Indian Journal of Radiology Indian Journal of Radiology  

   Login   | Users online: 561

Home Bookmark this page Print this page Email this page Small font sizeDefault font size Increase font size     

 

HEAD & NECK NEURORADIOLOGY Table of Contents   
Year : 2001  |  Volume : 11  |  Issue : 2  |  Page : 75-79
Role of ultrasonography in ocular trauma


Department of Ophthalmology, Pt. B.D. Sharma PGIMS, Rohtak, India

Click here for correspondence address and email
 

Keywords: Ocular trauma, Ophthalmic Ultrasonography

How to cite this article:
Chugh J P, Susheel, Verma M. Role of ultrasonography in ocular trauma. Indian J Radiol Imaging 2001;11:75-9

How to cite this URL:
Chugh J P, Susheel, Verma M. Role of ultrasonography in ocular trauma. Indian J Radiol Imaging [serial online] 2001 [cited 2019 Jun 19];11:75-9. Available from: http://www.ijri.org/text.asp?2001/11/2/75/28378
Ultrasound has revolutionized the management of the traumatized eye. It provides the ophthalmologist with an instantaneous look into an eye with opaque ocular media. Detection of abnormalities that cannot be visualized clinically when the cornea, lens or vitreous is opaque has been a limitation of diagnosis in ophthalmology in past. Such circumstances occur frequently in ocular trauma when corneal edema, hyphema, secondary cataract, or vitreous hemorrhage or debris obscure the observer's view and makes thorough clinical examinations impossible. Ultrasonography (US) has emerged in recent years as a useful technique for detecting and outlining soft tissue abnormalities of the eye and orbit regardless of intervening opacities or tissues. It is a sensitive and accurate technique, which has some additional advantages over conventional radiographic techniques.


   Role in Ocular Trauma Top


Ocular US is generally used as a B-scan imaging technique while A-scan has a corroborative and correlative role. Sterility is essential if the globe is open or a wound has been recently closed. Probes should be sterile or they may be placed in sterile rubber sleeves. In case of a ruptured globe, it is highly recommended that primary closure should be performed before US examination. If US examination is performed prior to primary closure, it should be performed with the least possible trauma. The small A-scan probe may be gently placed on the conjunctiva in an area away from the wound, or the probe may be placed on closed lids with copious sterile methylcellulose applied for optimal sound penetration. Whenever examining through closed lids, very high tissue sensitivities must be used.


   Examination of Specific Ocular Structures after Trauma: Anterior Chamber Top


Some injuries such as hyphema and corneal opacities will obscure the direct visualization of the anterior segment and will require ultrasound assessment. In these instances, ultrasound may reveal the presence of shallow anterior chamber, gross angle recession and ciliary body detachment. In the presence of hyphema, ultrasonography may reveal echoes in the anterior chamber [Figure - 1]. Angle recession is suspected when there is a deep anterior chamber and a wide angle. Anterior chamber depth can be obtained by A-scan ultrasonic biometry. On B-scan, in case of a flat anterior chamber, echoes from the posterior cornea and anterior surface of iris merge with each other. Demonstration of anterior segment structures or foreign bodies in anterior chamber is achieved by immersion technique or water balloon technique [Figure - 1]. New ultrasound biomicroscopy is best for anterior segment evaluation [1].


   Lens Top


Ocular trauma can also affect the lens. The presence, integrity and location of the lens should be assessed. The normal lens produces extremely low internal reflectivity, whereas a dense cataract often produces highly reflective echoes. Subluxation and dislocations of the lens also may be easily detected with US [Figure - 2]. The anterior and posterior lens capsule may be ruptured with severe blunt trauma [Figure - 3]. US detection of lens rupture may be useful in determining the best surgical approach for cataract extraction. Vitreo-retinal abnormalities are generally associated with traumatic cataract. A study has reported a 20-30% incidence of vitreo-retinal abnormalities in eyes with a traumatic cataract. This emphasizes the need for US evaluation [2].


