Eye

Eye


Petros E. Carvounis and Yvonne I. Chu


EPIDEMIOLOGY OF EYE TRAUMA


Worldwide 1.6 million people are estimated to be blind from ocular trauma and another 19 million people suffer from severely impaired vision in one eye due to trauma.1 Published literature from England looking at 15 years of more than 39,000 patients treated for major trauma found that 2.3% of patients had associated ocular injuries. Given that the eyes represent only 0.27% of the total body area, it is a curious phenomenon that the eyes are affected so often. In this series, the most common injuries involved the cornea, optic nerve, conjunctiva, and sclera.2


Men are reported to be four times more likely to suffer from ocular trauma compared to women and in the same series from England, 75.1% of major trauma patients with ocular injuries were men. While ocular trauma most commonly results from motor vehicle accidents, workplace injuries and recreational injuries are also very commonly seen. Most injuries were resulting from sharp objects (54.1%), followed by blunt objects (34.4%), and chemical injuries accounted for 11.5% of ocular injuries.3


EYE TRAUMA TERMINOLOGY AND CLASSIFICATION


Eye trauma is divided first by etiology into mechanical, chemical, thermal, and electric. Thermal (e.g., corneal burn from curling iron) and electric (e.g., lightning) eye traumas are very uncommon and treatment of complications will be by an ophthalmologist in an outpatient setting after discharge from the emergency room/urgent care setting. Chemical injury (alkali and acid burns) is not uncommon and its management will be discussed in detail as immediate intervention by first responders and emergency room physicians can be sight-saving.


Mechanical eye trauma is the most common form of eye injury. It is divided into open globe injury, where the sclera and/or cornea (eyewall) have a full-thickness wound, and closed globe injury where the eyewall does not have a full-thickness wound (Fig. 20-1).46 Closed globe injuries are further subdivided into contusion injuries, lamellar laceration (i.e., partial thickness laceration), and superficial foreign body (i.e., foreign body lodged on cornea, conjunctiva, or under the conjunctiva but without full-thickness wound of the eyewall).6 Open globe injuries are further divided into ruptured globes and globe lacerations.4,5 Ruptured globes result from blunt trauma, due to an extreme elevation of intraocular pressure on the moment of impact causing a rupture of the eyewall at the weakest site of the globe (force from inside out), usually away from the site of impact and frequently with significant herniation of intraocular contents.46 Globe lacerations result from sharp trauma (usually) due to the direct impact on the eyewall (force from outside inwards).4,5 Perforating injury is a specific type of globe laceration in which the projectile or sharp object has caused an entry as well as an exit full-thickness eyewall wound.4,5 In a penetrating injury only a single full-thickness eyewall wound is present per projectile/object (there is no exit wound).4,5 Finally, an intraocular foreign body (IOFB) is a type of penetrating laceration in which the foreign object is retained within the globe.46


image


FIGURE 20-1 Injury classification.


The above classification is not simply an academic exercise. It provides an effective means of communication between treating physicians but even more importantly the exact type of injury has specific implications to management and prognosis.46 Specifically, an open globe needs urgent operative repair, whereas a closed globe typically does not. Among open globes, globe rupture portends a poorer prognosis for final visual outcome than globe laceration.7,8 Finally, an IOFB is usually best removed by a vitreoretinal surgeon and may require vitrectomy (sometimes not available in general ophthalmology operating rooms), whereas a penetrating or perforating injury can be managed by any ophthalmologist in an operating room with an ophthalmic operating microscope. Certainly in needed circumstances, primary closure can be achieved and the patient can be referred to a retina specialist for removal of an IOFB at a second procedure.


CLINICAL APPROACH TO EYE TRAUMA


It is imperative that concomitant nonocular injuries be evaluated and assessed on presentation to the emergency room. Involvement of the ophthalmologist in a timely manner and in the absence of life-threatening injury before transfer to the operating room is important. Sight-threatening injury needs to be recognized and treated within an appropriate time interval.


image History

Every effort should be made to take a focused history—if not from the patient (if he or she is unconscious, distracted by other severe injuries, or under the influence of alcohol or drugs), then from relatives, bystanders, or first responders. In the setting of trauma, being time efficient is obviously of the utmost importance.


