterior segment structures, including the cornea and its constituent layers and the anterior and posterior chambers. Although UBM has now been in use for over 15 years, new technologies, including transducer arrays, pulse encoding and combination of ultrasound with light, offer the potential for significant advances in high-resolution diagnostic imaging of the eye.     

Comparison of 25 MHz and 50 MHz ultrasound biomicroscopy for imaging of the lens and its related diseases

AIM: To compare the results of 25 MHz and 50 MHz ultrasound biomicroscopy (UBM) regarding the image characteristics of the lens and its related diseases and to discuss the application value of 25 MHz UBM in ophthalmology. METHODS: A total of 302 patients (455 eyes) were included in this study from November 2014 to May 2015. Patient ages ranged from 5 to 89y (mean±SD: 61.0±17.7y). Different cross-sectional images of the lens were collected to compare and analyze the image characteristics and anterior segment parameters using 25 MHz and 50 MHz UBM in axial and longitudinal scanning modes, respectively. SPSS 19.0 for Windows, paired t-tests and B&A plot analysis were used for data analysis, and a value of P<0.05 was considered statistically significant. RESULTS: The 25 MHz UBM images displayed the lens shape more clearly than 50 MHz UBM images. Particularly for cataracts, the whole opacity of the lens was shown by 25 MHz UBM, but 50 MHz UBM only showed part of the lens. The means of the anterior segment parameters obtained using 25 MHz and 50 MHz UBM were as follows: central corneal thickness: 0.55±0.03 and 0.51±0.04 mm, respectively; central anterior chamber depth: 2.48±0.54 and 2.56±0.56 mm, respectively; and central lens thickness: 4.26±0.62 and 4.15±0.56 mm, respectively. A statistically significant difference was found between the results obtained with 25 MHz UBM and those obtained with 50 MHz UBM. The two devices had a good agreement in measuring the anterior segment parameters. CONCLUSION: The 25 MHz UBM had an obvious advantage in showing the lens shape. It can provide reliable imaging of the lens and its related diseases and has a high application value for ophthalmology.     

原发性睫状体前旋型青光眼

为探讨原发性睫状体前旋型青光眼的临床表现和UBM对此型青光眼的诊断价值。方法：选择2例经UBM确诊为睫状体前旋型青光眼患者,比较了其临床表现和UBM的形态特征,并与1例睫状体位置正常的发育性青光眼比较。结果：证实UBM检查可明确地显示睫状体前旋型青光眼的形态特征。结论：UBM对原发性睫状体前旋型青光眼有重要的鉴别诊断意义。