Ординатура / Офтальмология / Учебные материалы / Clinical Diagnosis and Management of ocular trauma

188

Clinical Diagnosis and Management of Ocular Trauma

hemorrhage such as leukemia, accidental trauma,

4.

Moreira CA Jr, Ribeiro MD, Belfort R Jr. Epidemiological

leukemia, thrombocytopenia, anemia, etc. should be

study of eye injuries in Brazilian children. Arch

ruled out. Severe visual morbidity with shaken baby

Ophthalmol 1988;106:781-84.

5.

Rapoport I, Romem M, Kinek M, et al. Eye injuries in

syndrome may be due to retinal detachment, optic

children in Israel. A National Collaborative Study. Arch

nerve atrophy or cortical blindness.

Ophthalmol 1990;108:376-79.

6.

Canavan VM, O’Flaherty MJ, Archer DB, et al. A ten year

Eye Injury Prevention

survey of eye injuries in Northern Ireland. Br J

Ophthalmol 1980;64:618-25.

7.

Holden R, Morsman DG, Davidek GMB, O’Conner GM.

The vast majority of eye injuries are preventable. Key

External ocular trauma in instrumental and normal

components of prevention include parental

deliveries. Br J Obstet Gynecol 1992;99:132.

supervision, education of children and protective

8.

Angell LK, Robb RM, Berson FG. Visual prognosis in

eyewear. Ophthalmologists and parents must reinforce

patients with ruptures in Descmet’s membrane due to

forceps injury. Arch Ophthalmol 1981;99:21-37.

the importance of not playing with objects like

9.

Sezen F. Retinal hemorrhages in new born infants. Br J

gillidanda, fire-crackers and bow and arrow. Health

Ophthal 1970;55:248.

education on the preventive aspects of ocular trauma

10.

Volpe NJ, Larrison WI, Hersh PS et al Secondary

in schools as well as through mass media like television

hemorrhage in traumatic hyphema. Am J Ophthalmol

can help in achieving this goal.

1991; 112: 507-13.

Protective eyewear is the most important measure

11. Thomas MA, Parrish RK, Feuer WJ. Rebleeding after

to prevent eye injuries in children. Plano polycarbonate

traumatic hyphema. Arch Ophthalmol 1986 Feb;

104(2):206-10.

goggles with a 2-3

mm center thickness are

12.

McGetrick JJ, Jampol LM, Goldberg MF, et al.

recommended for sports.

Aminocaproic acid decreases secondary hemorrhage

after traumatic hyphema. Arch Ophthalmol 1983 Jul;

Summary

101(7):1031-33.

13.

Kutner B,Fourman S, Brein K Aminocaproic acid

reduces the risk of secondary hemorrhage in patients

Ocular trauma is an important cause of monocular

with traumatic hyphema. Arch Ophthalmol 1987 Feb;

blindness in children. Due to young age, inability to

14.

105(2):206-08.

cooperate with examination and the potential for

Stern WH, Monclal KM. Vitrectomy instrumentation for

surgical evacuation of total anterior chamber hyphema

development of amblyopia, children presenting with

and control of recurrent anterior chamber hemorrhage.

eye injuries are evaluated and treated slightly differently

Ophthalmol Surg 1979; 10: 34-37.

from adults. Proper communication should be

15.

McCuen BW, Fung WE. The role of vitrectomy

maintained between the ophthalmologist and family

instrumentation in the treatment of severe traumatic

throughout the course of treatment.

16.

hyphema. Am J Ophthalmol 1979;88:930-34.

Dass AB, Ferrone PJ, Chu RY etal. Senstivity of spiral

computed tomography scanning for detecting intraocular

References

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membrane removal for traumatic macular holes.

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18.

Amari F, Ogino N, Matsumura M et al. Vitreous surgery

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Chow DR, Williams GA, Trese MT et al. Successful closure

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Margherio AR, Margherio RR, Hartzer M et al Plasmin

3. Niiranen M, Raivio I. Eye injuries in children. Br J

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holes. Ophthalmology 1998 Sep;105(9):1617-20.