The most important aspect of the history is the mechanism of injury, as specific mechanisms suggest specific injuries that must be assessed for and treated. For example, hammering is associated with intraocular metallic foreign bodies, while fireworks injury is commonly associated with chemical injury that must be treated emergently (as well as contusion injury—rarely open globe). Injury to the forehead as a result of a bicycle accident followed by loss of consciousness is a common scenario in which traumatic optic neuropathy may develop, while injuries from BB guns are associated with globe lacerations with particularly poor prognosis. Additionally, it is important to elucidate the setting of the injury: penetrating injuries in a rural setting are associated with higher rates of endophthalmitis. Documenting whether protective eyewear was worn at the time of the injury is important for medicolegal reasons.


Patient symptoms are also important: floaters and a visual field defect are highly suggestive of a retinal detachment, while pain with sensitivity to light without compromise in the vision suggests a traumatic iritis (although a globe laceration and even an IOFB remain a possibility).


Past ocular history is important for two reasons. First, it may modify the effects of trauma, for example, in the case of a patient who has previously had a corneal transplant an open globe due to dehiscence of the graft will occur with much less force than normally expected. Similarly, in patients with previous cataract or glaucoma or radial keratotomy surgery the globe ruptures at the site of the previous wound. Second, past ocular history is important as preexisting pathology may dictate different treatment decisions following trauma. For example, the threshold for surgical evacuation of a hyphema would be much lower in a patient with advanced glaucomatous optic neuropathy than in a patient with healthy optic nerves.


Past medical history is similarly important as it can modify treatment decisions. For example, hyphema is managed differently in patients with sickle cell disease. Another example would be patients with pseudoxanthoma elasticum who invariably have angioid streaks and have a much higher risk of choroidal rupture. There are also several systemic conditions that result in eye conditions unrelated to trauma, an obvious example being diabetes mellitus causing diabetic retinopathy that can cause nontraumatic vitreous hemorrhage.


Important aspect of the drug history is whether the patient is on anticoagulants or antiplatelet agents as this will complicate operative repair. Additionally, determining allergies to medications is critical.


Review of systems must assess for the patient’s ability to survive anesthesia and surgical repair. Patients who cannot undergo surgery safely may be better managed medically even though the risk of losing their sight in one eye is evitable rather than dying from complications of anesthesia.


image Clinical Examination

Clinical examination can be challenging due to pain or poor patient cooperation due to the influence of alcohol, drugs, or severe eyelid swelling; yet it is essential for proper diagnosis and management of ophthalmic trauma. The basic tool kit needed for rudimentary eye examination includes: penlight, near vision card, eyelid retractor/speculum, topical anesthetic, fluorescein strip, and eye wash.


Visual Acuity

It is no exaggeration to state that failure to document the visual acuity is inexcusable and akin to failure to document the pulse! Measuring visual acuity is crucial for three reasons. First, a specific level of vision prompts the examining physician to search for a diagnosis explaining it. For example, vision of hand motions only (HM) is not explained by a subconjunctival hemorrhage and requires the examiner to carefully examine for the other signs of a scleral rupture. Another example would be the patient who had trauma 3 days previously and presents to the emergency room with photosensitivity, mild lid edema, and vision of 20/400: before knowing this level of vision, traumatic iritis could have been contemplated but with vision of 20/400 endophthalmitis with a self-sealed corneal or scleral laceration becomes a strong possibility.


The second reason it is important to measure the visual acuity is to document a baseline so that later in the course it can be established whether there is improvement or deterioration. For example, a patient with a vitreous hemorrhage and vision of HM is seen by a vitreoretinal surgeon for examination to rule out retinal tears and detachment; if a week later the vision is 20/200 (and there are no retinal tears or detachment), further observation is reasonable as it appears that the vitreous hemorrhage is spontaneously resolving. In contrast, if a week later the vision is light perception, this suggests that a retinal detachment has occurred due to an undetected retinal tear.


