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

The new ocular trauma terminology system.1,2,31,32 provides definitions for the commonly used eye trauma terms as follows:

1.Eyewall—For clinical and practical purposes, the term eyewall must be restricted to the rigid structures of the sclera and cornea.

2.Closed-globe injury—The eyewall does not have a full-thickness wound. Either there is no corneal or scleral wound at all (contusion) or is it only partial thickness (lamellar laceration).

3.Open-globe injury—The eyewall has a full-thickness wound. The cornea and/or sclera sustained a through-through injury; depending on the inciting object’s characteristics and the injury’s circumstances, ruptures and lacerations are distinguished; the choroid and the retina may be intact, prolapsed or damaged.

4.Rupture—Full-thickness wound of the eyewall, caused by a blunt object; the impact results in momentary increase of the intraocular pressure. The eyewall gives way at its weakest point (at the impact site or elsewhere; example: an old cataract wound dehisces even though the impact occurred elsewhere); the actual wound is produced by an inside-out mechanism.

5.Laceration—Full-thickness wound of the eyewall, usually caused by a sharp object; the wound occurs at the impact site by an outside-in mechanism.

6.Penetrating injury—Single laceration of the eyewall, usually caused by a sharp object. No exit wound has occurred; if more than one entrance wound

References

1.United States Eye Injury Registry. Eye trauma epidemiology and prevention. Available at: http:// www.useironline.org/prevention.htm. Accessed July 6, 2008.

2.World Eye Injury Registry. Available at: http:// www.weironline.org/prevention.htm. Accessed July 6, 2008.

3.Serrano JC, Chalela P, Arias JD: Epidemiology of Childhood Ocular Trauma in a Northeastern Colombian Region. Arch Ophthalmol 2003;121:1439-1445.

4.Pizzarello LD. Ocular trauma: time for action. Ophthalmic Epidemiol 1998;5:115-116.

5.Negrel AD, Thylefors B. The global impact of eye injuries. Ophthalmic Epidemiol 1998;5:143-169.

6.McGwin G, Xie A, Owsley C: The rate of eye injury in the United States. Arch Ophthalmol 2005;123:970-976.

7.Mieler W: Overview of ocular trauma. In Principles and Practice of Ophthalmology. 2nd edition. Edited by: Albert D, Jakobiec F. Philadelphia, WB Saunders Co. 2001;5179.

8.Tielsch JM, Parver L, Shankar B: Time trends in the incidence of hospitalized ocular trauma. Arch Ophthalmol 1989; 107:519-523.

9.McCarty CA, Fu CL, Taylor HR: Epidemiology of ocular trauma in Australia. Ophthalmology 1999; 106:18471852.

10.Desai P, MacEwen CJ, Baines P, Minassian DC: Incidence of cases of ocular trauma admitted to hospital and incidence of blinding outcome. Br J Ophthalmol 1996; 80:592-596.

11.Klopfer J, Tielsch JM, Vitale S, See LC, Canner JK: Ocular trauma in the United States: eye injuries resulting in

Introduction

Classification is the basis of understanding a subject. Duke-Elder has broadly divided ocular trauma (Injuries) into mechanical and non-mechanical.1 He has also divided them into several types depending on the environment such as industrial, agricultural, travel, etc.2 Several other authors have also classified ocular trauma is different ways.3,4 However, one problem with all these classification has been the variability of terminology which has been used by different authors in different ways like laceration, penetration, perforation, blunt, sharp, etc. In absence of standardization of terminology the literature has become confusing and non-comparable. In a landmark paper Kuhn et al standardized the terminology in ocular trauma and gave a standardized classification of ocular trauma which has been universally accepted.5 Other authors have further elaborated this and gave more details which are useful for prognosis.6,7

Kuhn et al have basically divided eye injuries into closed globe and open globe types, the tissue of reference being the cornea and sclera which they termed as eyewall.5 Closed globe injuries include contusion in which there is no wound of cornea or sclera. In lamellar laceration there is a partial thickness wound in cornea or scleara. In either case there is no full thickness wound. In open globe injury there is always a full thickness wound. This can occur from a blunt object with an inside out mechanism and is termed rupture. It can also occur by sharp objects by an outside in mechanism and is termed laceration. Laceration includes penetration (single laceration with one wound of entry), perforation (double laceration with one wound of entry and one wound of exit) and intra-ocular foreign bodies with single entrance laceration. Figure 2.1 explains this classification.

