Okay, guys. We had a difficult question here.
The likely type of question you'll see on the real USMLE.
Let's put on our thinking caps and dive right in.
A 28-year-old man presents to the emergency department after a window he was going to install at his home fell on him.
The patient complains of left ocular pain, blurred vision, and obscured lower portion of his eye visual field.
The patient's vital signs are as follows: the blood pressure is 140/80, the heart rate is 88,
the respiratory rate is 14, and the temperature is 36.9°C.
Examination shows multiple superficial lacerations on his face, arms, and legs.
Examination of his right eye only shows a superficial upper eyelid laceration.
Examination of the left eye shows conjunctival hyperemia, a peaked pupil, hyphema, and a vitreous hemorrhage.
The fundus is hard to visualize due to the vitreous hemorrhage.
Which of the following is the best next step to undertake in the diagnosis and management of this patient?
Answer Choice A: Ultrasound examination of the left eye.
Answer Choice B: Examination of the left eye with fluorescein.
Answer Choice C: Examination of the fundus with a tropicamide application.
Answer Choice D: Placing an ocular pad onto the affected eye,
or Answer Choice E: Systemic administration of vancomycin and levofloxacin.
Now take a moment to come to the answer by yourself before we go through it together.
Okay. Like I said guys, this is a hard question.
It's important and it's the type of question you will see on the exam.
Now, let's go through the question characteristics.
This is a surgery question and really it's ophthalmological surgery.
Someone's coming in, they have trauma to the eye, the eye sounds horribly damaged, and the question stem -
likely we're going to be calling surgery to come in and help.
Now, this is a 2-step question.
First, we have to figure out what's going on and then what is the next best step in management.
And of course, the stem is required because there's lots of details that we need to filter through to come to our conclusion.
Now to walkthrough the question.
So, we have a 28-year-old male presenting and he's coming after trauma in which a window fell on him.
The chief complaint is pain and limited function of the left eye.
He has blurred vision, when we asked about his limited functions,
and he has obscured lower portion of his visual field, and the right eye is fine.
The clinical exam is significant.
He has multiple superficial lacerations, probably from the broken window glass cutting him,
but his left eye has a lot of scary findings. Conjunctival hyperemia, a peaked pupil, hyphema,
which is a pooling of blood between the iris and cornea, he has a vitreous hemorrhage, and you can't see the fundus.
So the diagnosis here is an open-globe injury wound.
Now, after we know it's an open-globe injury wound from the glass cutting his eye,
we need to determine what's the next best step in management.
When you have an open-globe injury wound, it's really a situation of fragility.
The treatment here is not to cause any further damage, that is:
don't increase pressure through any mechanical application or increase fluid in the eye.
And of course, you want to prevent infection which is endophthalmitis.
And you want to treat it.
It's important not to apply any pressure to the wound.
So looking at our answer choices, we can eliminate ultrasound, the fluorescein,
the tropicamide, or placing an ocular pad.
Open-globe injuries, you don't want to touch.
Thus, the last answer remaining is Answer Choice E which is giving systemic administration of vancomycin and levofloxacin.
Now note they did not say local into the eye.
Again, we don't want to mess with the eye.
We don't want to increase pressure. It's systemic administration.
So, antibiotic treatment is the best choice here to prevent infection.
So the answer here is Answer Choice E, the systemic administration of vancomycin and levofloxacin.
Let's go through these answer choices in a bit more detail and talk a bit more about open-ocular wounds.
So this patient's presenting with an open-ocular wound.
And like we said, among the listed options, systemic administration of vancomycin and levofloxacin
or the any antibiotics that give you staff coverage is a proper next step in the management of these patients.
Open-ocular wounds refer to mechanical eye trauma in which the outer fibrous layer of the eye,
the sclera or the cornea, is damaged for its full thickness.
The laceration is a trauma that's caused by a sharp object and the rupture can occur at this blunt trauma.
Eye penetration is a term that's used in an injury in which there is only entry into the wound.
And eye perforation is a term that's used when you have injury with both entry and exit wounds.
For open-ocular wounds, men are 5.5 times more likely to get open-ocular wounds than women.
And a large portion of these open-ocular wounds constitute occupational and home trauma associated
with negligence of safety measures such as wearing safety goggles.
Open-ocular wounds maybe obvious if there is a gross deformity of the eye resulting from a fluid volume loss
or prolapse of the uvea through the wound.
Other signs that can be varied that's not that obvious, which we saw on this patient,
are going to be a peaked or eccentric pupil. You can also have a deformed or asymmetric iris,
you can have a hyphema, you can have some conjunctival hemorrhage,
or you can have decreased vision, or even a relative -- a factory pupil defect, also called a Marcus Gunn pupil.
Now, what happens here in a relative afferent pupillary defect is you have a lesser pupillary constriction perceived
which is actually dilation when a bright light is applied briskly from the unaffected eye to the affected eye.
Now, if an open-ocular wound is apparent or a suspected,
it is critical to avoid an increase in intraocular pressure as it can increase the extend of the trauma.
Using ocular pads, tonometry, manual compression, or any medications
that can increase intraocular pressure are should be avoided.
And that would even include ketamine and cycloplegics.
Surgery is the single definitive method of treatment for this condition
and it should be performed ideally within the first 24 hours to avoid complications.
The possible complications include: loss of vision, loss of the eye, infection
which is endophthalmitis, and sympathetic ophthalmia.
Now, let's go through the other answer choices to see why they're wrong.
Answer Choice A, ultrasound examination is, you know, an efficient way of detecting the extent of injury
but it assumes application of pressure with the ultrasound probe onto the injured eye
and we want to, of course, avoid pressure.
If we had to get imaging, we would want to a CT scan.
Answer Choice B, which is using fluorescein to examine the left eye -
now the presence like we said of an open wound is very likely considered the mechanism trauma.
The presence of iridial and pupillary deformity is also seen.
But in this case, we don't want to apply any solutions to the eye
because we don't want to affect intraocular pressure.
Answer Choice C, examination of the fundus with a tropicamide application -
so tropicamide is a mydriatic and a cycloplegic agent which causes an increase in intraocular pressure.
And again, we want to avoid this in this condition.
And answer choice D is a placing an ocular pad which again would increase ocular pressure which we want to avoid.
Now, let's review some high-yield facts for different types of eye injuries.
Looking at our diagram or our algorithm here, we start with eye injury.
You can have an open-globe injury which is what this patient had,
which is a full-thickness wound of the eyewall. You can have a rupture or a laceration.
A rupture is when you have a full-thickness wound of the eyewall by blunt trauma.
A laceration occurs when you have a full-thickness wound of the eyewall by a sharp object
and there are 3 different ways that can occur with a laceration.
You can have an intraocular lesion which is a foreign body, you can have a penetrating injury
which is entrance wound only, or you can have a perforation which is both entrance and an exit wound.
Now alternatively to an open-globe injury, you can have what's called a closed-globe injury
in which the eyewall does not have a full-thickness wound.
Now here, you can have lamellar laceration or a contusion. In the setting of a lamellar laceration,
that is partial thickness wound of the eyewall while a contusion is a blow to the eyewall causing a partial-thickness wound.