The final reason why it is important to measure visual acuity is that visual acuity at presentation is a strong predictor for final visual outcome.7,8 Therefore, having an initial visual acuity is essential if discussing the prognosis of the injury with the patient.


Measuring visual acuity is relatively easy. Obviously each eye is tested separately by covering the other eye with an occluder (or the patient’s hand if there is no occluder available). The goal is to determine whether the patient has no light perception (NLP—cannot even see the light from a strong pen torch right in front of the injured eye with the room darkened), light perception only (LPO—can see the light but no hand movements), HM (can see hand movements but cannot count fingers), or vision between 1/200 and 20/20. When trying to measure vision between 1/200 and 20/20, the patient should be wearing his or her spectacles (if these are available). Counting fingers at a distance x is equivalent to x/200 (e.g., counting fingers at 2 ft is vision of 2/200). For vision better than 5/200 a Rosenbaum reading card or a Snellen or ETDRS visual acuity chart can be used. If none of these are available, documentation of ability to read the newspaper title (approximately 20/200) or the normal magazine print (approximately 20/40) is still extremely helpful.


Pupillary Examination (Shape, Reaction, and Relative Afferent Pupillary Defect)

The pupil may be peaked if there the iris is sealing (plugging) a corneal or anterior scleral laceration. The pupil may also be irregular if there has been injury to the iris sphincter muscle (typically a result of blunt trauma, commonly associated with hyphema).


The pupil will be dilated and not react to light if there is compression or damage to the third cranial nerve intracranially (following head trauma); if this is suspected, urgent neurosurgical consultation and computed tomography (CT) imaging is required. Additionally, an orbital compartment syndrome (due to retrobulbar hemorrhage or any cause for swelling within the orbit) may cause compression of the third nerve (and all the other nerves) and result in a fixed dilated pupil. Finally, if there has been damage or ischemia of the iris sphincter (very elevated intraocular pressure or torn iris sphincter), the pupil will not react to light.


A relative afferent pupillary defect (RAPD) is important to document for two reasons: first, its presence means that there is injury to the retina or optic nerve. This is important as it prompts the examiner to carefully consider the diagnoses that may be affecting the retina and optic nerve and not satisfy himself or herself with a diagnosis involving the anterior segment only. Second, the absence of an RAPD is a strong predictor of visual survival, with only 97% of eyes without an RAPD maintaining some vision.9


Measuring an RAPD is by alternately shining a strong light to each eye. At least 2 seconds should be spent shining each eye with 1 second in transit. When the pupils dilate when the light is shone into one of the eyes, it is said that an RAPD is present in that eye. It is important to note that it is the first movement of the pupil when the light is shone into it that matters. From the above, it should be obvious that even in a patient with a pupil that is immobile in the injured eye determination of the presence or absence of an RAPD in that eye is possible since the contralateral pupil movement can be observed while shining the light into the injured eye.


Motility

Examination of motility is important to rule out cranial nerve 3–6 injury in head trauma and also to detect muscle entrapment following an orbital fracture (typically inferior rectus muscle entrapment causing a deficit in elevation following an orbital floor fracture—in children this can be associated with severe, even life-threatening bradycardia due to the oculocardiac reflex).


Examination of motility is by asking the patient to follow an extended second digit or pen in all directions of gaze. It is important to ascertain whether the patient has diplopia when looking at any of these directions.


External and Ocular Adnexal Examination

Examination of the ocular adnexa involves looking at the eyelid position with eyes both open and closed, contour, and evidence of laceration. It is important to also evaluate for proptosis and in patients with proptosis, testing for resistance to retropulsion may point toward elevated intraocular pressure and congested orbital compartment. As part of the routine external examination, the examiner should palpate the orbital rim for “step off” in cases of suspected orbital fractures. In cases of suspected orbital floor fractures, testing sensation along the distribution of cranial nerve V on either cheek can be an early sign.