   Vitreous Top


Vitreous hemorrhage is a common finding in patients with trauma. US is useful in detecting the density and location of hemorrhage. In fresh, mild hemorrhage, dots and short lines are displayed on B-scan and a chain of low amplitude spikes is found on A-scan. The more dense the hemorrhage, more opacities are seen on B-scan and higher is their reflectivity on A-scan. If the hemorrhage spreads diffusely, it creates scattered low amplitude echoes. Organization of blood creates interfaces that may have a pseudomembranous appearance on B-scan and variable reflectivity on A-scan. Variable degrees of posterior vitreous detachment (PVD) usually accompany vitreous hemorrhage [Figure - 4]. On B-scan, detached vitreous is usually smooth and may be thick posteriorly when blood is layered along its surfaces. Reflectivity in cases of PVD varies from extremely low as in the normal eye to extremely high as in the case of dense hemorrhage. Kinetic US typically shows an undulating after-movement on B-scan, which normally allows the PVD to be distinguished from less mobile retinal and choroidal detachments. On A-scan, PVD typically exhibits marked horizontal and vertical spike after movement. However, there are situations in which the acoustic behavior of PVD is similar to retinal detachment, so the distinction of PVD from retinal detachment may be quite challenging. A hemorrhagic track can also occur along the path of a sharp object or foreign body [Figure - 5]. USG is helpful in tracing the full course of the track, which is important for revealing lesions at the distal end, such as posterior perforation, retinal or choroidal detachment or foreign body. This information is essential in planning surgical management. Vitreous traction bands that can be demonstrated ultrasonically are an indirect sign of vitreous incarceration within a perforation site. The bands may lead to rupture site on one side and the opposite site should be examined for retinal detachment [Figure - 6].


   Retina and Choroid Top


One of the most important roles of US is to evaluate the status of the retina in opaque media. Rhegmatogenous and tractional retinal detachment (RD) generally found in ocular trauma can be diagnosed by ultrasound. Traction can occur within the vitreous base near the injury site or at the opposite side. RD typically appears on US as a bright, continuous, smooth and somewhat folded membrane within the vitreous, which is reflective and freely moving on real time imaging. The movements become less pronounced in long standing detachments. When total or extensive, the detached retina has a typical triangular shape with insertion into the optic disc and ora serrata [Figure - 7]. On A-scan, a 100% tall spike is produced when the sound beam is directed perpendicular to the detachment. A hemorrhagic RD produces echoes in the subretinal space on B and A-scans. The traction pattern appears as a tented or tabletop configuration with the vitreous band connected to the anterior surface [Figure - 8].

In case of blunt trauma, a peripheral retinal tear and peripheral retinal dialysis may occur. This can be detected by noting the disinsertion of the peripheral retina from the ora serrata on longitudinal B-scans. Dialysis is most commonly seen in the upper nasal quadrant [Figure - 9]. The A-scan may also be useful in evaluating the peripheral retina.

Choroidal detachment occurs frequently in ocular trauma. On B-scan choroidal detachment typically appears as a smooth, thick, dome-shaped membrane in the periphery with little after-movement on kinetic evaluation [Figure - 7]. On A-scan (at tissue sensitivity) a thick, steeply rising 100% high spike is produced. On careful inspection, on low sensitivity, the spike is observed to be double peaked. Slight vertical after-movement is normally appreciable during kinetic evaluation on A-scan. When choroidal detachments are present at 360 degrees and are displayed with a transverse B-scan approach, multiple bullae produce a scalloped appearance named "kissing choroidal detachment" [Figure - 10].

In the case of massive suprachoroidal hemorrhage where the detachments are highly elevated, US follow-up is of utmost importance in evaluating clot size and appearance. This information will help to determine the time for surgical intervention.


   Sclera Top


Blunt trauma can lead to posterior scleral rupture that may be difficult to detect clinically and with USG, although the area may show irregular contours and decreased reflectivity. However, such a rupture should be suspected when some indirect signs exist:

  1. Incarceration of vitreous and vitreous hemorrhage with PVD
  2. Demonstration of folds and traction bands that extend in the direction of rupture
  3. Thickening or detachment of retina or choroid
  4. Hemorrhage in episcleral space closest to the site [Figure - 6].


