Ultrasound biomicroscopy pdf

Further, UBM is frequently used in research to better understand the angle and can be used for qualitative analysis of the anterior chamber angle ACA. Analysis and interpretation of images begins with identification of the scleral spur, a protrusion of the sclera into the anterior chamber that attaches anteriorly to the trabecular meshwork. UBM can describe the presence of angle closure glaucoma, which is indicated by irido-corneal contact anterior to the scleral spur.

It can also distinguish between different types of angle closure, including pupillary block, plateau iris and lens-related. Although UBM provides high quality images and a close agreement with gonioscopy, the latter remains the gold standard to diagnose narrow angle and angle closure allowing direct visualization of structures to assess the presence and extent of PAS and differentiating from iridotrabecular apposition.

Therefore, none of the current AS imaging modalities should be considered a substitution for gonioscopy, rather as a complimentary tool in glaucoma. UBM is particularly important in the diagnosis and management of ocular surface tumors. It can improve detection of invasion to adjacent structure since it is able to identify the posterior margin identification, even in densely pigmented tumors or cases with corneal opacities in anterior chamber tumors.

Optical coherence tomography OCT is a widely used imaging device in ophthalmology and has been evolving since its first publication in by Huang et al. AS-OCT can also provide quantitative measurements and is used in keratoconus diagnosis, corneal refractive surgery, corneal transplant surgery, and other ocular surface diseases including tumors. AS-OCT can also generate up to 10mm corneal diameter CT and ET maps by performing high resolution scans on 8 meridians of the cornea, with automated software that reconstructs the cornea 3-dimensionally.

Similar to other pachymetry methods i. Interestingly, changes of ET have been shown even in subclinical disease and could be a sensitive marker in early and form fruste keratoconus. The characteristic findings are significantly thick and hyperreflective epithelium in OSSN compared to benign lesions such as pterygium and Salzmann nodules, correlating to the histopathological findings.

In summary, both UBM and AS-OCT are useful non-invasive complimentary tools that show a strong correlation to histopathology with inherit advantages and disadvantages to each technique. They provide important information of intralesional features, lesion extension, size and morphology; however, more studies are warranted to determine which modality is most suitable for each tumor type.

Biopsy with histopathology remains the gold standard as it allows histologic diagnosis with cellular atypia assessment, removal of the entire lesion in excisional biopsy , evaluation of margins and tissue invasion. Create account Log in. Main Page. Getting Started. Recent changes. View form. View source. Ultrasound Biomicroscopy From EyeWiki. Jump to: navigation , search. Enroll in the Residents and Fellows contest.

Enroll in the International Ophthalmologists contest. Case summary: A year-old female was diagnosed as anterior uveitis for 1 year. Visual acuity was hand motion and IOP was 21 mm Hg. Slit lamp revealed fibrous exudation in the pupil region and the pupil was completely occluded. Case summary: A 9-year-old boy was diagnosed as persistent pupillary membrane. The diagnosis was verified by slit lamp and the observation of fundus was obscured. UBM showed a piece of residual membrane covering the entire pupil region white arrow , there was a close contact between the membrane and lens anterior capsule probably synechiae.

The existence of synechiae suggested YAG laser alone may not able to remove the membrane, attention should be paid not injury the lens if surgery is planned. This UBM image-montage shows the effect of laser iridotomy. Angles have opened after laser PI, and the bombe iris marked by white arrow in Fig. A becomes flat shown as Fig.

The iris insertion is located in the middle of the anterior face of the ciliary body, suggesting the location of iris insertion is important. Before laser PI Fig. Typical anteriorly-rotated, large ciliary body supports the peripheral iris black arrow in Fig. A , preventing the peripheral iris moving backward after laser iridotomy shown in Fig.

Anterior location of the iris insertion also plays a role in this mechanism. Anterior rotation of ciliary body, anterior iris insertion, iris thickness and configuration at insertion, all contribute to the angle-closure in those predominantly caused by non-pupil block mechanism.

Laser peripheral iridotomy only has limited efficacy in these cases. Argon laser peripheral iridoplasty may have better outcome but need further evidence to prove. PAS is a permanent adhesion between the peripheral iris and trabecular meshwork or the back of cornea. This is believed to be the anatomical basis for chronic angle closure. The mechanism of the establishment of PAS is not entirely understood. PAS is also able to extend from a localized one to all over the entire circumference of the drainage angle.

Provocative tests are intended to stimulate the physiological conditions under which angle-closure may occur. The outcome measurement, rising of IOP, is used to differentiate those with increasing risk and require further intervention.

