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

Figs 5.1A to C: UBM examination of the angle and the iris

be formed. Gonioscopy shows a dehiscence between the ciliary muscle and the sclera, beginning at the scleral spur and continuing to the ciliochoroidal space.

Although cyclodialysis clefts may be visualized by direct visualization during gonioscopy, the attempt may be unrewarding in post-operative and traumatized eyes because of the presence of hazy media, disturbed anatomy and hypotony. When hazy media or abnormal anterior segment architecture prevent or limit adequate visualization during gonioscopy, UBM can be used to differentiate cyclodialysis, angle recession and ciliary body detachment. In addition, the presence of supraciliary fluid and visualization of a connection from the anterior chamber to the supraciliary space confirms the diagnosis of cyclodialysis. Early diagnosis and appropriate management of cyclodiaysis clefts are

Figs 5.2A and B: Zonular assessmentRole of UBM examination. Direct visualization of zonulesDetailed 360o scanning

important because visual recovery may occur with resolution of hypotony and is dependent on its extent and duration.

Disinsertion of the iris root from its insertion into the ciliary body (iridodialysis), pupillary block, peripheral anterior synechiae in the presence of complete hyphema preventing visualization of the anterior chamber, and vitreous prolapse into the anterior segment can also be identified with UBM.

Zonular damage after closed globe injury is not uncommon and its significance is well known to the anterior segment surgeon. The loss of zonular fibres, in association with a traumatic cataract, might result in an unstable lens and with an increased probability of vitreous presentation and in the worst case scenario, loss of lens into the vitreous cavity.

Visualization of zonules requires a careful 360 degree scanning with the long axis of the transducer perpendicular to the zonules and has a significant learning curve. Zonular defects, when present, are seen as abrupt cessation of the bright reflective lines of zonular fibres associated with blunting of the ciliary processes (Figs 5.2A and B).

UBM can also detect small foreign bodies of various compositions, including those missed by computed tomography (CT) or B-scan ultrasound. It is particularly valuable in the detection of small, non-metallic foreign bodies.

Ozdal et al reviewed the indications for performing ultrasound biomicsroscopic examination in 109 patients.3 UBM examinations were preformed for the evaluation of zonules before cataract surgery (49.5%), examination of the anterior segment in the presence

Introduction

Eyelid and adnexal injuries can be a part of multisystem trauma. The basic ABCs of the trauma management should be considered and applied in every trauma patient. This includes securing a patent airway and stabilization of the circulation. Ophthalmic evaluation and management are deferred until more serious problems are addressed.

Once the patient is stable, attention could be directed to the eyelid injuries. The patient should be evaluated for any globe or optic nerve injuries. This may be difficult especially in patients who are unconscious or uncooperative. The eyelid may be swollen and difficult to open, so care should be taken to avoid forceful opening of the eyelid as this may worsen the already traumatized globe.

Evaluation of Lid Injury

HISTORY

Circumstances of the injury can help determine the type and extent of the trauma. The mechanism of injury can give an idea about the depth of the wound as well as the possibility of foreign body presence.

Falling to the grounds or in contaminated places especially of the patient is young to report should raise a high index of suspicion for the presence of foreign bodies especially of organic nature.

Some symptoms can also give a clue about the extent of damage. Drop of vision suggests globe or optic nerve injuries. Presence of diplopia or hypothesia suggests orbital wall fracture. History of any ocular diseases or surgeries should be documented. Any medical problems, topical or systemic medications, drug allergy as well as problems from anesthesia should be known. History of tetanus immunization is essential. If the patient had not tetanus immunization within 5 years, tetanus toxoid 0.5 ml should be administered. If the patient had never been immunized, 250 units of tetanus immunoglobulins are administered.

In case of animal bite, the rabies immunization of the animal and if the animal has been quarantined should be cleared.

EXAMINATION

This should include evaluation of the globe, adnexal tissue, orbit and face. If the patient is conscious and cooperative, visual acuity, pupillary responses, intraocular pressure measurement as well as dilated fundus examination should be performed. Sometimes examination under anesthesia can be done to avoid further globe injuries during manipulation of the eyelid.