The above classification is ideal for mechanical injuries. However, ocular trauma includes many nonmechanical injuries like chemical, thermal, traditional, and others. These injuries can not be classified by the

Fig. 2.1: Classification of ocular trauma after Kuhn et al

above classification. For them better classification are available, e.g. Dua’s classification for ocular surface burns.8 Secondly the ocular adnexa including the lids, lacrimal apparatus, conjunctiva and orbit are parts of ocular trauma. The above classification has not taken account of this category.

Lastly it may be mentioned that any subject can be viewed from many angles and thus can have more than one classifications on the parameter chosen as the basis of classification and each of the classifications has its validity. Thus uveitis can be divided anatomically into anterior, intermediate, posterior, and pan uveitis. From pathological point of view it could be granulomatous or non-granulomatous; clinically it could be acute, chronic or recurrent and etiologically it could be infective, allergic, toxic or traumatic.9 Similarly keratoplasty can be lamellar or penetrating or mushroom from depth consideration. It can be partial, sub-total or total from diameter consideration. From objective point of view it could be optical, therapeutic, cosmetic or preparatory.10

Considering the above points it was thought to develop a more comprehensive type of classification of ocular trauma which is being presented in

Fig. 2.2.

Ocular trauma is first divided into local, associational and environmental. In local the injury is limited to eyeball and ocular adnexa; in associational it is associated with head injury (affecting visual pathway) or face as in blast injuries or with many organs of the body known as polytrauma. Here the life of the patient assumes primary importance. As the name suggests the environmental injuries depend on the environment and could be congenital, industrial, agricultural, travel (RTA*) criminal or casual (usually domestic). The local injuries are further divided into mechanical and nonmechanical types. The latter includes the chemical, thermal, radiational, electrical, ultrasonic and barometric. The mechanical injuries are divided into adnexal and global. The former include the lids, lacrimal apparatus, orbit and conjunctiva. Globe injuries are again divided into structural (anatomical) and pathological. The former include the anterior segment and posterior segment injuries with the details of structures included in each group. The pathological group represents the current classification suggested by Kuhn et al.5 Though open globe injury includes IOFB (intra-ocular foreign bodies) but the closed globe group does not include EOFB (extra-ocular foreign bodies) in Kuhn’s classification. The author has included them firstly because they are extremely common: they are extremely painful and lastly if they are in center they can cause extreme loss of vision.

In this group the author has also included IMFB (intra-mural foreign bodies). If the tissues of reference is cornea and sclera (eyewall) what is within it will be intra-ocular and what is outside it will be extra-ocular. But whatever is within the coats of eyewall is neither intra-ocular nor extra-ocular. The author has coined this word ‘EMFB’ quite some time back and it has been used at other places. This group also includes dislocations which may be anterior, posterior, and inferior (rarely they could be superior). In the pathological group in addition to closed and open globe there can also be destructive globe injuries which includes traumatic enucleation, evisceration and a full thickness laceration which covers one third of globe circumference or more. In these cases chances of functional recovery are absent.

The subject of ocular trauma is very wide and variable and perhaps no classification can adequately encompass all the entities included in ocular trauma. Nevertheless in our present state of knowledge it address some of points lacking in the existing classification and is fairly comprehensive. It may be stated that this classification is not totally exclusive and different combination of different categories are possible.

Acknowledgement: I wish to express may gratitude to the Ocular Trauma Society of India to encourage me in formulating this classification and accepting it after giving useful suggestions.

Introduction

A disease can be managed adequately only when it is properly evaluated. Evaluation can either be clinical, done by the clinician himself or investigational done by sophisticated machines usually by other specialists like pathologists, radiologists, etc. Clinical evaluation includes a careful history and a thorough clinical examination of the patient.