Observation on the angle-closure after provocative test using gonioscopy could be challenging as the illumination and gonioscopy manipulation will probably open the angle. UBM can be performed in dark room and involves relatively less manipulation, thus, it is better than gonioscopy to observe the angle-closure after provocative test. The angle is obviously widened with pupil construction under light stimulation.

This test can be used to identify an appositional closed angle which is important to guide the following therapy. Neovascular glaucoma is usually secondary to retinal ischemic abnormalities, e.

Usually, IOP elevation typically results from occlusion of the drainage angle by fibrovascular membrane. Case summary: A year-old female has been diagnosed with diabetic retinopathy complicated with multiple recurrent vitreous hemorrhage for 7 years. Panretinal photocoagulation has been performed before.

Visual acuity was 0. Slit lamp examination confirmed an edematous cornea and irregular, nonradial vessels were presented in the iris stroma. Peripheral anterior chamber was absent.

UBM examination revealed the atrophy of iris stroma, anterior synechiae secondary to the contraction of the fibrovascular membrane. The drainage angle was completely closed white arrow in Fig. Figure 26B demonstrated the hyphema resulting from the breaking of neovessels asterisk. In these particular cases with corneal edema or hyphema, UBM is very useful to identify the changes of iris and angles white arrow in Fig.

Iridocorneal endothelial syndrome ICE, see other sections. Pigmentary dispersion syndrome see other sections. It was believed that the blockage of the aqueous flow at the level of ciliary body or anterior vitreous face causing malignant glaucoma. The aqueous humor is misdirected into vitreous cavity producing expansion of vitreous cavity and increase of posterior segment pressure.

Iris-lens diaphragm was forced to move forward by the high vitreous pressure. Case summary: A year-old male presented at 2nd day after trabeculectomy. Slit lamp examination found central anterior chamber was of slit width with the anterior lens surface very close to corneal endothelium, IOP was 39 mm Hg. Bleb was diffused and slightly elevated.

In Figure 27A , UBM examination revealed that the peripheral iris was closely contacted with the back of cornea white arrowhead , anterior lens surface was very close to corneal endothelium white arrow. In Figure 27B , ciliary body is compressed to become thin and long white arrow. Case summary: A 2-year-old boy was diagnosed with bilateral congenital glaucoma.

UBM revealed the typical spike-shape of the scleral spur disappeared marked by black arrow , iris is thin and loss of stroma elasticity, peripheral iris was adhered on the back of the cornea. Other developmental abnormalities of trabecular meshwork could also affect the aqueous outflow. UBM is useful in detecting the changes of drainage angles particularly in those with cloudy cornea, but a general anesthesia is required for young patients affect its usage in congenital glaucoma.

Laser iridotomy: Changes of drainage angle before and after treatment. A The iris appears bombe leading a narrow angle white arrow before LPI. B and C With a patten PI, the chamber angle is widened obviously white arrow , the bombe iris becomes flat.

Peripheral iridotomy remains the cornerstone of the management of angle closure. It results in a significant increase in the angle width by eradicating the pupil block mechanism. However, for those predominately caused by non-pupil block mechanism, peripheral iridotomy is not always effective. The following case was presented as anterior rotation of ciliary body asterisk in Fig.

After that, the patient received iridoplasty and the angle was then opened Fig. Laser cyclophotocoagulation is considered for as a safe cyclodestructive procedure for refractory glaucoma patients who have failed trabeculectomy or tube shunt procedure, or patients with minimal useful vision and uncontrolled IOP, or those being reluctant for surgery.

Transcleral and endoscopic cyclophoto-coagulation are two procedures commonly used. Accurate positioning of the laser probe is challenging in the destructive eyes and complications, e. Endoscopic cyclophotocoagulation is an invasive procedure but allows visualization of the target tissues.

UBM is useful in the observation of postoperative changes and identification of postoperative complications. Normal filtering bleb black arrowhead , unobstructed filtration channel black arrow connected with the inner filtering opening white arrowhead. Obstruction of inner filtering opening white arrowhead which is usually led by the blood clot. The inner opening is presented but no intrascleral pathway black arrow and no fluid spaces in the bleb asterisk.

Scarring is presented at the bottom of the bleb black arrow that obstructs the effective outflow to conjunctiva. An intact thin trabeculo-descemetic membrane white arrowhead , an intrascleral lake and pathway under the scleral flap to subconjunctiva cavity white arrow in nonpenetrating trabecular surgery.