Ocular trauma can lead to scleral folds, which are diagnosed by ultrasound and appear as irregularities in globe contour, which may mimic small dome-shaped elevations, highly reflective at their top and shadowing the orbital tissues. Because of the shadow, they mimic a foreign body and may also resemble choroidal detachment. This is one reason for US evaluation prior to primary closure. Foreign Bodies US is a complementary modality to radiology in the detection and localization of foreign bodies. It can give additional information regarding the exact location within the eye and the extent of damage to surrounding tissues. B-scan offers advantages in determining the foreign body's position and distance from ocular structures. A-scan ultrasonography displays the relative echo amplitude of foreign body and other tissues. The major value of US in detecting foreign bodies is its independence from radio-opacity. Another advantage of this diagnostic modality is the ability to differentiate between intraocular and extraocular foreign bodies when they are located near the sclera. In addition, the mobility, magnetic properties and shift in position of the foreign body between the time of initial study and the time of surgery can be accurately evaluated. However, this modality does have some limitations. Softer materials, which are only intermediately reflective (wood and vegetative materials) are more difficult to detect. Small particles particularly located at the orbital apex and those lodged in highly reflective tissues can be missed. Metal or glass foreign bodies deflect or absorb sound so that they produce an anechoic area posterior to the body [Figure - 11]. Shotgun pellets or other similar foreign bodies produce a "ringing artifact" which is a series of echoes trailing behind the foreign body just like a comet tail. If the foreign body is not visible clearly due to echoes from nearby tissues then gain should be reduced so that echoes from less reflective tissues are obliterated and the foreign body stands out clearly. Plain radiographs and CT are superior for detecting foreign bodies, especially if they are multiple, although US contributes to their exact localization with respect to other ocular structures. US is also helpful in detecting orbital hemorrhage, abscess and granulomas secondary to penetrating injury of the orbit and mucoceles and pyoceles resulting from fractures of the sinuses. US has only a limited role in fresh cases of trauma, but plays a major role in therapeutic decisions related to the late effects of ocular trauma. It is noninvasive, well-tolerated and a safe procedure. US examination, however requires technical skill, experience and sound judgment to be a reliable test.

 
   References Top

1.Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. Clinical use of ultrasound biomicroscopy. Ophthalmology 1991; 98: 287-295.   Back to cited text no. 1  [PUBMED]  
2.Kaskalogu M. US findings in eyes with traumatic cataracts. Am J Ophthalmol 1985; 9: 496.  Back to cited text no. 2    

Top
Correspondence Address:
J P Chugh
115-L, Model Town, Rohtak 124 001
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


Rights and PermissionsRights and Permissions


    Figures

[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10], [Figure - 11]

This article has been cited by
1 Ocular trauma- Spectrum of ultrasound findings: A prospective study
Agarwal, N. and Gupta, V. and Gupta, V. and Verma, A.
Indian Journal of Public Health Research and Development. 2013; 4(1): 138-142
[Pubmed]
2 Scleral rupture in dogs, cats, and horses
Rampazzo, A., Eule, C., Speier, S., Grest, P., Spiess, B.
Veterinary Ophthalmology. 2006; 9(3): 149-155
[Pubmed]
3 Sonographic evaluation of ocular trauma in Ilorin, Nigeria
Nzeh, D.A., Owoeye, J.F.A., Ademola-Popoola, D.S., Uyanne, I.
European Journal of Ophthalmology. 2006; 16(3): 453-457
[Pubmed]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  


    Role in Ocular T...
    Examination of S...
    Lens
    Vitreous
    Retina and Choroid
    Sclera
    References
    Article Figures

 Article Access Statistics
    Viewed7598    
    Printed228    
    Emailed15    
    PDF Downloaded0    
    Comments [Add]    
    Cited by others 3    

Recommend this journal