Lieutenant Commander Timothy Hinman, MD, US Navy
Naval Medical Center
As a student of medicine we are always taught "first obtain a thorough history" this is not always possible and may in fact be dangerous if fresh injuries are allowed to go untreated such as the case of an alkali injury. When conditions permit, however, useful history includes a review of current symptoms -time course, evolution. In particular is there loss of vision and how is it manifested. A history of a "curtain being raised or lowered" is seen in retinal detachment. A history of flashing lights may be associated with retinal detachment or migraine headaches. A history of halos associated with vision loss can be associated with corneal edema from glaucoma.
Another common symptom is eye pain. Where is the pain is a key discriminator. Periorbital pain or pain around the eye can be seen in a lid infection or blepharitis, sinusitis or arteritis. Retrobulbar pain or pain behind the eye can be associated with inflammatory processes. Pain at the ocular surface is usual in corneal abrasions or infections (Often this type of pain will improve with topical anesthetics).
Last Past Medical History including a personal history of diabetes or hypertension. Family history of glaucoma or cataracts. Any medications, drug allergies, and previous ocular disease.
A visual acuity should be obtained on almost all patients. Just as in the case
sited beforehand, not always will one be able to be obtained before starting
treatment, usually a gross approximation can be made however. When testing
vision use a Snellen eye or similar chart and have patient stand a distance
of 20 feet. Starting with affected eye have patient cover other eye with
a card or palm and read smallest letters. Record the line read with no errors.
If patient is unable to read anything on chart move him/her to 10 feet and
record as 10/100 etc. Vision should be tested with corrective lenses worn.
If a defect exists visual acuity should be tested through a pinhole. Normally
a pinhole should correct for nearsightedness, farsightedness, and astigmatism.
Pupils can then be examined noting the direct and consensual light responses.
Also note the size, shape, and symmetry of the pupils. Look at the anterior
chamber especially in a setting of trauma note presence of blood or a hyphema.
Is there clouding of the anterior chamber. Is there pus in the anterior chamber
signifying a hypopyon.
Next look at the conjunctiva. Is there injection of vessels, discharge, hemorrhage, or chemosis (edema).
A useful and needed procedure especially when foreign body is suspected is lid eversion to examine the undersurface of the lids. To perform anesthetize the eye with proparacaine or tetracaine. With patient seated, have patient look downward. Examiner should grasp upper lid and eyelashes pulling down and out. Lid can be everted while pushing downward on superior surface of lid with a cotton tipped applicator or CTA. Foreign body or debris can be removed with a moistened CTA.
In testing Extra Ocular Eye Movement have patient move eyes through the six cardinal positions of gaze. That is lateral, medial, medial and inferior, medial and superior, lateral and inferior, and lateral/superior. Each position represents a specific extraocular muscle paired with a specific cranial nerve.
Visual Field testing is also important especially when dealing with visual loss. Face patient at a distance of approximately 1 meter. Have patient cover one eye, and while fixating on examiner's eye, examiners fingers are moved in 4 quadrants of peripheral vision (temporal, nasal, superior, and inferior). Examiner compares patient responses to his own.
Corneal foreign bodies will consist of metal or other debris which has become embedded in the corneal epithelium. Typical symptoms include : pain, tearing, and "foreign body sensation". Sometimes the foreign body sensation is falsely localized to the upper lid. On exam the conjunctiva may be injected. Ideally exam should be performed with topical anesthesia.
To anesthetize topically one of the following products is normally used. tetracaine is usually associated with greater initial stinging has onset within 1 minute with an effect duration of 15-20 minutes. Proparacaine has onset of less than 20 seconds with a duration of 10-15 minutes. Systemic reactions have been documented following use of topical anesthetics and therefore should not be administered if a history of hypersensitivity reaction exists. To help limit systemic absorption of any topically instilled agent, pressure may be exerted in region of the nasal canthus. These agents also impair healing of corneal epithelium and should not be self administered for reasons of delayed healing and potential reinjury.
Treatment involves removing the foreign body. Optimally a slit lamp should be used to aid in visualization. Initial management would include topically anesthetic agent and irrigation with Normal Saline attached to IV catheter allowing the fluid to strike foreign body at an angle. If this method fails a moistened sterile CTA can be used to attempt dislodging. Some practitioners feel CTAs should not be used as corneal abrasions may result and therefore reserve the moistened CTA for use in conjunctival foreign bodies.
Foreign bodies that remain despite previous interventions will require needle removal with a commercial eye spud or sterile needle. If a patient is not cooperative this procedure should not be attempted for obvious reasons. If using a needle first attach a 25 gauge needle to a CTA or 3 ml syringe. Examiner should then place hand with needle to rest on patients cheek. This maneuver will limit unexpected movements. The needle bevel is held tangentially to the eye and the foreign body is scraped. Complications of this procedure include globe perforation, however, this is rare.
After removal consider use of cycloplegics. an antibiotic ointment should
be placed in the affected eye. Patching is usually performed with a 24 hr follow-up
Corneal abrasions are very common to the emergency department. The eye is painful, usually with a "foreign body sensation". The conjunctiva may be injected and visual acuity may or may not be affected. To evaluate first anesthetize the eye and apply fluorescein. To apply fluorescein, ensure contacts are removed as permanent staining of soft contact lens can occur. Moisten the strip with a single drop of sterile Normal Saline and place the strip on the lower lid conjunctiva. A woods lamp or Slit Lamp with cobalt blue filter can be utilized to visualize uptake of the dye at an injured site.
