Eye Injuries and Illnesses in Remote Environments
1st July 2019
Eye injuries in present serious and complicated issues in any setting but especially in a remote or austere environment where one of the most important decisions is when to stay and when to evacuate.
The initial step to approaching a patient with an ocular malady is to classify the cause as traumatic or non-traumatic
Inspect the affected eye, briefly but thoroughly, with a bright white light source, and compare it with the opposite eye:
The sclera should be intact.
The anterior chamber should be free of pus or blood.
The iris should be normal in size and shape.
The pupil should be normal in size, shape, and reactivity, and it should be symmetric with the other pupil unless there is a history of asymmetry (anisocoria).
If any of these conditions are not met, the patient should be evacuated for professional assessment and treatment.
Eversion (turning inside out) of the upper lid is usually necessary to examine the entire conjunctiva. After grasping the lower lid and applying traction, examine the conjunctiva beneath it as well. Inspect the entire clear bulbar and pink palpebral conjunctiva for trauma, foreign body, or other sources of symptoms, such as a hordeolum (stye) or an ingrown or inverted eyelash.
Examine carefully the groove about 2 mm from the lash margin of the everted lid. Tiny objects frequently lodge here and may not be immediately visible. Use the ophthalmoscope for magnification if necessary or a camera phone with high magnification. Older patients often have ingrown hairs (trichiasis) that can cause a foreign body sensation. Trichiasis most frequently involves the lower lid, and if there are only a few hairs, they can be plucked out with fine forceps.
Because patients with a corneal abrasion are usually hypersensitive to light, let them know when you are going to need a bright white light for only a short while, and that the room will otherwise be darkened. The remainder of the examination is done with a blue light, which should be more comfortable.
Contact lenses should be removed before the eye is stained (fluorescein can stain them permanently)
The patient should be warned that objects in his or her vision may temporarily appear yellow.
Instil fluorescein dye by moistening a sterile fluorescein strip with one or two drops of sterile saline or, asking the patient to look up, and gently touching the lower conjunctival sac for 3 to 5 seconds.
Use a minimal amount of solution when wetting the strip. This usually helps visualize the defect by staining only the defect as opposed to staining the entire eye.
Try not to touch the cornea directly with the strip because this may cause iatrogenic staining. After instilling the fluorescein, have the patient blink a few times to remove excess tears, and blot them with the tissue. This is helpful to distinguish true staining from fluorescein saturation of the tear film.
Inspect the cornea with magnification under a cobalt-blue light source. If the entire cornea is stained, irrigate the eye again and re-examine. Abraded areas of the cornea should remain highlighted with fluorescein.
Traumatic eye injuries
Current evidence based guidance (1, 2) suggests that the standard practice of bandaging both eyes (with the intention of reducing binocular movement of both eyes) serves no purpose (3-5) and may in fact cause complications, certainly if pressure is applied.
The practice of banding both eyes in not part of current UK JRCALC or NICE guidelines.
In many cases the practice of applying a rigid, ventilated, shield will suffice with in the increased benefit reducing stress and anxiety of the casualty and also facilitating evacuation.
Superficial lid laceration
A superficial lid laceration does not penetrate the full thickness of the eyelid and does not include the lid margins or the eye itself.
Treatment of superficial lid lacerations is the same as that for other minor lacerations.
Use clean gauze to apply pressure to the cut to stop the bleeding. It is important not to put pressure on the eye but rather on the surrounding bones of the orbit.
After the bleeding stops, strongly irrigate the wound with clean water or saline solution to remove dirt or foreign objects.
Attempt to close the laceration with tape strips.
Apply topical antibiotic ointment in a thin ribbon to the wound. Cover the wound with a sterile non-adherent dressing or gauze and tape the dressing in place.
Monitor daily for signs of infection, such as redness, swelling, pain, and pus. Depending on the severity of the laceration, evacuation may be necessary for definitive repair.
Complex lid laceration
A complex lid laceration penetrates the full thickness of the lid and/or includes the lid margins.
Penetration of the globe must be ruled out.
Use sterile gauze to stop the bleeding. Irrigate the cut with saline solution or clean water if saline is not avail- able. Saline is preferable, since irrigating a complex lid laceration will most likely include irrigating the eye.
Most health care providers are not comfortable closing complex lid lacerations. There is a considerable risk of poor outcome if the laceration is not closed appropriately. In cases where the treating health care provider is not qualified or confident about closing the wound, the wound should be treated with antibiotic ointment and then kept covered.
Due to the need for repair, patients with complex lid lacerations should be evacuated if possible.
Blunt force to the globe or surrounding bony orbit and soft tissues can fracture the thin bones that hold the eye in place.