Slit Lamp Biomicroscopy

The slit lamp biomicroscope is the ideal instrument to examine the anterior segment. Portable versions exist for patients who cannot sit up to be examined with the regular slit lamp. If not even a portable slit lamp is available, a direct ophthalmoscope offers high magnification and can be used, and if even this is unavailable, a penlight with a blue filter and a magnifying lens can be used.


Throughout the examination of the anterior segment it is important to remember that pressure should not be exerted on the globe (as it may be open and it is uncomfortable to the patient)—rather the lids should be lifted and held up by applying pressure against the orbital rim.


Examination of the anterior segment starts with inspection of the conjunctiva and sclera. Subconjunctival hemorrhage is a common finding sometimes even after trivial trauma, but can be a sign of an open globe; therefore, the other signs of an open globe should be sought. Additionally, a subconjunctival hemorrhage can be a sign of a retrobulbar hemorrhage, especially if its posterior margin cannot be defined; therefore, the other signs of this condition should also be sought. Uveal tissue, vitreous gel, or even retina is sometimes evident on or under the conjunctiva in cases of scleral rupture or laceration.


Inspection of the cornea should be performed actively searching for a corneal laceration, a corneal foreign body, a corneal abrasion, and a corneal concussive injury to the endothelium (appears as opacity on the endothelium). A corneal abrasion may be more easily seen by applying fluorescein drops or a fluorescein strip in the tear lake and using the cobalt blue filter.


Examination of the anterior chamber should be performed looking for hyphema, hypopyon (layering of white cells inferiorly diagnostic of endophthalmitis in the setting of trauma), a shallow anterior chamber suggestive of open globe, an anterior chamber foreign body, and anterior chamber cell (white cells in the anterior chamber—are seen in endophthalmitis or traumatic iritis). Examination of the iris should be performed looking for iris tears or iris dialyses.


Finally, examination of the lens should be performed to determine whether it is present or not (it may have been lost in the case of a corneal laceration with extrusion of ocular contents or in the case of rupture at the site of prior cataract surgery with extrusion of the intraocular implant), whether it is subluxed, whether there is an intralenticular foreign body, or whether cataractous changes have developed.


Intraocular Pressure

There is no need to check the intraocular pressure if the globe is obviously open, but if not, measurement of the intraocular pressure is mandatory. Intraocular pressure is best measured using a Goldmann applanation device used with the slit lamp, but a Tono-Pen is a convenient device for use in the emergency room setting.


A high pressure can be seen with hyphema or with a retrobulbar hemorrhage (due to transmission of the elevated intraorbital pressure), while a low pressure is seen with an open globe or severe intraocular inflammation. It should be noted, however, that the intraocular pressure may on occasion be normal (rarely high) with an open globe.


Dilated Fundoscopy

Dilated fundoscopy is best performed using indirect ophthalmoscopy, a skill beyond the remit of a trauma surgeon. However, a direct ophthalmoscope can establish whether the view is clear or not (if not, either there is a problem with the cornea, anterior chamber, or lens or there is a vitreous hemorrhage), can detect a choroidal rupture and commotio retinae, or can document a normal posterior pole examination. Any patient with a vitreous hemorrhage needs indirect ophthalmoscopy for detection of retinal tears or peripheral retinal detachment.


image Ancillary Studies

B-mode ultrasonography is very useful for examination of the posterior segment in the presence of media opacities not allowing ophthalmoscopy. Retinal tears, detachments, and IOFBs can be detected. It should be noted that the investigation is strongly operator dependent and that even in experienced hands severe vitreous hemorrhage cannot be reliably distinguished from a retinal detachment.10


CT imaging is important in evaluating for orbital fractures, orbital foreign bodies, and IOFBs, especially metallic. An orbital CT scan with thin slices should be ordered. Note that the dimensions of foreign bodies are commonly exaggerated on CT images.10 It should also be noted that vegetable matter (such as wood) in the orbit is not well imaged by CT.


image Initial Management of the Patient with Ocular Trauma

After the patient is stabilized (i.e., life-threatening injuries have been stabilized) other organ-threatening injuries need to be managed in parallel to evaluating the injured eye. The following are priorities when managing the injured eye:


1. Rule out a chemical injury by history (splash of liquid into the eye, explosion at chemical facility, firework injury). If there is suspicion of a chemical injury, a pH strip should be checked (from the fornix) and irrigation should be started at once (see Section “Chemical Injury”).


