Written by Dr. Khalil Al-Salem
Eye trauma can be divided into blunt injury , penetrating injury and chemical injury.
Blunt injuries: those injuries inflected by a blunt object; an object that doesn’t have sharp edges.
Penetrating injuries : involves sharp objects or high speed bullets, which settles inside the globe.
Perforating injuries : those that has an entrance and an exit point.
Students are expected to master the understanding of Corneal abrasion, corneal laceration, orbital wall fractures, lid laceration, chemical injuries and rupture globe.
The surface of the cornea is covered by a thin layer of epithelium. This “rug” of clear skin is only loosely adherent and is easily scraped off. These surface abrasions are common and we see them daily. The cornea contains more nerve innervation (per surface area) than any other place in the body so these abrasions “hurt like the dickens,” with patients complaining of excruciating pain and intense photophobia. Abrasions are easy to see, even without a microscope, as the raw surface will uptake fleurosceine and glow bright green under a blue light.
Fortunately, abrasions recover quickly and will often completely heal within 24 hours. Until complete epithelial healing you treat with aggressive lubrication and follow these eyes closely to insure the raw wound doesn’t become infected. Many physicians will treat an abrasion with empiric erythromycin ointment as well, reserving more aggressive antibiotics like ciprofloxacin for contact lens wearers and “dirty wounds” caused by tree branches, etc..
If an abrasion does become infected, you’ll see a white infiltrate at the wound. Any abrasion with an infectious infiltrate is officially called a “corneal ulcer.” Depending upon the size and location of an ulcer, you may need to culture the wound and tailor your antibiotic coverage accordingly.
Most corneal scratches only involve the surface epithelial layer. If the injury goes deeper into the stroma, then you have a laceration. With any laceration you want to insure that the cornea hasn’t perforated. You can check corneal integrity with the “Seidel test.” You wipe a strip of fluorescein paper over the wound and see if dye flows down the corneal surface, indicating leaking aqueous fluid.
If a patient is “Seidel positive” than you have an open-globe injury – time to call in your seniors for possible surgical repair!
Orbital Wall Fractures:
The bony orbital walls are thin and tend to break with blunt impact to the eye. This is especially true of the orbital floor and medial wall. These orbital fractures are common and you will see them weekly. mostly these are caused by a fist trauma or a road traffic accidents.
The face is designed like a modern crash-tested car, with many areas designed to crumple and diffuse energy upon violent impact. The sinuses are air-filled crumple zones that protect the brain and other vital structures. When the eye is hit, orbital contents (usually fat) break through and herniate into one of these sinuses. As bad as this sounds, this setup keeps the eye from exploding from high impact pressures.
Most of the time these orbital bones heal fine with no long-term problems, with patients merely having a great deal of orbital and periorbital swelling that resolves over a few weeks. However, sometimes the broken bone creates a “hinge” or “trapdoor” that entraps fat or extraocular muscles. If there is significant entrapment or enophthalmos, we need to repair the break. During surgery we can release the muscle and bolster the floor to keep orbital contents from herniating back through the defect. This surgery is usually performed by an oculoplastic specialist.
What are the indications of orbital fracture repair ?
1- Oculo-cardiac reflex, every time the patient looks up he starts to have sudden bradycardia and dizziness. This is a life threatening complication caused by muscle entrapment (usually inferior rectus) in the inferior wall of the orbit.
2- Cosmetic; significant enophthalmos causing facial difference, and disfigurement, which is the most common indication.
3- Diplopia in primary or inferior gaze, this can be checked by Extra-ocular motility examination.
When evaluating orbital fractures, focus on the following exam findings:
1. Optic nerve functions; Visual acuity, color vision, visual field and RAPD.
2. Extraocular : movements: Usually decreased from swelling or muscle contusion, but make sure there isn’t any gross muscle entrapment.
3. Proptosis : Measure the degree of proptosis or enophthalmos using the Hertel exophthalmometer or a regular ruler.
4. Palpate : Feel along the orbital rim for step-off fractures and subcutaneous emphysema (air crepitus).
5. Sensation : Check sensation of the V1 and V2 sensation on the forehead and cheek. V2 runs along the orbital floor and can be damaged with floor fractures.
Most of these patients do fine and we see them a week later with marked improvement in swelling and motility. In the meantime, you treat empirically with Keflex or Augmentin, advise Afrin nasal spray, and recommend “no nose blowing” (you don’t want to blow air from the sinuses into the orbit).
When evaluating lid lacerations, you need to determine if the laceration involves the lid margin and how close the cut is to the canalicular (tear drainage) system. Most of these lid lacerations are straight-forward to repair, though special effort is made to align the lid margins to avoid lid notching and misdirected eyelashes.