190

Clinical Diagnosis and Management of Ocular Trauma

First there is direct contusion tissue damage at the

globe status is obvious, careful documentation of these

site of impact. This is known as a coup injury, and

circumstances, as well as the use and type of safety

includes retinal edema, necrotic changes, and

glasses or other protective devices, has medical and

choroidal hemorrhage at the site of impact.

legal relevance. The history should determine the

Second, injury can occur distant from the impact

preinjury ocular status and the possibility of extraocular

site as the force is transferred through the globe

trauma; the ocular baseline should include preinjury

to a contralateral site. This is called the contracoup

vision, refractive status (myopic eyes are affected with

injury; examples of it include retinal edema and

more severity with minor traumas), preexisting ocular

choroidal contusions in the posterior pole; in these

diseases (e.g. retinal diseases, pseudoexfoliation,

lesions the posterior pole was not impacted directly,

glaucoma), and previous ocular surgery (e.g. cataract,

but the transmission of forces affect it in different

retinal surgery). The note of circumstances that should

degree.

raise suspicions of open globe injuries is mandatory,

Finally, there are injuries caused by the globe

high-speed projectile injuries, use of power tools, high-

deformation; some authors have documented by

speed grinding of metal, leak from high-pressure

high-speed cinematography, globe deformation

hydraulic system, metal-on-metal impact, sharp

following the application of blunt forces to the

penetrating injuries and severe blunt injury (racquetball

cornea. In these movies we can see initially how

or golf ball, stick or bat injury to orbit).

the anteroposterior axis is compressed; then the

anteroposterior axis is decompresses and so a

Individual Pathologies Description

rebound expansion occurs. Then the equatorial

axis begins to expand as the anteroposterior axis

COMMOTIO RETINAE

compresses but doesn’t reach maximum expansion

until after the anteroposterior axis begin its rebound

Definition and Clinical Findings

decompression. This tremendous change of intra-

Commotio retinae is also known as Berlin’s edema, but

ocular forces of compression and decompression

the latter term is not completely appropriate. The clinical

within different axis of the globe, creates shearing

characteristic of this condition is a confluent area of

forces within the eye at tissue interfaces that are

retinal whitening due to outer photoreceptor disruption

especially concentrated at the vitreous base.

and RPE damage, but not edema. Blood vessels are seen

Choroidal rupture, vitreous base avulsion, iris root

distinctly and are undisturbed under the retinal

disinsertion, retinal dialysis and tears, and posterior

whitening. Commotio retinae results in retinal

vitreous separation are examples of injuries caused

opacification following blunt trauma. Mild commotio

by these shearing forces.

retinae usually settles spontaneously with minimal

After reading this, the clinical comprehends that

sequelaebutmoreseverecasesareassociatedwithvisual

he must be aware of damage caused by ocular blunt

loss. Commotio retinae can occur anywhere in the

trauma at any site of the eye; so a complete evaluation

retina, but it is usually maximal in the area opposite to

of all structures is mandatory, even in case of an

the blow (countracoup injury). So, explaining the

“pretended minor trauma”.

pathophysiology of the condition, the retinal changes

Initial Evaluation

are caused by a contrecoup that is created by blunt

trauma, with the force being transmitted through the

vitreous and finally onto the retina and choroid

Proper identification and management of patients with

(Figs 31.1 and 31.2).

posterior segment injury begin with a systematic

approach to obtaining a complete history and conduc-

Histopathology

ting a thorough ophthalmic examination. The reader

will be able to see more details in some other chapters

Immediately after injury, the only abnormality is

of this book, but some important points will be

disruption of the receptor outer segments. From one

featured regarding the posterior segment blunt trauma;

to six days after trauma, many receptor cells undergo

because open and closed globe injuries are approached

degeneration. The retinal pigment epithelium phago-

differently it is important for the ophthalmologist to

cytoses the degenerating outer segments, occasionally

make this determination as soon as possible.

migrating into the retina. There is no extracellular retinal

The circumstances surrounding the trauma are

edema. The opacity of commotio retinae seems to

important and should be obtained directly from the

represent disrupted receptor cells. Visual loss may result

patient and/or an eyewitness in particular if the patient

from permanent loss of receptors. The pigment

is unable to communicate. Even in cases in which the

epithelial response to traumatic receptor damage is

192

Clinical Diagnosis and Management of Ocular Trauma

Green suggested that fluid movements of the liquefied

macular holes. This sudden traction exerted on the

vitreous in an enlarged premacular bursa can exert

anatomically thin fovea results in an immediate

traction on the remaining formed cortical vitreous, with

formation of a macular hole in most cases (Fig. 31.3).

that traction transmitted tangentially to the fovea.