Before taking a detailed history two conditions have to be ruled out. If with ocular trauma there is a life threatening situation; respiratory, cardiovascular or neurological, the patient should be immediately referred to appropriate physician or surgeon after a quick preliminary examination.1 Secondly if there is an acute ocular emergency like chemical burn, severe bleeding or central retinal artery occlusion treatment has to be started before or during evaluation.

Injuries are very common in children.2-6 In clinical evaluation the approach to child has to be a little different from that in adults. Pain may cause severe blepharospasm, watering and in an unfamiliar situation the child is bound to be most unwilling to be examined or even questioned. The approach has to be very gentle and indirect. It is better not to touch the patient initially and let him remain comfortable in mother’s lap. After some time it may be possible to examine the eye with fine retractors along with assurance and coaxing. Should these tricks fail the child has to be examined under sedation or general anesthesia. In some cases it may be feasible to treat also once he is under anesthesia.

In older patients one should begin with a careful detailed history. History may be taken from the patient, a relative or a witness. In rural areas there is more risk of infection. The exact circumstances of the injury has to be ascertained first. This includes the location, object of injury along with its shape, size, and velocity. Its chemical nature and whether its is solid, fluid, or gaseous has also to noted. Exact time of injury and the various symptoms along with their severity should be recorded. It is important to know

pre-trauma vision in both eyes and the time when food/ drink was taken last. Medical and/or surgical treatment received should be noted in details and tetanus immunization should be ascertained. In past history diseases like diabetes mellitus, hypertension, bleeding disorders, HIV/AIDS, and allergy to drugs should be noted. It is important to know alcohol consumption and use of other drugs. All previous eye surgeries done should be recorded especially cataract, keratoplasty, and radial keratotomy.

After a careful history, examination of the eye is very important for clinical evaluaiton. This includes general, structural and functional examination. Structural examination would include adnexal, anterior segment and posterior segment examination.

General Examination

In all serious injuries pulse, respiration, temperature, and blood pressure should be recorded first to decide whether the case should be first seen by an ophthalmologist or to be referred to a physician or surgeon. The general behavior of the patient and level of conciousness should also be noted. Any evidence of injury in the neighboring area or organs should also be observed.

Structural Examination

OCULARADNEXA

Orbit

The position of globe in orbit should be noted. There may be exophthalmoso, enophthalmos, downwards dislocation (hypophthalmos) or upward dislocation (hyperophthalmos) which is rate. Orbital rim should be palpated for any local irregularity or tenderness indicating fracture. Emphysema in the surrounding area would be additional proof. Compressibility of globe into orbit should be noted. More resistance indicates orbital hemorrhage or hematoma besides tumor mass.

Lower lid injuries with sharp objects is commonly associated with division of the lower canaliculus. It must be looked for at the earliest under microscope and confirmed by syringing with any colored fluid. Later treatment becomes very difficult. Rarely there may be dislocation of the lacrimal gland.10

Field Testing

Central field by Amsler’s chart and peripheral fields by confrontation test can be done at initial examination. Visual field loss usually indicate visual pathway lesion. More sophisticated tests can be done later if indicated.

Malingering

FUNCTIONAL EXAMINATION

Visual Acuity

It is by far the most important part of eye examination which is usually done first. In trauma cases it may be slightly delayed till the patient settles down. Ideally vision should be recorded in each eye with a standard chart (Snellen/ ETDRS). In many serious injuries the vision is often too low and may be recorded by finger counting, hand movements or perception of light (PL). The last one has to be done very carefully and repeatedly by a strong light (indirect ophthalmoscope). Projection of rays (PR) should also be tested with a pen torch. Visual acuity has great importance in work related injuries, medico-legal cases and in assessing the effect of treatment. In some conditions the vision tends to fluctuate.11 If correcting glasses are not available pin hole vision may be taken. Knowledge of pre-trauma vision is important in assessing the loss.

This is not very uncommon in some trauma patients particularly those who want to avoid their duties or who can get some advantage by compensation. These tests are not very easy and there is a battle of wits between the patient and doctor. However a few tests done carefully can prove malingering.

By following a definite routine in clinical evaluation much information is gained and future strategy for treatment can be chalked out with confidence. The following assessments can be made after a proper clinical evaluation:

a.Open globe or closed globe injury

b.Immediate treatment or reference

c.Prognosis.