If the laceration is medial (near the nose) you need to worry about the canalicular tear system – repair of this drain is much more involved and involves threading silicone tubes down into the nose to keep the canaliculus patent.
Metal showering on the eye:
Small pieces of metal can fly into the eye – an unfortunate event occurring primarily in welders or construction workers. Particles of metal stick onto the cornea causing small abrasions and discomfort. Metal rusts quickly and will form a rust ring within a day. You can remove metal objects and rust rings at the slit-lamp using a needle. You can also use a small drill to drill off the rust-ring. If the rust is deep, or aggressive pursuit seems to be making the situation worse, you can leave the residual rust in place as most of it will eventually migrate to the surface by itself.
Anytime you have metal-striking-metal injuries, you must entertain the possibility of an intraocular foreign body. Small metal fragments can enter the eye at high speed and leave little or no signs of injury. Metal is very toxic to the retina and can kill the retinal cells if not detected. If you have any suspicion for penetrating injury, you should always order a thin-slice CT scan of the head to look for metal pieces not obvious on exam. You want to avoid MRI in this setting to avoid creating a moving projectile inside the eye.
Household cleaners contain abrasive solvents like bleach and ammonia that are extremely dangerous when splashed into the eye. The first thing you do with any chemical injury is:
Irrigate, Irrigate, Irrigate, Irrigate, Irrigate, Irrigate, Irrigate!
The final visual outcome for a chemical burn is going to depend upon how quickly the chemical is washed out of the eye. If a patient calls you with a chemical conjunctivitis, tell them to immediately wash their eyes out! If the ER calls you with a chemical conjunctivitis, tell them to start irrigating immediately – several liters in each eye. Then grab your equipment and pH paper and head on down there!
Acids are less dangerous than bases as acids tend to precipitate denatured proteins and this limits tissue damage. Bases, on the other hand, just keep on going, so you need to continually irrigate , on average 20 min minimum.
On exam you want to carefully check the state of the cornea – hopefully, it is still clear. A red, inflamed conjunctiva is actually a good finding: if the conjunctiva is white, that means its blanched out from extreme damage. Be sure to flip the lids and irrigate/sweep the fornices to remove any material that may be retaining chemicals. look for small blue structure these are reservoir for the offending material, as it will continually spill on the cornea.
Chemical injuries can lead to significant scarring that may require corneal transplant if bad enough, so you want to be very aggressive with that irrigation
Keep in Mind Khalil tip
Irrigate, irrigate, irrigate.
Steroids eye drops, antibiotic eye drops lubricant and Vitamin C for anti collagen degradation.
A hyphema describes blood floating in the anterior chamber, a common finding after blunt eye trauma. If the bleed is large, the blood will settle out in a layer at the bottom of the anterior chamber. If the entire AC is filled with blood, you’ll see an “8-ball hyphema.” Most of the time, however, the bleeding is microscopic and can only be seen as “red cells” floating in the aqueous fluid.
Blood typically clears well, though you can get staining of the cornea if the blood is persistant or coexists with high eye-pressure. Encourage your patient to sleep with their head elevated (to help the blood settle) and to avoid straining. You typically give steroids (to decrease the inflammatory response) and a cycloplegic dilating drop to help with photophobia. As with iritis, this dilation also keeps the iris from sticking to the underlying lens and forming synechia. In Jordan, consider checking for sickle cell disease, as it is prevalent in the middle east. If they do have sickle cell, avoid carbonic anhydrase inhibitors as they cause a local acidosis that worsens sickling.
Follow these patients daily, as the bleeding can get worse. The main danger time is days 3 to 5 because this is when clots can contract and rebleed. You need to monitor their pressure as blood can clog the trabecular meshwork. After the blood has completely resolved and the eye is quiet, perform a thorough gonioscopy exam to access for “angle recession.” This is when the ciliary body splits from the blunt trauma — this is a sign (but not a causative factor) that the patient has also likely suffered trabecular meshwork damage and may eventually develop glaucoma in that eye sometime in the future.
Open Globe Injuries:
The eye can be perforated many ways … I’ve seen firecracker explosions, gunshot wounds, car wrecks, and domestic accidents that have perforated the eye. Visual outcome is usually terrible and a blind, painful eye may need later enucleation.
If you suspect an open globe injury you need to evaluate the eye in the operating room. One thing to remember – if you suspect an open globe injury, cover the eye with a shield and don’t push on it. You could extrude the eye contents (pop it like a grape) if you push on the eye.