MECHANICAL GLOBE INJURIES

The conjunctiva, as the most superficial layer of the eye and inner eyelids, is frequently involved in ocular injuries. Although it has little intrinsic structural

strength, it does provide significant protection against low-momentum foreign bodies (see Chapter 24) and chemical agents; careful examination of its entire surface should therefore always be a part of the examination.

EXAMINATION

Penlight

The penlight is used first to inspect the bulbar and palpebral conjunctiva; before opening the lids, ensure that no open globe injury is present (see Chapter 8). Follow the steps outlined below:

•With the patient looking upward, gently evert the lower lid and evaluate the lower bulbar/palpebral surfaces and the inferior fornix.

•With the patient looking downward, raise the upper lids anda inspect the superior bulbar surface.

To examine the superior tarsal conjunctiva, the upper lid needs to be everted:

•grasp the lashes gently;

•place a small instrument (e.g., cotton-tipped applicator) on the skin of the upper lid at the location of the lid crease;

•with gentle posterior pressure from the applicator handle and anterior traction on the lashes, the lid can be everted and the applicator handle removed; this results in more patient comfort and in a flatter palpebral surface (see Fig. 13–1).

a Press against bone, not the eye ball, when elevating the upper lid.

FIGURE 13–2 Double eversion of the upper lid. To visualize the fornix, the everted upper lid must be further lifted away from the globe. Here a Desmarres lid speculum is inserted behind the tarsal plate to allow inspection of the superior fornix and bulbar conjunctiva.

To inspect the superior fornix move the upper lid anteriorly, away from the globe, with an instrument (double eversion, see Fig. 13–2). A small dental mirror may be helpful.1

PEARL... Double eversion of the upper lid is required to inspect the supe-

rior fornix.

Slit-lamp

Slit-lamp evaluation of the conjunctiva proceeds similarly to the penlight inspection. Using medium-power magnification, the entire conjunctival surface should be examined for foreign bodies, lacerations, or areas of epithelial loss. The upper lid should be everted and the superior palpebral surface also inspected.

It appears as a bright red patch of conjunctival tissue with distinct or feathered borders (Fig. 13–3A). If it is severe, the conjunctiva may become elevated and prolapse through the palpebral fissure; the entire bulbar conjunctiva may be involved (Fig. 13–3B). Generally resolving spontaneously in 7 to 10 days, its color evolves from bright red to yellow green. Occasionally, when the hemorrhage involves the perilimbal conjunctiva, blood breakdown products can be seen in the anterior peripheral corneal stroma as a greenish discoloration.

Hemorrhage under or into the conjunctiva can occur:

•as a result of even minor ocular trauma;

•spontaneously; or

•in association with a variety of conditions including Valsalva maneuvers (see Chapter 33), primary conjunctival amyloidosis,3 inverted positioning,4 dancing;5 and, by far the most common, systemic hypertension.b

The management of a traumatic subconjunctival hemorrhage is hopeful expectancy, although it must

b The subconjunctival hemorrhage may be the first sign of hypertension2 ; consequently, the blood pressure should be checked in all patients with spontaneous subconjunctival hemorrhage.

be ensured that the hemorrhage does not indicate or conceal a deeper or more extensive injury.

P I T F A L L

The presence of subconjunctival pigmentation in association with a hemorrhage is very suspicious of occult scleral rupture. The examiner must obtain a complete ocular history and perform an examination on all patients presenting with traumatic subconjunctival hemorrhage to rule out occult scleral wound or laceration with or without an IOFB (see Chapters 9 and 24).

Foreign Bodies

Conjunctival foreign bodies are common (Fig. 13–4). Because they may also indicate the possibility of deeper, more invasive injury, this must always be ruled out.c Most conjunctival foreign bodies can easily be removed with either a cotton-tipped applicator or a 30-gauge needle.

PEARL... Removal of foreign bodies from the upper lid’s conjunctival surface is a great relief for the patient as these objects

scratch the cornea (twice) with each blinking.d

CHAPTER 13 CONJUNCTIVA • 91

•Fine forceps (e.g., jeweler’s) are helpful if the object is tightly adherent to the conjunctival surface or is slightly imbedded.

•If the foreign body is deeply imbedded, the overlying conjunctiva may need to be opened to facilitate removal. Following removal, a topical antibiotic ointment should be applied.

Some small nonreactive particulate objects can be left in place without complications, while certain deeply embedded foreign bodies (e.g., small metallic or glass fragments) will work themselves out with time.

PEARL... Not all conjunctival foreign bodies are a result of involuntary trauma (e.g., self-introduction of foreign material into

the fornix as a form of Munchausen syndrome6).

Lacerations

Lacerations may be isolated injuries or signal deeper trauma. It is imperative that all patients with conjunctival laceration have a thorough and extensive examination (including dilated fundus evaluation) to rule out conclusively an open globe injury. In case of true IOFBs, the findings may be subtle and limited to a barely visible conjunctival lesion.

cThe foreign body may be partially intraocular (see Fig. 13–5).

dIt is pathognomical so see vertical lines of epithelial defect on the cornea.