These finding suggests that the named mechanisms

Treatment

are important in the generation of tangential traction

Vitrectomy surgery for idiopathic macular holes has

leading to the macular hole formation, and cellular

been shown to improve vision in some eyes. Current

proliferation may not play a major role in their

techniques include removal of the posterior hyaloids

pathogenesis. Studies also found that retinal fragments

and all epiretinal membranes from the macular area

are a rare feature of the vitreous in these patients; they

and prolonged postoperative macular gas tamponade.

are thus unlikely to be a constituent of macular hole

However, the role of vitrectomy surgery for a macular

opercula. Opercula are therefore better termed

hole caused by blunt ocular trauma is not still well

pseudo-opercula, as has been previously suggested.

established.

A mild chronic inflammatory infiltrate (lymphocytes)

The results of different series are encouraging.

is present in some cases of macular holes. Inflammation

Despite significant blunt trauma of different types,

and cellular or fibrocellular membrane fragments are

vitrectomy surgery for macular holes can result in a

more frequent in traumatic holes than in idiopathic

high likelihood of improved vision and a risk of comp-

holes. The significance of this difference is unclear, but

lications, that seems no greater than with vitrectomy

it is likely a direct result of the initial trauma.

surgery for idiopathic macular holes. Further, studies

Studies of Mechanical Forces

of different approaches with posterior vitrectomy are

needed to establish a consistent result for this condition;

Evidence from animal studies and biomicroscopic and

meanwhile different approaches are being performing

surgical observations of patients with a traumatic

according the case, the criteria and the resources

macular hole strongly suggest that vitreous traction is

worldwide.

important in their pathogenesis. Experimental

observation shows that sudden compression of the

TRAUMATIC RETINAL TEARS

globe produces an immediate stress on the retina at

(RETINAL BREAKS)

points of vitreous attachment. High-speed photography

Despite the surgical management (enough material to

of blunt trauma reveals indentation of the cornea

fill an entire book), we will describe in this stage some

followed by expansion of the globe at the equator.

features that can differentiate a Traumatic retinal Tear

This outward expansion of the equator is followed by

from those Non-Traumatic and the clinical features to

flattening of the posterior pole and then posterior

evaluate during the initial examination.

displacement of the posterior pole of the eye. It seems

Peripheral retinal breaks occur at sites of strong

likely that with this trampoline-like movement of the

vitreoretinal adhesions. During blunt trauma vitreo-

posterior pole, traction forces may in fact be along

retinal traction may occur by the forceful displacement

the surface of the retina, that is tangential, not unlike

or separation of the vitreous. Globe deformation also

what occurs in a more gradual manner with idiopathic

causes various shearing forces that further amplify the

vitreoretinal traction (coup and countercoup).

Retinal breaks resulting from trauma can be

horseshoe-shaped flap tears or operculated holes.

Formed vitreous is often attached to the elevated flap

of a horseshoe tear and the free-floating operculum

of the hole. These tears can occur along the vitreous

base or at the edge of lattice degeneration or

chorioretinal adhesions. If a retinal vessel is involved

in the tear, a dense vitreous hemorrhage can occur;

the attending surgeon must always remember that a

vitreous hemorrhage can advice about a retinal rupture,

that sometimes is covered by the blood at the initial

examination.