The eyelid is examined for the extent of the wound and if it involves the septum, the muscle, lid margin or canaliculus. Canalicular injury is suspected when the injury lies medial to the punctum which is usually laterally displaced compared to the other side or the opposite one. Medial or lateral canthal injuries as well as tissue loss should be ruled out

Evaluation of the orbit includes searching for ocular motility deficit, surgical emphysema, hyposthesia of the check, nose or upper lip in addition to palpable orbital rim fractures. Orbital imaging with CT is requested when orbital wall fracture or presence of foreign body is suspected.

The lid injuries can be associated with face and neck injuries. A thorough examination of head and neck should be carried out and other specialties may be involved in the repair process. All findings should be documented and photographed.

Principles of Wound Repair

The wound should be closed as soon as possible. Yet the repair can be delayed if the patient is systemically not stable or there are more life-threatening injuries. Any globe injuries should be addressed first. Lid wound repair could still be delayed up to 48 hours following trauma without jeopardizing the outcome.

They involve the skin and underlying muscle. It should be emphasized that proper examination of the wound extent is very important as an innocent superficial wound may have a significant underlying injury. Simple wound closure is done with no tension. This could be facilitated by undermining the edges.

Horizontal muscle lacerations will approximate themselves without suturing yet vertical muscle lacerations should be closed with 6-0 Vicryl sutures.

In more complex wounds such as stellate injuries, care should be taken to follow the skin lines as much as possible and avoid shortening of the anterior lamella that may lead to lid retraction. Closure of these wounds is individualized and depends on the site and extent

Fig. 6.1: Lower lid marginal wound with marginal approximating sutures and a suture that involves 90% of the tarsal thickness

Figs 6.2A and B: Lower lid full thickness wound involving the margin in a 5 years child (A). Same eye 10 days after the repair with remnants of the vicrly sutures (B)

Figs 6.3A and B: A 24 years old male with upper lid wound with tissue defect (A). Same eye 3 weeks after repair using Tenzel flap (B)

Fig. 6.4: Lower canalicular injury with a bicanalicular tube inserted first before the repair of the marginal wound

Their injuries are usually associated with canalicular injuries that should be repaired before repairing the severed tendon. The injury may involve any part of tendon. Repair of the cut posterior limb of the tendon is crucial as if not repaired, the lid globe apposition is markedly affected and traumatic telecanthus usually results (Fig. 6.6). It should be put in mind that repair of medial canthal tendon should provide a posterior pull on the medial canthus thus keeping the lid globe apposition and gives a good cosmetic appearance.

By the time of injury repair, either:

i. The two ends of the cut tendon could be identified: In this condition, the tendon is repaired using non-

Figs 6.7A and B: Repair of the medial canthal tendon injury with reattachment to its remnants (A). Reattachment of the avulsed tendon to the intact periorbita (B)

absorbable or wire suture. A horizontal mattress suture is placed in the distal end of the tendon. The two needles are brought from posterior to anterior through the proximal part (Fig. 6.7A). If the proximal part

Burns of the eyelid are rare. They can be due to thermal, chemical or electric current injuries. They usually occur in patients who have suffered significant burns over a large surface area of the body. The first priority is to establish and maintain a patent airway. Once stable, the globe should be properly examined. If the globe is injured, topical antibiotics and cycloplegics are administered. Topical steroids should not be used as they can cause corneoscleral melting. An amniotic membrane scleral shell could be also applied. The lid skin should be covered with a broad spectrum antibiotic ointment Most of these patients are semiconscious or heavily sedated and need proper corneal protection using lubricants. The lids may be swollen and form a protection to the cornea. If this is not the case especially with marked exposure, a large temporary tarsorrhaphy could be performed.

Once cicatricial changes start to develop usually associated with deterioration of the ocular surface condition, early intervention should occur. Early use of full thickness skin grafts or variable types of flaps had been suggested to reduce the ocular morbidity in selected cases.

Introduction

Lacrimal injuries are usually not isolated. They are almost always associated with lid injuries or orbital or nasal fractures. Eyelid, orbital and adnexal injuries can be a part of multisystem trauma. The basic ABCs of the trauma management should be considered and once the patient is stable, it is possible to properly examine the eyelid with the upper lacrimal passages, orbital injuries as well as the associated globe or optic nerve affection. It should be remembered that upper lacrimal drainage system can be involved in chemical or thermal injuries.

