This section does not attempt to duplicate the material in the references listed at the end of this section. Rather, it outlines special considerations in the management of several ocular emergencies by the operational medical officer. Understandably, all recommended treatments may not be possible in some locations. Frequently this occurs in a remote area where immediate consultation or MEDEVAC is an impossibility. Purchase and use of one or both of the listed texts is strongly recommended. The first reference is a particularly good practical guide. Both should be consulted for detailed information on evaluation techniques and specific treatment regimes.

History
The ocular history should include date and time of onset of symptoms, any precipitating events, any past eye surgeries or disease, use of corrective lenses, and any associated symptoms.

Visual acuity
If a Snellen chart is not available, use a pocket-sized near vision card, or any other printed material (i.e., newspaper). The patient should wear their glasses for this exam. If the patient wears corrective lenses and they are unavailable have them look with one eye at a time through a pinhole (made by sticking a pin or needle through a 3 x 5 card). The pinhole effect serves to eliminate most of the optical aberrations of a patient’s refractive error, thereby giving the examiner a reasonable estimate of the patient’s visual potential even if their glasses or contact lenses are not available.

Pupil exam
To rule out afferent pupillary defect, perform the swinging flashlight test by moving the light back and forth from one eye to the other, pausing at each eye for a couple of seconds (use the count of one, one thousand etc.) to observe the pupil. In the normal exam, the illuminated pupil should constrict and then show some slight enlargement. Any asymmetry between the eyes in constriction or escape constitutes a relative afferent pupillary defect.

Ocular motility
Up, down, left, right, and 45 degrees between each direction (gaze up and out, gaze up and in, etc.)

Assess visual fields by confrontation
Sit facing the patient, with the patient and yourself covering opposite eyes (patient’s left eye, examiner’s right eye). You should hold up fingers from each hand and have the patient count the total. Repeat in different meridians.

• If a penlight is available, check for conjunctival injection or blanching, corneal opacities, and anterior chamber depth.

• If a slit lamp is available, examine the lids, lashes, conjunctiva, cornea, anterior chamber, iris, and lens.

Fundus exam
If this exam is difficult, dilate the pupil with Tropicamide 1%, 1 gtt. Neosynephrine 2.5%, 1 gtt can be used in addition to Tropicamide to facilitate pupil dilation.

If a corneal laceration or a post-surgical wound leak is suspected, perform a Seidel test by touching a fluorescein strip, moistened with topical anesthetic, directly to the area of suspected perforation.

• When viewed with a white light, a leak of aqueous will appear as a greenish-yellow stream flanked by dark orange or blackish nonfluorescing dye.

• When viewed with a Woods Lamp or the blue beam of a slit lamp, a leak will appear dark, with greenish-yellow staining on either side.

Etiology

• Blunt trauma with rupture.

• Missile injury with or without retained intraocular foreign body.

Signs and symptoms.

In some cases, the rupture site may not be readily apparent. A high index of suspicion must be maintained in evaluation of ocular trauma.

• Conjunctival edema, chemosis, or hemorrhage.

• Hyphema.

• Limitation of extraocular motility.

• Obvious rupture of cornea or sclera.

• Uveal tissue (iris, ciliary body) exposed or prolapsed.

Management

• Avoid direct pressure to the globe at all times.

• Tetanus toxoid (0.5 cc IM) if not up to date.

• Parenteral broad spectrum antibiotics (Cefazolin 1 g IV q8h and Gentamicin 1.5 mg/kg loading then 1 mg/kg q8h). Do not use any topical medicines in a potentially ruptured globe.

• Protect traumatized eye with a Fox shield. If no aluminum shields are available, the bottom half of a Styrofoam cup can be taped in place over the eye.

• Urgent MEDEVAC - surgical repair should be accomplished as soon as possible, and not later than 24 hours from the time of trauma.

• Consider mild analgesics and antiemetics as needed to avoid Valsalva maneuvers.

• Keep patient NPO (nothing by mouth), if possible.

• Bed rest, use a mild sedative if necessary.

• If an intraocular foreign body is suspected, the patient will eventually need x-rays and an orbital computed tomography (CT) with coronal sections. Magnetic Resonance Imaging (MRI) should be avoided due to the high probability that the foreign body may have magnetic properties.

Chemical Burns

Etiology: chemical exposure of eye

Signs and symptoms

• Corneal epithelial defects or opacification

• Injection or blanching.

• Chemosis (conjunctival edema)

• Any of the above signs may be associated with pain, tearing, and photophobia

Management

• Do not waste time taking a detailed history or performing an eye exam. Begin immediate, copious irrigation with at least 2 liters of eyewash, normal saline, water, (whichever is fastest), for a period of more than 30 minutes. Use a paperclip to roll out (evert) the upper and lower lid so as to irrigate any chemical or particulate matter that may be trapped in the fornices. A dampened Q-tip (cotton-tipped applicator) can be used to remove small foreign bodies and/or particulate matter.

• Five minutes after stopping irrigation check the pH of the inferior cul-de-sac. Continue irrigation until the pH is neutralized at 7.0. (pH papers = NSN 6640-00-442-9005, but a urine dip stick will work).

• Topical anesthesia or lid retractors may be necessary (paper clips can be opened into an elongated S shape, with will suffice for lid retractors).

• A commercially available irrigation kit (Eye Irrigatorä , FSN 6515-01-458-2634) is available to facilitate irrigation of the eye and clear the fornices. It is important to fully irrigate the fornicies because these can trap and harbor residual chemicals.

• After the pH is neutral, cycloplege with Scopolamine 0.25% 1 gtt, antibiotic ointment, pressure patch for 24 hours, and oral pain medications as needed.

Types of chemical injury

• Acid - damage immediate and nonprogressive.

• Alkali - progressive tissue destruction will result in loss of vision and loss of the eye if not promptly and adequately irrigated.

Management

• Topical antibiotics (Sulfacetamide, Erythromycin or Ciprofloxacin, 1 gtt TID.).

• Cycloplegia (Cyclogyl 1% QID, Scopolamine 0.25% TID).

• Oral analgesics.

• Urgently MEDEVAC the patient if blanching and/or corneal opacification is present.

Central Retinal Artery Occlusion (CRAO)

Etiology

• Arteritic (temporal arteritis).

• Nonarteritic (embolic, atherosclerotic).

Signs and symptoms

• Acute, profound, painless loss of both central and peripheral vision in the affected eye.

• Marked visual field defect (test by confrontation).

• Afferent pupillary defect (test by swinging flashlight).

• Fundus: arteriolar attenuation, cherry red spot, optic nerve pallor.

• Note: total retinal destruction begins within 90 minutes of total occlusion - many patients don't present until several hours after onset; prognosis is extremely poor.

Treatment (usually not effective but should be attempted).

• Keep the patient lying flat.

• Massage globe: 15 seconds of firm digital pressure, followed by 5 seconds of sudden release, repeat over a 10 to 15 minute time frame.

• Acetazolamide 250 mg x 2 by mouth, as a one time dose.

• Have the patient breathe into a paper bag; increased CO2 acts as a vasodilator and may increase perfusion.

• If temporal arteritis is a possibility (i.e., patient older than 55 along with other symptoms consistent with the diagnosis), begin high dose pulse steroids (1 gm Solumedrol IV q12 hours followed by 100 mg Prednisone by mouth daily). Obtain an erythrocyte sedimentation rate (ESR).

• MEDEVAC is appropriate (but not emergent).