Exudation in the intrascleral cavity white arrowhead is usually formed by blood clot, which will decrease the aqueous outflow. Viscoelastic material in the intrascleral cavity white arrow which is used to prevent scleral flap adherence and maintain the filtration cavity. A The thick trabeculo-Descemetic membrane white arrowhead obstructed the outflow and compromise the IOP control.

B After the membrane was broken by laser goniopuncture, the aqueous can be drained through the gap white arrowhead , and the IOP was controlled in normal range. A year-old man presented with visual acuity finger counting, IOP 45 mm Hg.

Primary diagnosis was secondary glaucoma due to emulsified silicone oil in the anterior chamber. One week after the transcleral cyclophotocoagulation, IOP was 30 mm Hg. UBM reveals the atrophy of ciliary body asterisk in Fig. This suggested strong inflammation response of the treatment.

Trabeculectomy is one of the most widely performed glaucoma surgery procedures for glaucoma. UBM allows visualizing the status of surgical openings, outflow channel and filtering bleb. Thus, it is useful for identifying the causes of operation failure. Recently, there has been renewed interest in nonpenetrating trabecular surgery because of the advantage to avoid potential complications related to ocular entry, such as early hypotony and cataract progression.

Non-penetrating trabecular surgery is not as successful as trabeculectomy in reducing IOP. UBM is useful as being able to visualize the floor of sclerectomy, the intrascleral cavity and subconjunctival filtration not visible during slit lamp examination and thus able to assess the factors leading to surgical failure. A year-old man was diagnosed as neovascular glaucoma.

Phaco and IOL were performed previously on this eye. Two days after shunt implant surgery, hyphema occurred and obscured the visibility of drainage device. UBM revealed a cross-sectional black arrow in Fig. Complication of Intraocular Lens Implantation Fig. Intraocular lens dislocation: A the IOL dislocated to underneath the iris white arrow with the loop exposed in pupil area, B the IOL dislocation in sagittal axial, presenting as IOL lying at different distance to iris on two polars.

Case summary: A year-old male presented as blurring in the left eye which has had phaco combined with IOL implantation surgery 4 years ago. Fibrous exudation was also presenting in the corresponding angle asterisk. Cross-sectional image of posterior chamber. Intraocular lens includes body white arrow and loop white arrowhead. Cross-sectional image of anterior chamber. Relatively high osmotic materials, such as residual viscoelastics can absorb aqueous through the lens capsule and make the capsular bag distended to an abnormal degree.

The anterior displacement of the optic and iris diaphragm shallows the anterior chamber and may result in pupil block glaucoma.

Patients with this syndrome may often have an unexpected myopic overrefraction and increasing the risk of posterior capsular opacity. Residual lens cortex after IOL implantation, presenting as distinctly outlined mass with irregular reflectivity located at equator position of lens white arrow.

Slit lamp examination found that the diameter of CCC opening was approximately 4 mm, which was completely occluded by IOL optic. Case summary: A year-old female presented as having pain, redness, photophobia and blurring for 3 days. Primary diagnosis was anterior uveitis. Slit lamp examination found conjunctival injection, corneal edema, keratic precipitates, anterior chamber flares UBM demonstrated high reflectivity floaters in the anterior chamber Fig.

Intermediate uveitis is an insidious type of uveitis characterized by inflammatory cells in the anterior vitreous, inferior pars plana. Because it can be seen by routine examination, the patients are often presented as secondary cataract, iris synechiae, vitreous floaters and cystoid macular edema. UBM is able to detect these changes and therefore able to provide further evidence for the diagnosis. Case summary: A year-old female presented as having recurrent redness and blurring. Visual acuity was hand motion and IOP was 35 mm Hg.

Slit lamp examination demonstrated shallowing of anterior chamber, pupil membrane, iris convex and significant lens opacity. UBM imaging Fig.

Figure 48B demonstrated synechiae of anterior drainage angle white arrow and iris posterior synechiae white arrowhead. Figure 48C provided that inferior ciliary body was edema and covered by exudative material and membrane white arrow and inflammatory exudation in suprachoroidal lumen white arrow-head.

In Figure 48D , inflammatory exudation is also found covering the pars plana white arrow and peripheral retina white arrowhead.

Case summary: A 9-year-old boy presented with photophobia and blurring. Slit lamp revealed bilateral nystagmus, iris was absent from 2 to 4 clock hours, residual underdeveloped iris was presented from 10 to 2 clock hours. UBM revealed similar result. Aniridia: A revealed maldeveloped iris white arrow together with malformation of ciliary body, B revealed absolutely iris missing with zonules exposed white arrow. Silicone oil: A the highly reflective line white arrow is the interface of silicon oil, B Silicone oil emulsified in anterior chamber.