In most cases, significant periocular bruising (black eye) and swelling will occur.
There may also be restriction of eye movements, which is called entrapment.
Significant swelling, restricted eye movements, clear fluid leaking from of the nose, and decreased vision following blunt trauma to the orbit suggest considerable damage. The casualty should be evacuated for evaluation and treatment.
Penetrating foreign body
If a foreign object has penetrated the eye, do not try to remove it. Stabilize the object by taping a sterile dressing in a donut shape around the eye and then taping a cup or pair of glasses over the eye to prevent any jarring of the embedded object.
You may consider patching the other eye shut to prevent eye movement if the victim does not have to use his or her sight to navigate out of the wilderness however in most cases this is unpractical.
If the eye has been punctured, resulting in an open globe, and no foreign object is present, a protective shield should be taped over the eye. Sunglasses can function as a shield by being taped over both eyes.
In any possible case of globe penetration, it is important not to put any pressure on the damaged eye. External pressure may raise intraocular pressure, resulting in expulsion of intraocular structures. An open globe injury is a true emergency and should result in immediate evacuation to prevent infection and vision loss.
Abrasions occur when the epithelial layer of the cornea is disrupted
A corneal abrasion may result in moderate to severe pain, tearing, and sensitivity to light
Casualties often report having a foreign body sensation in their eye
Evaluate the eye to ensure there is not a globe perforation or foreign body on the cornea
If available apply a topical anaesthetic. This will classically resolve all discomfort and also allows for further evaluation of the eye
Apply fluorescein dye and examine the eye with a blue or UV light. If present, a corneal abrasion will appear bright green when viewed with the UV light (see picture below).
There is no evidence to support the application of an eye shield or patch for a corneal abrasion (86-88).
Common practice is to apply a topical ophthalmic antibiotic if available, particularly in contact lens wearers or abrasions from vegetative matter. If not available, the abrasion should still heal well.
Artiﬁcial tears can provide substantial relief with minimal to no side effects
Eye patching is not a necessity and does not decrease time to recovery, but some victims report that this provides relief from their symptoms.
If the casualty wears contact lenses, then he or she should not wear them until the abrasion is fully healed. They are at risk for developing a corneal ulcer.
The epithelial layer of the cornea heals rapidly, usually within 24 to 72 hours
Hyphema (blood in front of the lens)
A hyphema is a collection of blood in the anterior chamber of the eye and can result from blunt or penetrating trauma.
Hyphemas are best examined in the sitting or standing position, as the blood will settle, resulting in the formation of a meniscus in the anterior chamber. This allows the provider to determine how much blood is present. Small hyphemas can be difﬁcult to appreciate when the casualty is lying ﬂat.
Hyphema is a serious condition that mandates evacuation due to its potential complications, which include acute glaucoma, vision loss, and rebleeding.
Frequent re-evaluation recommended given potential for rebleeding resulting in glaucoma and worsening status.
Use an eye shield to protect the eye from any further trauma.
Avoid aspirin, ibuprofen, or any other medications that may cause more bleeding.
Control of nausea/vomiting is important as nausea/vomiting may result in increased intraocular pressure.
Activity should also be restricted as much as possible during evacuation, though ambulation has not been shown to increase the risk of rebleeding.
If able, elevation of head to 30 degrees promotes settling of the blood in the anterior chamber away from the visual axis while maintaining arterial blood ﬂow compared to head fully upright.
Non-penetrating foreign body
Non-penetrating foreign bodies can result in pain and irritation. If natural tearing does not clear the eye of the foreign body, irrigating the eye with saline solution is sometimes successful. Larger chunks can be removed from the conjunctiva with a cotton swab.
Do not attempt to remove foreign objects embedded in the eye. If an object persists or cannot be removed from the conjunctiva, apply a strip of antibiotic ointment to the lower lid.
If necessary for pain control, patch the eye as for a corneal abrasion. If there is any suggestion of an infection, do not patch the eye.
It is possible for a casualty to lose vision in an eye that looks completely normal. There are various causes of acute vision loss. Each is serious and can result in permanent vision loss. Whenever visual acuity dramatically decreases, or there is a sudden loss of vision, evacuate the victim immediately.
Retinal detachment occurs when the retina (the innermost, posterior layer of the eye) detaches from the middle layer). This may be because of trauma or may occur spontaneously. It is more common in people with severe near sightedness because of the shape of their eyes.
Initial symptoms commonly include a sensation of flashing lights followed by a shower of “floaters.” Over time, this may lead to a shadow in any part of the visual field. Left untreated, this can spread to involve the entire visual field within a short period of time. Surgical intervention can help to preserve vision, so prompt evacuation must ensue shortly after initial symptoms are noted.