Treatment of Corneal Abrasions involves first ruling out foreign bodies by a careful exam with lid eversion and examination under slit lamp. Once this is done an antibiotic ointment is generally applied such as erythromycin, a cycloplegic can be instilled to prevent ciliary spasm and development of a secondary iritis. The eye is patched for 24 hrs and follow up recommended.
In a setting of trauma a simple corneal abrasion may not be the only complication depending on the mechanism of injury. If penetration of the cornea occurs signs to look for include teardrop shaped pupil, prolapse of the iris, hyphema or blood in the anterior chamber, and lens opacification. The Seidel test may be useful in detection of corneal penetration. To perform use several drops of fluorescein over the ocular surface. If a stream of fluorescein is seen leaking from the globe the test is positive.
Initial treatment goals for penetrating trauma include the philosophy of first doing no harm. Simply rubbing the eye could cause further damage as well as palpation of the globe, and performance of tonometry. To protect then a Fox shield should be placed with tape over the affected eye. Alternatively, a paper cup can also be used to protect against additional applied pressure to the globe. To guard against increasing intra-ocular pressure, the patient should be maintained NPO and consideration given for administration of antiemetics. Tetanus status should be verified and prophylaxis given if indicated. Often antibiotics are given providing broad spectrum coverage, a good choice would be cefazolin and an aminoglycoside. If a large foreign body is present it should be left in place for removal in the operating room. Definitive care and follow-up will need to be arranged with an ophthalmology specialist.
One complication of penetrating trauma is endopthalmitis which is basically an infection involving the deep structures of the eye. The incidence is 5-10% . Visual loss may occur due to this complication.
If unexperienced in management of eyelid lacerations, it is best to refer for repair. Again protect the eye with Fox shield prior to transport and verify tetanus. Partial thickness lacerations, however, can be closed in the Emergency Department provided the patient is cooperative and the physician qualified. Certain injuries must be viewed with caution though as the risk for cosmetic as well as functional result are at stake. In particular if a lac involves medial 1/3 of the lid the canalicular ducts may be severed resulting in persistent tearing. If a full thickness lac involves the lid margin, the tarsal plate may be severed which is a complicated repair. Injuries to the levator tendons in the upper eyelid could result in a traumatic ptosis if not adequately repaired.
Blunt ocular trauma transmits a force to surrounding bony structures. The weakest area is in the orbital floor which is the most common site to be injured in an orbital fracture. Signs of orbital fracture include enophthalmos or a "sinking in" of the affected eye, slight ptosis, diplopia and anesthesia of the ipsilateral cheek which is supplied by the infraorbital nerve. If extraocular muscles are entrapped the patient will display an inability to move eye upward. A waters view X-ray is sometimes helpful showing a fullness in the maxillary sinus antrum and/or an air/fluid level.
Treatment of orbital fractures includes verifying tetanus status. And arranging follow-up for possible surgical repair. Surgery is most commonly performed after 7-10 days. Decision whether to use prophylactic antibiotics can be discussed with the consultant.
Iritis can be classified traumatic or nontraumatic based on the antecedent insult. Basically bruising and inflammation of the iris and ciliary body lead to typical symptoms of dull ocular pain, photophobia, and blurring of vision. Examination of the eye will reveal decreased visual acuity, miosis of the affected eye and ciliary flush or a reddening of sclera at the limbus. Slit lamp exam typically shows "cells and flare" in the anterior chamber and if intraocular tension is measured it will often be low.
Treatment of Iritis involves cycloplegics such as homatropine or cyclopentalate. Steroids are usually given, however, only give under consultation with an ophthalmologist and ensure patient is referred for follow up.
Central retinal artery occlusion is one of several diagnoses that one needs to consider when a patient presents with acute loss of vision. This process is secondary to embolic phenomenon which is secondary to atherosclerotic disease. The result is sudden, monocular, painless vision loss. On examination the patient may display complete blindness to decreased ability to finger count or perceive light. Grossly the eye appears normal, however, on ophthalmoscopy a pale retina is seen, bloodless arterioles, and "box- car" segmentation of the retinal veins. A "cherry red spot" can also be seen at the fovea. Outcome for this disease is poor if treatment is delayed more than two hours. Immediate referral to an ophthalmologist is needed for anterior chamber decompression or lateral canthotomy. Until this occurs digital globe massage is advised to reduce intra-ocular pressure.
Central retinal venous occlusion is thought to result from compression of a retinal vein which lies adjacent to a retinal artery atheroma. Compression leads to stasis typically over a period of hours. Resulting loss of vision is painless. Examination will reveal normal or decreased visual acuity with variable central and peripheral field defects. Fundoscopy will show venous engorgement.
Optic neuritis may be secondary to infection, inflammation, or demyelinating diseases of the optic nerve. Patients typically will complain of central vision loss and periorbital pain made worse with eye movement. The time course is hours to weeks. Examination will show varying degrees of central vision loss otherwise essentially normal.
Hysterical blindness is not uncommon to the emergency department. The examination except for subjective loss of vision will be normal. To aid in making diagnosis use of an optokinetic device, which is a geometrically patterned tape or drum, will produce optokinetic nystagmus when rotated or passed before patients eyes.
A final type of painless monocular vision loss is retinal detachment. The patient
typically relates a history of flashing lights and floaters along with a
gradual raising or lowering of a curtain. On examination occasionally one
will see an undulating retina on fundoscopy but this is not the rule. When
this diagnosis is being considered, ophthalmology consultation is needed.