Evaluation of Lacrimal Injuries

HISTORY

The conditions of trauma can give an idea about the nature and the extent of injury. Being usually associated with lid or orbital injuries, high index of suspicion should exist to be able to detect lacrimal passage injuries. Lacrimal gland injury is usually rare and may be associated with orbital roof fractures or deep upper lid wound.

Review of medical history is essential as well as drug allergy history of tetanus immunization and problems encountered with anesthesia.

EXAMINATION

Routine systematic examination of the eyelid, globe and orbit should be performed. Canalicular injury is suspected when the injury lies medial to the punctum which is usually laterally displaced compared to the other side or the opposite one. Medial or lateral canthal injuries as well as tissue loss should be ruled out

Lacrimal passage injuries associated with orbital or nasal fractures may be overlooked especially with the edema or ecchymosis. However, associated nasal bone fractures as well as traumatic telecanthus should raise the index of suspicion.

In case of late presentation of lacrimal drainage system injuries, systematic evaluation should be adopted. This includes, evaluation of the conjunctiva for presence of adhesions as well as assessment of the punctual position, direction and patency. Positive regurge test is a sure sign of nasolacrimal duct obstruction. Dye disappearance test show delay as compared to the other side. Probing may show strictures of the canaliculi or fibrosis of the lacrimal sac that usually felt as a soft stop. Irrigation test can show the extent of NLD obstruction. Nasal examination is very important is such cases as a deviated septum resulting from the original trauma may be the reason of the lacrimal passage problems.

Orbital CT whither conventional cuts or in three dimensions can show the fractures sites and their extent as well as associated nasal deformities.. Dacryocystography can show nasolacrimal duct obstructions site and extent.

Proper lacrimal system evaluation is necessary for choosing the treatment protocol.

Wounds Associated with Canalicular Injuries

They can result from direct trauma to medial canthal area or indirectly by avulsive forces caused by trauma to the orbit. They are common with dog bites and midface injuries. Early repair of the canalicular injury is much easier and more successful than late repair or conjunctivo-dacryocystorhinostomy with Jone’s tube.

Canalicular lesions may be missed. They should be suspected in injuries medial to the punctum that may be and may be laterally displacement. The diagnosis is confirmed by direct visualization of the cut edge or passing a probe into the canaliculus.

Repair of canalicular injuries is done under general anesthesia. A stent should be placed through the transected canaliculus. Bicanalicular silicone tube is commonly used. However, some surgeons use monocanalicular tubes. In case of bicanalicular tube use, the severed canaliculus is intubated first. Both

Fig. 7.1: Lower canalicular injury with a bicanalicular tube inserted first before the repair of the marginal wound

are retrieved from the nose. The marginal wound is then repaired and canthal tendon wound is also repaired before tying the silastic tube (Fig. 7.1). After the wound is approximated, the tube is secured by three square knots and left in place for 6 months

(Figs 7.2A and B).

The medial cut end of the canaliculs could be identified under the microscope with high magnification. It can also be identified using injection of a fluorescein dye or vescoelastic material into the sac through the intact canaliculus. Pooling saline in the medial canthal area with injecting air into the intact canaliculus will point at the site of cut canaliculus where the air bubbles. If the wound is ragged freshening of the edges may be helpful. Retrograde intubation using Pigtail probes is better avoided as it can cause a false passage.

If the punctum is lacerated, the medial canaliculus could be marsuplized opened to the conjunctival sac and the lid woundis repaired ignoring the injured punctum and canaliculus.

Lacrimal Sac and Nasolacrimal Duct Injuries

These lesions may be missed as these parts are included in a protective bony structure. A high index of suspicion should be present to anticipate these problems. They are usually associated with nasoethmoidal fractures, sometimes with blow out fractures of the orbit and types II and III Le Fort fractures.

A nasoethmoidal fracture usually results from a force delivered across the nasal bridge and it’s very common in automobile accidents in which the face strikes the dashboard. The nasal bones become fractured and displaced. The lacrimal and sphenoidal bones are usually crushed. They are associated with surgical emphysema. Traumatic telecanthus is usually present in association with lacrimal passage injury.

Figs 7.2A and B: Lower lid marginal wound involving the lower canaliculus (A) After inserting the tube and repair of the wound (B)

If the fracture is detected and repaired, irrigation of the lacrimal system by the end of the repair should be done. If there is a free system irrigation, nothing more is needed to be done. If there is some minor resistance exists, probing and bicanalicular silicone intubation where the tube is left for 3-6 months may be of use.