The interface is high reflection white arrow with echoic shadow underneath it white arrowhead. Normal pars plana, ora serrata and peripheral retina appear consecutive and smooth in UBM image. The highly reflective line is the anterior border of vitreous white arrow. UBM can detect retinal detachment located in the anterior part of vitreous cavity. In Figure 51A , the line represents the free end of detached retina in pars plana dialysis white arrow.

The fine line white arrow in Fig. Anterior proliferative vitreoretinopathy aPVR is one of the common causes leading postoperative retinal redetachment. Construction of vitreous incarcerated at the pars plana punctures during the operation is thought to be the causation of the complication.

Compared with three-mirror examination after pupil dilation, UBM supplies a convenient way to detect inner opening of punctures. Anterior PVR. UBM images revealed fibrous strips incarcerated at the operation puncture white arrow. Corneoconjunctival dermoid: It is a congenital abnormality, neoplasm is mainly composed of fibrous and lipid tissue covered by epithelium.

This neoplasm often affect conjunctiva or superficial layer of the cornea. Case summary: A 9-year-old girl was diagnosed as limbal dermoid. Slit lamp found a round-shaped yellow nodule on the temporal limbus. UBM image Fig. A clear boundary between the neoplasm and sclera is presented white arrow implying the tumor growing is self-limited without extension.

Image Fig. Case summary: A year-old man was diagnosed as corneal dermoid. Pathological testing confirmed the diagnosis of melanoma. UBM is helpful to identify the extent of neoplasm and therefore help decide the surgical treatment plan. Iris implantation cyst. UBM revealed a large cyst on the superior quadrants with iris atrophy and localized iris-cornea contact white arrowhead.

The cyst had thin septum white arrow and scatter reflectivity inside. UBM is helpful to identify the extent of cyst as well as the relationship with neighboring tissues.

Ciliary body neurilemmoma. Neurilemmoma is one of the benign tumor of ciliary body. The UBM image shows a huge ciliary body mass with regular internal content white arrow which turns the iris closing to the cornea with angle entrance obviously narrowed white arrowhead.

Choroidal melanoma. UBM examination shows the radial sectional image of a choroidal melanoma. A round shaped mass is noted extending centrally from posterior ocular wall asterisk. Secondary exudative retinal detachment occurred at the peripheral fundus white arrow.

Case summary: A year-old lady presented as having recurrent eye pain for 1 month. UBM revealed multiple iris cysts on the back of the iris in all quadrants, which push the iris root upward causing secondary angle closure black arrow. Cornea foreign body. A Fine iron wire white arrow and B tiny iron granula black arrow.

Anterior chamber angle foreign body. A piece of sharp metal debris was noted incarcerated in the chamber angle white arrow. The shadow of the foreign body blurred the echo of iris beneath it. Lens foreign body. The ciliary body process is markedly swollen white arrow , and there is no iris bombe. The scleral spur red arrow , cornea yellow arrow , iris orange arrow , and lens capsule green arrow are also visible. The treatment is supportive because the swelling will resolve following discontinuation of the medication.

Clinicians may prescribe topical aqueous suppressants to lower IOP while the episode abates but should avoid medications that contain sulfonamide. Peripheral iridotomy is not indicated, because the mechanism is not related to pupillary block.

This information can assist with the differentiation of the various etiologies of narrow or closed angles. He stated that he holds no financial interest in the products or companies mentioned herein. Katz may be reached at Jonathan S.

Myers may be reached at Douglas J. Rhee may be reached at ; dougrhee aol. George L. Spaeth may be reached at Ultrasonography of the Eye and Orbit. A high prevalence of occludable angles in a Vietnamese population. Incidence of acute angle-closure glaucoma after pharmacologic mydriasis.

Am J Ophthalmol. For Further Reading 1. Subsurface ultrasound microscopic imaging of the intact eye. Acute angle closure glaucoma. The Clinics Atlas of Office Procedures. Bilateral ciliary body swelling from Topomax. Arch Ophthalmol. Ultrasound biomicroscopy of the anterior segment. Mediguide to Ophthalmology. Vol 7. Ultrasound biomicroscopy in glaucoma.

In: Rhee DJ. Wilson, MD. Current Issue Archive. Rhee, MD ; George L. Spaeth, MD ; L. Myers, MD. Stuart Foster, PhD—utilizes a high-frequency transducer to deliver high-resolution images of the anterior segment. Typical B-mode ultrasonography performs at just 8 to 15 MHz with an approximate resolution of 0. Wilson, MD Richard P.