PEARL... The scleral wound rarely lies directly underneath the conjunctival deficit (see Fig. 13–5): in most cases, the patient is not in primary gaze at the time of injury. The scleral defect may even be at a significant distance from the site of the conjunctival lesion. Examining the eye in a variety of gazes and gently moving the anesthetized conjunctiva with a moistened cotton-tipped applicator help make the diagnosis; caution should be taken not to put pressure on the globe. If necessary, exploration should be performed under local anesthesia; if a scleral wound is appreciated or strongly suspected, this should be attempted only in the

operating room.

Treatment of small lacerations involves only antibiotic ointment. Larger lacerations may require closure. Rapidly absorbable suture materials (e.g., chromic or plain gut) are adequate for most cases. Tissue healing is rapid and rarely is there sufficient tension on the conjunctiva during closure to require anything more than simple wound edge apposition.

Swelling of the conjunctiva is a primary dysfunction of its vascular endothelium, signaling a common response to a variety of injuries or noxious stimuli:

•inflammation;

•increased orbital pressure as in orbital congestion from contusion; or

•increased venous pressure in the setting of carotid cavernous fistula.

Although some chemosis is present in most cases of ocular trauma, its degree at the time of the initial evaluation is not a good indicator of the severity of the trauma; for example, severe alkali injuries may cause only minimal chemosis initially.

P I T F A L L

In contusions with orbital congestion, especially when associated with subconjunctival hemorrhage, the resultant conjunctival chemosis may be sufficient to obscure the examiner’s view of the globe.

FIGURE 13–6 Conjunctival emphysema. Individual air bubbles may be visible and the conjunctiva is frequently regionally involved.

Emphysema

Emphysema occurs when free air gets trapped under or in the conjunctiva (Fig. 13–6). The air can be from an internal source (endogenous) or an external source (exogenous). Endogenous emphysema is much more common, occurring in the setting of orbital fracture: an access route from the paranasal sinuses to the orbit is created. With nose blowing, coughing, or other forced exhalation, air is driven into the orbit and dissects anteriorly under and into the conjunctiva. This may result in conjunctival emphysema with very sudden and impressive exophthalmos.7 Explosion is the most common source of exogenous emphysema.

PEARL... Patients with orbital fractures should be cautioned against nose blowing or sneezing with a closed mouth so as to

avoid orbital and subconjunctival emphysema.

In exogenous emphysema,8–11 unless the stream of air is under very high pressure or associated with high-pressure fluid, the proptosis is a less prominent component than with endogenous emphysema. Conjunctival defects or lacerations are extremely uncommon in this setting.11

CHAPTER 13 CONJUNCTIVA • 93

PROGNOSIS AND OUTCOME

The prognosis for the vast majority of conjunctival injuries is excellent. The conjunctiva heals rapidly and, due to its rich blood supply, infections are rare. Prognosis is more guarded for chemical injuries, however, as destruction of the conjunctival vascular supply and the corneal limbal stem cells may result in permanent ocular surface changes with corneal ulceration and long-term scarring and vascularization (see Chapters 11 and 32). In addition, destruction of the specialized cellular components of the conjunctival surface may permanently change the composition of the preocular tear film with unfortunate sequelae for the corneal surface.

THE NONOPHTHALMOLOGIST’S ROLE

Most of the minor conjunctival injuries can be managed by the nonophthalmologist.

PEARL... The most important caveat is to recognize when the seemingly innocuous subconjunctival hemorrhage conceals a deeper injury. A complete evaluation of the eye and adnexa must be performed to ensure that the full extent of the injury is recognized and appropriate testing and treatment are

undertaken.

SUMMARY

The conjunctiva is a frequently injured ocular structure. If the injury is isolated to the conjunctiva the prognosis is often excellent and rarely requires surgical intervention. The most important aspect of conjunctival injury is that it may signal the presence of more serious ocular trauma.

1.Duke-Elder S. System of Ophthalmology. Vol VII. St. Louis: CV Mosby; 1962:239.

2.Fukuyama JI, Hayasaka S, Yamada K, Setogawa T. Causes of subconjunctival hemorrhage. Ophthalmologica. 1990;200:63–67.

3.Lee HM, Naor J, DeAngelis D, Rootman DS. Primary localized conjunctival amyloidosis presenting with recurrence of subconjunctival hemorrhage. Am J Ophthalmol. 2000;129:245–247.

4.Caspari RF. A “new wave” of subconjunctival hemorrhage [letter]? N Engl J Med. 1980;303:1420.

5.Friberg TR, Weinreb RN. Ocular manifestations of gravity inversion. JAMA. 1985;253:1755–1757.

6.Cruciani F, Santino G, Trudu R, Balacco Gabrieli C. Ocular Munchausen syndrome characterized by self

introduction of chalk concretions into the conjunctival fornix. Eye. 1999;13(pt 4):598–599.

7.Hunts JH, Patrinely JR, Anderson RL. Orbital emphysema. Staging and acute management. Ophthalmology. 1994;101:960–966.

8.Biger Y, Abulafia C. Subconjunctival emphysema due to trauma by compressed air. Br J Ophthalmol. 1986;70: 227–228.

9.Li T, Mafee MF, Edward DP. Bilateral orbital emphysema from compressed air injury. Am J Ophthalmol. 1999;128:103–104.

10.Hitchings R, McGill J. Compressed air injury of the eye. Br J Ophthalmol. 1970;54:634–635.

11.King YY. Ocular changes following air-blast injury. Arch Ophthalmol. 1971;86:125–126.