It may be added that a properly drawn diagram

is much more useful than written words, hence a few labeled diagram of injury must be drawn.

References

RAPD

It is important to assess afferent pupillary defect by swinging light test. It is affected by optic nerve lesion, gross retinal lesion but rarely by anterior segment lesions.12

1.Harlan JB, Ng EWM, Pieramici DJ. In Kuhn F Pieramici DJ (Eds): Ocular Trauma, chapter 9, p. 52. Thieme Publication: NY, 2002.

2.Shukla B: Epidemiology of Ocular Trauma, Chapter 3, Observation and analysis. Jaypee Brothers Medical Publishers: New Delhi, 2002;32-36.

Introduction

Fact is much different from fiction, fact is reality of life while fiction is hope of life and today the fact is that the rate of incidence of ocular trauma has increased tremendously in this world of modernization due to road traffic accident and many other day-to- day mishaps.

No one starts a day believing that he will sustain trauma to his organ of vision, yet thousands of people are injured each day. The sudden realization that what had been taken for granted is lost and life may be changed forever leads to extreme anxiety for the patient as well for the patient’s family.

The human eye is a delicate, vital organ — and repairing damage to it can often challenge the limits of medical science. Ophthalmologists — those surgeons who specialize in treatment of eye injuries

— must constantly stay abreast of new developments and techniques to keep their skills finely honed.

The significance of eye injuries is obvious to everyone even though the eyes represent only 0.1% of the total body surface, it is through this organ that most of the information reaches the human animal, whether living in a big city or in the wind. A person with ocular trauma has to go through severe initial anxiety, changes in career and lifestyle, impaired quality of life, economical setbacks and occasionally permanent physical disfigurement. Ocular trauma has therefore had a significant socioeconomic impact on both the involved family and on society in general.

In the present era of specialization and superspecialization where many of us deal with only a certain group of disease; most patients who present with complaints of other segment of the eye are not treated but, referred to a colleague. A patient with ocular trauma however need immediate attention and referral is an option only after certain diagnostic or primary first aid therapeutic procedures have been performed.

Ocular trauma cuts across specialities and for that matter a medico either a physician or a surgeon should

have the basic understanding about the initial evaluation, diagnosis and primary management before referring to a qualified ophthalmologist for further management.

A standardized terminology of eye injury is important to fulfill a very basic requirement in medicine to prevent unambiguous communication. An ideal ocular trauma terminology system was introduced by Birmingham Eye. Trauma Terminology (BETT) and satisfies all elements requested by an ideal system.

When confronted with the ocular trauma patient, the initial evaluation always begins with the assessment of the patient. As ophthalmologist in evaluating the eye trauma patient, one should always assess the whole patient, keeping in mind that the person may have sustained non-ocular injuries which may be life threatening and must be addressed first. In such situations, the ophthalmologist should not hesitate to refer the injured patient to trauma center for initial triage. Once it has been determined that the patient is stable, and other serious nonocular injuries have been addressed, a thorough medical/surgical history is taken followed by a more focused ocular history. Key elements include prior surgery, vision prior to the trauma and detailed history of the traumatic incident.

A full examination is carried out in a methodical and rational fashion, beginning with gross external inspection. Visual acuity is measured in each eye separately. Optic nerve function is assessed by testing for relative afferent pupillary defect. Ocular examination is done with help of torch light and followed by detailed slit lamp evaluation without much manipulation of the injured globe. Obvious open globe injury can often be appreciated with a simple pen light examination. Fundus examination should be carried out at the initial setting if the view of the fundus is not precluded secondary to media opacity. Presence or absence of any obvious infection is documented.

Uncooperative and pediatric patients should be examined under anesthesia in a controlled setting involving experienced critical care personnel.

Approach in Emergency

HISTORY

History of the event

Once emergent life or sight threatening conditions are ruled out, complete description of the events sur-

History of Prior Treatment

•Previous treatment for the injury

•Any self-treatment (e.g. use of eye irrigants, compresses, and ocular medications)

•Dosage and duration of therapy (may confound the results of microbiologic culture tests)