2. Rule out an open globe if possible: look for the specific signs (corneal/scleral laceration, prolapse of uveal tissue, hemorrhagic chemosis of the conjunctiva, low intraocular pressure, asymmetry in anterior chamber depth, vitreous hemorrhage). If there is reasonable suspicion of an open globe, exploration in the operating room should still be carried out (such as appendectomy; while one endeavors to reduce the rate of negative exploration, it is better to have a negative exploration than to miss the diagnosis). If there is an open globe or an open globe is suspected:


a. The patient needs urgent (as soon as possible and certainly within 12 hours) repair in the operating room by an ophthalmologist—the necessary arrangements need to be made (this may include transfer to a center with an operating microscope and available ophthalmologist, ophthalmology consult, etc.). Certainly a nil per os (NPO) order needs to be written and intravenous fluids started.


b. Place a shield to cover the eye and instruct the patient not to squeeze his or her lids or strain as this may cause further extrusion of intraocular contents; if a metal shield is not available, a cut Styrofoam cup may be taped over the eye. When taping the shield, it is important that the edge of the shield is secure over the orbital rim (i.e., make sure it is not pressing against the globe).


c. Order a CT scan to rule out an IOFB if the mechanism of injury suggests this is a possibility.


d. Administer tetanus toxoid.


e. Intravenous fluoroquinolone antibiotic (moxifloxacin, levofloxacin, or ciprofloxacin) needs to be considered in penetrating injury, especially when this occurred in a rural setting or if an IOFB is present.


f. Repair of lid lacerations or orbital fractures should never be undertaken before an open globe has been ruled out or repaired.


3. Identify other orbital or ocular injuries and treat accordingly (see Section “Specific Injuries and their Management”).


PROGNOSIS OF EYE TRAUMA


Prognosis of eye trauma involves discussion of three entities: whether the patient is going to retain his or her globe, what the patient may expect his or her vision to be in the long term, and finally whether this will affect the uninjured eye (see discussion on sympathetic ophthalmia below).


Whether a patient is going to retain his or her globe depends on the specifics of the traumatic injury. It is rare that enucleation will be required for an eye sustaining an injury other than an open globe. Primary enucleation is rare (0.17% of open globes) and reserved for eyes where the sclera and cornea have been injured so severely that they cannot be sutured back together (usually due to a blast injury where the eye has been blown away or a gunshot injury directly to the eye).11 Secondary enucleation (reported in 6–20% of open globes) is much more common for ruptures than lacerations and is usually performed for a blind (NLP), painful eye.7,9,11,12 An RAPD, NLP or LPO, visible uveal tissue, and concomitant eyelid laceration at presentation are risk factors for enucleation.7,11,12 Enucleation to prevent sympathetic ophthalmia is also sometimes performed, although it is controversial (see below).


The best system that predicts long-term visual outcome (after appropriate management including surgical treatment) is the ocular trauma score (OTS).8,13 In the OTS a functional outcome (initial visual acuity) and five signs or diagnoses (rupture, endophthalmitis, relative afferent papillary defect, retinal detachment, perforating injury) are used to estimate the likely visual outcome (Table 20-1).8


TABLE 20-1 Determination of Ocular Trauma Score


image


Many patients worry that a poorly seeing eye will cause “straining” of the other eye—this is unequivocally nonsense. However, the uninjured eye may develop sympathetic ophthalmia, a rare (incidence 0.03/100,000 per year),14 bilateral uveitis that may occur 2 weeks to 50 years usually following eye trauma or surgery.15,16 While originally described as a consequence of trauma, currently it is more common following eye surgery.14 This is a consequence of improved management of ocular trauma, including prompt primary repair. Indeed, most cases with sympathetic ophthalmia following eye trauma present to the ophthalmologist several weeks after the initial trauma when the vision in the second eye is affected.17 Tellingly, since World War II there had been no cases of sympathetic ophthalmia reported in any military conflict until a single case in the recent war in Iraq.15 With current treatments, eyes affected with sympathetic ophthalmia commonly maintain functional vision with the majority maintaining reading vision.18 While removing the injured eye (when the vision is NLP) may decrease the rates of sympathetic ophthalmia, this is quite controversial given that sympathetic ophthalmia is rare (especially with appropriate management of the injured eye) and treatable.