If these fractures are not detected and corrected, chronic dacryocystitis can occur and needs dacryocystorhinostomy (DCR). It is sometimes associated with excess bone formation in the area of the nasal and lacrimal bone that accentuates the possibly present traumatic telecanthus. This bone can be debulked while performing the DCR. The surgery can be associated with repair of the present telecanthus.

Old Traumatic Lacrimal Passage Injuries

Management of such injuries varies according to the site and extent of obstruction and addressed in a similar way as non-traumatic cases. For example, destruction of the upper lacrimal system especially with chemical injuries and obliteration of the canaliculi usually necessitates conjunctivo-dacryocystorhinostomy (CDCR) with insertion of Lister Johns tube. Chronic dacryocystitis or complete NLD obstruction are treated by conventional DCR.

Blunt trauma to the eye may result in injury to the iris, angle structures, and other intraocular structures. Hemorrhage into the anterior chamber, or hyphema, is common in children. Generally, a projectile that strikes the eyeball produces the hyphema. A great variety of projectile missiles and objects have been commonly found to cause hyphema including balls, rocks, projectile toys, air gun, paint balls, bungee cords, and the human fist. With the increase of child abuse, fists and belts have started to play a prominent role. Boys are involved in three-fourths of cases.

Rarely, spontaneous hyphemas occur and may be confused with traumatic hyphemas. Spontaneous hyphemas are secondary to neovascularization, ocular neoplasms (retinoblastoma), and vascular anomalies (juvenile xanthogranuloma). Vascular tufts that exist at the pupillary border have been implicated in spontaneous hyphema. A traumatic hyphema may be graded by measuring the height of the layered hyphema in the anterior chamber in millimeters. A hyphema is an ocular emergency and should be referred immediately.

History

An exact history of the trauma should be obtained to assess the velocity involved, which in turn may indicate the extent of ocular damage that may have occurred. Inquiry must be made to determine if visual acuity changes occurred immediately after the injury. Flashing lights are often seen at the instant of injury and indicate irritation of the retina, as any message to the brain from the retina is perceived as light. Persistent blurred vision is indicative of a more serious injury. It may indicate blood in the anterior chamber that is suspended in the aqueous humor. Free-floating blood in the anterior chamber can generally not be appreciated by direct ophthalmoscopy. A slit-lamp is necessary to observe the suspended red blood cells in the anterior chamber.

A hyphema may be graded by the following system: grade 1—layered blood occupying less than 1/3 the anterior chamber, grade 2—blood filling 1/3 to 1/2 of the anterior chamber, grade 3—blood filling more than 1/2 but less than the total anterior chamber, and grade 4—total clotted hyphema filling the anterior chamber, often referred to as an blackball or “eight ball” hyphema. Alternatively, hyphemas may be graded by measuring the height of the hyphema in millimeters from the inferior limbus. These grading systems enable the ophthalmologist to monitor the progress of the hyphema resolution.

Secondary hemorrhage associated with traumatic hyphema results in a markedly worse prognosis. Eventual visual recovery to an acuity of 20/50 (6/15) or better occurs in approximately 64% of patients with secondary hemorrhage compared with 79.5% of those in whom no rebleeding occurred. True secondary bleeding into the anterior chamber is indicated by an obvious increase in the amount of blood in the anterior chamber. Secondary hemorrhage occurs in approximately 22% of all hyphema patients (range 7 to 38%). The rate of secondary hemorrhage is Caucasians is between 8- 10%. The incidence of secondary hemorrhage is higher in hyphemas that occupy 50% or more of the anterior chamber.

There are specific complications of traumatic hyphema. They are directly attributed to the retention of blood in the anterior chamber and include posterior synechiae, peripheral anterior synechiae, corneal blood staining, and optic atrophy. Optic atrophy may result from either acute, transiently elevated intraocular pressure or chronically elevated intraocular pressure. Posterior synechiae may form in patients with traumatic hyphema. They are secondary to iritis or iridocyclitis. Posterior synechiae are uncommon in patients treated medically but occur more frequently in patients who have had surgical evacuation of the hyphema. Peripheral anterior synechiae occur frequently in