Giant retinal tears are retinal breaks that extend

3 or more clock hours. They occur at the edge of the

Fig. 31.3: Traumatic macular hole

vitreous base, which remains attached to the anterior

Management of Blunt Retinal Trauma

193

flap; their formation will depend upon the transmission

true in traumatic detachments associated with

of forces inside the globe, but also upon some previous

subretinal or vitreous hemorrhage, giant retinal tears,

retinal damage (e.g. high myopia).

or severe ocular contusions in which there has been

A retinal dialysis is a discontinuity or separation

an opportunity for RPE and other fibroglial cells to

of the retina from the pars plana at the ora. It is most

gain access to the vitreous cavity. Even a condition

frequently traumatic in nature and is characterized

like vitreitis can lead to retinal detachment because

by attachment of the vitreous to the posterior retinal

of its inflammatory condition.

flap. This is in contradistinction to retinal tears, in

Some studies conducted to study phakic retinal

which the vitreous usually adheres to the anterior

detachments have characterized some of the implied

flap; anyhow, vitreo-retinal traction is present in almost

features and have helped to establish improved

all the times. Traumatic retinal dialysis occurs most

guidelines for medicolegal determinations. Myopes

often in either the inferotemporal or superotemporal

typically developed giant tears and nasal dialyses;

quadrant. The risk of progression to retinal

emmetropes frequently developed inferotemporal

detachment is significant.

dialyses. It also has been noticed that lattice degene-

Therefore, all traumatic retinal tears and dialyses

ration did not increase post-traumatic detachments risk.

are treated prophylactically with photocoagulation or

Dialyses and giant tears caused 69% of traumatic

cryotherapy. Giant retinal tears that continue to tear

detachments in comparison with 6% of the cause of

despite photocoagulation also can be treated with

nontraumatic detachments. Experience has shown that

scleral buckling.

the overwhelming majority of traumatic retinal

detachments are rhegmatogenous in origin. Retinal

TRAUMATIC RETINAL DETACHMENT

breaks are predominantly located within the vitreous

base region but may occur at sites of focal scleral impact

Like in the previous section, the retinal detachment

or from posterior vitreous avulsion.

can include entire books; we will describe only some

features regarding the traumatic etiology of this

Management

condition.

Although the use of scleral buckling techniques alone

Mechanism of Pathology

may be sufficient, closed microsurgery may be required

in some cases to relieve retinal traction and to facilitate

Traumatic retinal detachments occur primarily as the

the identification and permanent closure of the retinal

result of retinal changes at the vitreous base. Goffstein

breaks. Prophylactic measures including the use of

and Burton, reported that 53% of traumatic retinal

closed microsurgery, play a vital role in the manage-

detachments were caused by retinal dialyses, 16% by

ment of traumatic retinal breaks and prevention of

giant retinal tears, 11% by horseshoe flap tears, and

complex retinal detachment.

8% by tears at the edge of lattice. Retinal detachments

Traumatic retinal detachments are treated primarily

can also happen secondary to traumatic tears of the

by scleral buckling. The results and visual outcomes

ciliary epithelium. Sometimes during the clinical evalua-

are quite favorable. As previously mentioned, most

tion is difficult to identify the specific cause.

of these patients (young patients) have well-formed

vitreous with posterior hyaloid attachment. Sometimes

The majority of these traumatic tears and detach-

during a pars plana vitrectomy a posterior vitreous

ments occur in younger individuals. The vitreous often

detachment may be difficult to create and the

is quite well formed and has not yet undergone a

morbidity associated with the vitrectomy may be

posterior vitreous detachment (PVD). This well-formed

greater than that seen with scleral buckling.

vitreous often limits the progression of retinal detach-

Because of these reasons, some authors attempt

ment, especially if it is caused by an inferior dialysis.

to avoid an intraocular approach in the repair of these

As time progresses and the vitreous becomes more

detachments. However, there are several well known

liquid or separates further, the detachment can then

indications for a primary repair of retinal detachment

progress more rapidly. This explains why many

by pars plana vitrectomy; vitreous hemorrhage

traumatic detachments do not present until several

obscuring visualization, posteriorly dislocated crystalline

months or even years after the original trauma. At this

lens, giant retinal tear with everted flap, proliferative

point the physician must remember that after an initial

vitreoretinopathy, subretinal hemorrhage and a large

trauma, the patient must be educated to follow

irregular posterior retinal tear.

multiple evaluations, even without symptoms; this

In these traumatic cases it is useful sometimes to

condition can imply even some legal issues.

combine the vitrectomy with an encircling element to

Detachments also can be associated with

support the vitreous base on a broad, shallow buckle.

proliferative vitreoretinopathy (PVR). This is especially

The final decisions must be taken by the attending