SPECIFIC INJURIES AND THEIR MANAGEMENT


image Chemical Injury

Chemical injuries to the eye are true ocular emergencies and time is of essence when treating acute chemical exposure. They represent 7.7–18% of ocular trauma.1921 Immediate and copious irrigation is vital to limiting the extent of damage to the ocular surface. Alkaline agents tend to penetrate the eye more rapidly due to saponification of cell membranes and lead to liquefactive necrosis. Acidic agents cause coagulative necrosis with protein precipitation within the tissue; thus, acidic injuries tend to cause less severe injury compared to alkali agents due to less penetrative damaging effects.22 The nature of the toxic agent should be identified and brought into the emergency center if possible so that pH can be tested.


Following toxic chemical exposure to the ocular surface, irrigation should begin immediately with water, saline, or any commercially available eyewash with a neutral pH, and continued if possible while en route to the nearest emergency center. On arrival to the emergency center, an initial pH should be taken by placing pH testing paper in the inferior fornix. Irrigation should continue until the measured pH is neutral (7.2–7.4) for at least 5 minutes after irrigation has stopped. It is important to note that irrigation can last up to an hour or more depending on the severity of the splash injury in order for the eye’s pH to normalize.


Irrigation can be performed by directly pouring saline from intravenous tubing to the surface of the eye. Placing one drop of topical ophthalmic anesthetic such as proparacaine may help the patient to keep the affected eye open. Caution should be exercised when placing irrigation lenses such as a Morgan lens since retained particulate matter or foreign body can be trapped in the fornices of the eye. If an irrigation lens is to be used, the superior eyelid should be everted to look for embedded foreign body and both the superior and inferior fornices should be swept clean with a moist cotton swab to remove any particulate matter.


Chemical injuries are classified using the Roper-Hall classification system (Table 20-2). The size of the corneal epithelial defect and the clock hours of limbal ischemia should be documented after cessation of irrigation by drawing a circle to represent the cornea. Corneal epithelial defects can be easily detected using topical fluorescein staining, such as a moistened fluorescein strip or manufactured combination of fluorescein and topical anesthetic eye drops. Limbal ischemia appears as blanching of normal conjunctival and limbus blood vessels. Hyperemia in the setting of chemical injury presents better prognosis than a white eye.


TABLE 20-2 Classification of Severity of Ocular Surface Burns by Roper-Hall


image


Successful management of chemical ocular injury is to stop ongoing tissue degradation, promote reepithelialization of the surface, minimize inflammation, and prevent infection. For grade 1 damage, the patient can be treated with an antibiotic (e.g., erythromycin) or antibiotic/steroid mixed combination eye ointment (e.g., dexamethazone/polymyxin/neomycin) four times a day to the affected eye and a topical cycloplegic agent (e.g., atropine) to decrease ciliary spasm and decrease formation of posterior synechiae.22 For grade 2, topical steroid eye drops may need to be added to the regimen to decrease the inflammatory response for the first 1–2 weeks postinjury. In grades 3 and 4, high-dose vitamin C, 10 ascorbate eye drops, and 10% citrate eye drops have been associated with more rapid recovery and better vision.23 Oral doxycycline is a collagenase inhibitor and may reduce the risk of corneal thinning and perforation in severely burned eyes.24,25


Consultation with an ophthalmologist is necessary for follow-up and ensuring that the treatment regimen is leading to clinical improvement. Rarely is immediate surgical intervention needed in chemical injury patients.