Red Eye comprises a group of eye conditions which could be benign or serious. Some will require immediate evacuation and other will simply require pain relief and TLC.
Subconjunctival haemorrhage is accumulation of blood in the space between the conjunctiva and sclera. This results in an extremely red-looking “bloodshot” eye but is rarely a serious condition.
This condition may occur spontaneously or as a result of increased intrathoracic pressure, such as that which occurs with straining or coughing. It normally resolves over a period of a few days to two weeks without treatment.
If this occurs from trauma, examine the eye for other more serious conditions, such as a foreign body or puncture.
Conjunctivitis (Infection on the surface of the eye)
The major causes of conjunctivitis are viral, bacterial, and allergic although acute bacterial conjunctivitis is much less common than is viral conjunctivitis.
Viral and allergic conjunctivitis usually require no treatment. In the wilderness, the most practical treatment for the symptoms of these conditions is cold compresses if ice or a cool wet cloth is available.
Bacterial conjunctivitis is most often treated with a broad-spectrum ophthalmic ointment or suspension.
Since the cause of conjunctivitis may be difficult to diagnose, if inflammation becomes worse after a few days, it may be appropriate to evacuate for evaluation and treatment.
If a red eye is accompanied by decreased visual acuity or if the cornea becomes opaque or cloudy, evacuation is necessary because these latter symptoms possibly denote more serious ocular disease.
This represents an acute corneal defect caused by an infection and are commonly seen in contact lens wearers.
Topical anaesthesia will relieve most of the pain of the ulcer, though a small amount may remain due to the pain caused by ciliary muscle spasm
Fluorescein uptake will be noted on exam
Contact lenses should not be worn if an ulcer is noted
Treatment is topical ﬂuoroquinolones and evacuation.
Herpes Simplex Virus (HSV) Keratitis
This is a corneal infection that results from HSV inoculation and results in severe eye pain, similar to an ulcer or abrasion. On fluorescein staining a dendritic (fern like in appearance) lesion will classically be noted.
There may be a history of prior herpetic infection
The casualty should be evacuated for treatment. If you have oral or topical antivirals, you can start them while coordinating evacuation.
UV Keratitis (Snowblindness)
The protective layer of the cornea is easily damaged by exposure to ultraviolet radiation from direct sunlight, reflection off snow, or reflection off water. Symptoms are mild to severe eye pain, reddened eyes, sensitivity to light, tearing, blurry vision, and foreign body sensation in the eye 6 to 10 hours after exposure. These symptoms commonly involve both eyes, which is a clue to this diagnosis.
Prevention is the key with this exposure. When travelling on snow or water, it is important to wear sunglasses or glacier goggles in order to prevent corneal damage.
Altitude is a signiﬁcant risk factor as UV damage is more signiﬁcant at altitude.
This injury is easily prevented with sunglasses with side shields. Always wear proper eye protection in bright light, especially when light is reflected off snow or water.
Sunglasses or eye patching may help with the discomfort
Glaucoma comprises a range of conditions involving increased intraorbital pressure often found in individuals typically over age 50. In many cases this can present as a painful but relatively benign condition.
Acute Angle (or Closed Angle) glaucoma is a serious condition which can result in permanent loss of vision.
In a healthy eye, fluid balance between production and drainage is maintained by fluid drainage through the trabecular meshwork between the cornea and iris. The terms acute or closed angle refer to a narrowing of these drainage channels, cause a reduction of drainage and increased pressure within the eye.
Diagnosis is made in the clinical setting by measuring intraocular pressure, but in the wilderness you should be suspicious for angle closure glaucoma if the patient’s pain is deep, not relived by topical anaesthesia and is associated with a pupil that is ﬁxed in mid-dilation and a steamy (cloudy) cornea.
Nausea and vomiting are often present
The casualty may experience more pain in low light or with their eyes closed – pupil dilation can increase pressure further.
Treatment is with topical pilocarpine if available
Acetazolamide, if carried, can also be given.
Evacuate urgently, as prolonged elevated ocular pressure does result in loss of vision
Evacuate immediately if the globe has been perforated.
Evacuate immediately if there is a sudden loss of vision in a normal-appearing eye.
Evacuate as soon as possible if there is a complex lid laceration or hyphema, or if the cornea becomes cloudy.
Evacuate as soon as possible any acute red eye condition where the pain is severe and not relieved with topical anaesthesia
Evacuate corneal ulcers as soon as possible
Few red eye conditions that do not have pain or improve with topical anaesthesia should be evacuated. Corneal ulcer, HSV keratitis, or retained conjunctival foreign body are of the few that should be evacuated
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