MECHANICAL INJURY


image Subconjunctival Hemorrhage

Subconjunctival hemorrhage is a very common condition that presents as an ocular emergency. Clinically, subconjunctival hemorrhages appear as flat, bright red blood noted under the bulbar conjunctiva (Fig. 20-2). It can be alarming in appearance and although severity can be variable, in general, it is rather benign and poses no threat to vision.


image


FIGURE 20-2 Subconjunctival hemorrhage.


Spontaneous subconjunctival hemorrhage can be due to Valsalva maneuvers, coughing, sneezing, vomiting, or heavy lifting. Minor trauma such as excessive eye rubbing can also cause subconjunctival hemorrhages. Often, no specific etiology can be found. When subconjunctival hemorrhage is noted with other signs of facial or ocular trauma, one must rule out occult globe injury. Obtaining a good history is vitally important to determining if further workup is needed. A history of blunt trauma may present with subconjunctival hemorrhage but the patient may also have orbital fractures that need to be evaluated.


Patients who present with complete 360° of subconjunctival hemorrhage from blunt trauma should be examined by an ophthalmologist to rule out possible occult scleral rupture or open globe injury. Clues that may indicate occult open globe injury include: peaked pupil, asymmetric anterior chamber depth, asymmetrically low intraocular pressure, and subconjunctival pigment.


In cases of isolated subconjunctival hemorrhage, no treatment is needed. The hemorrhage will usually resolve spontaneously in a few weeks. Patients need to be informed that the hemorrhage will change color over the next few days and may expand as the bruising process evolves. These patients typically do not require ophthalmic follow-up.


image Conjunctival Lacerations

Conjunctival lacerations may present in isolation or in combination with damage to deeper layers of the eyewall and the sclera. Isolated conjunctival lacerations do not require surgical repair unless they are large (e.g., >2 cm) or lie over an extraocular muscle insertion. Often it is difficult to assess if the sclera is involved without manipulation using a cotton tip swab to gently push away the conjunctiva exploring the scleral wall beneath. For large conjunctival lacerations or those that may involve the sclera, ophthalmic consultation is warranted.


Scleral penetration can be associated with vitreous hemorrhage and if the scleral defect is large enough, vitreous prolapse can be seen as well. If there is vitreous hemorrhage, the patient’s vision may be compromised. It is important to not engage the vitreous prolapsed through a scleral defect since traction on the vitreous strands can lead to retinal tears leading to rhegmatogenous retinal detachments.


Corneal Abrasion

Patients with corneal abrasions typically present with intense pain and photophobia. Trauma to the cornea from a fingernail, paper cut, thrown objects, and contusive injury (e.g., air bag) can result in the superficial corneal epithelium being stripped away from the underlying stroma. Simple corneal abrasions can be one of the most painful injuries that patients experience because beneath the corneal epithelium lies an extensive plexus of sensory nerves from the ophthalmic division of the trigeminal nerve and when they become exposed, severe pain results.


Corneal abrasions can be diagnosed clinically when topical fluorescein dye is taken up by the area devoid of epithelium and turns bright green viewed with a cobalt blue light. The size and location of the abrasion can be documented using a circle to represent the cornea. Traditional teaching advocated patching for corneal abrasions in the past. Currently, evidence shows that patients heal faster without patching, and also with patching, there is no benefit with regards to pain reduction. Small corneal abrasions without concomitant ocular injury can be managed and treated with antibiotic ophthalmic ointment, topical cycloplegic agent, and topical ophthalmic NSAID (e.g., ketorolac or diclofenac). Although there is no good evidence that topical ophthalmic antibiotic is indicated in cases where there was no recent history of contact lens wear and the injury with organic material, given the devastating sequela of corneal infection and scarring, use of a topical ophthalmic antibiotic is not unreasonable.2633


History of contact lens wear or injury with organic material raises the risk of infection. These patients should never be patched given the elevated risk of infection, and referred for ophthalmic consultation. Patients with large corneal abrasions may benefit from bandage soft contact lens placed by an eye care professional for comfort. If the affected eye is patched, the patient should follow up next day with an eye care professional to monitor healing and assess for early signs of infection.


Corneal Foreign Bodies

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Oct 26, 2017 | Posted by in CARDIOLOGY | Comments Off on Eye

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