As a medical student on a core clinical rotation, you are given a unique opportunity to immerse yourself in a discipline. Whether you are on the hospital floors during your internal medicine rotation, in the emergency department, or on the pediatrics unit, you are tasked every day with studying, shadowing, and doing all things related to that specialty. It is equally as exciting as it is daunting, and for medical students who have a passion for ophthalmology, it is easy to let your interests take a back seat to the everyday grind.
While it is undeniably critical to learn, experience, and grow as a future physician during each of your core rotations, your zeal for ophthalmology shouldn’t be put on the back burner. As a matter of fact, I think your interests in ophthalmology can be fostered on each of your core clinical rotations in unique ways. From different pathologies to exam techniques, knowing the ophthalmology related to your core clinical rotation can turn you into a true all-star.
The emergency department (ED) quite literally has it all. From a devastating comminuted tibial fracture to a simple upper respiratory infection, you never quite know what you will encounter when you pull back the curtain. One thing is for sure, a core rotation in emergency medicine offers ample opportunity for you to foster your passions in ophthalmology.
Here is a guide to the common pathologies and clinical situations seen during your emergency medicine core rotations and how you can get hands-on ophthalmology experience during them. In this piece, I’m going to break down some of the more common ocular pathologies and clinical situations you can encounter in the ED and how, as a student, you can use this rotation to grow as an aspiring ophthalmologist.
Gain experience performing ophthalmologic exams
Though slit lamps and indirect headsets may be hard to come by in the ED, this doesn’t mean you can’t get hands-on ophthalmologic experience during this core clinical rotation.
As third- and fourth-year students, you will likely have the autonomy to see patients on your own and complete a physical exam. This is a chance to develop skills that will be the foundation for much of your medical career. It is also a chance to practice and learn to do many parts of a comprehensive bedside ophthalmologic exam.
In particular, the ophthalmologic portion of your exam is crucial to any neurologic workup in the ED, and including it in your physical exam will show your attendings you are a thorough and thoughtful future clinician. Any complaint in which a neurologic workup is indicated (headache, dizziness, minor head injury, etc.) is a reasonable time to include some ophthalmic workup in your exam.
Students should check their patient's pupillary light reflex, look for a rapid afferent pupillary defect, and assess extraocular movements and confrontational visual fields. These exams can quickly assess cranial nerves (CN) II, III, IV, and VI, and identifying abnormalities here can be crucial to diagnostics and management.
Take this scenario, a mass lesion pushing on CN III can masquerade as a patient presenting with a migraine. As a student, you can quickly recognize further imaging is necessary when you notice a fixed and dilated pupil, as well as an absent pupillary reflex. The examples go on:
- While checking extraocular movement, an abducens nerve palsy can reveal a chronic bleed causing increased intracranial pressure (ICP). The abducens nerve has a relatively long course around the brainstem and is at higher risk of injury from ICP, inflammation, and trauma.1
- A relevant afferent pupillary defect (RAPD) can indicate optic neuritis and help you and your attending make a difficult diagnosis like multiple sclerosis.2
- Different types of nystagmus during extraocular movement or a head impulse, nystagmus, Test of Skew examination (HiNTs) can help decide if your patient’s dizziness is due to benign paroxysmal positional vertigo (BPPV) or a more insidious central lesion.
If a patient presents with an ophthalmic specific complaint—blurry vision, for example—the bedside physical exam can be further expanded:
- Check visual acuity using a Snellen chart
- Learn to use the Tonopen to assess intraocular pressure
- Get your hands on the direct ophthalmoscope to access the lens for cataracts or try to visualize the retina.
If you’re short on time but still want to make a good impression with the ophthalmologist, check the vital signs of ophthalmology: pupils, vision, and pressure. It’s likely to be one of the first things your attending will want to know.
Pathologies encountered in the emergency department
Ocular trauma and open globe
An open globe injury is one possible outcome of a patient with ocular trauma. A common clinical presentation may be a patient presenting to the ED after a head-on collision with airbag deployment. The blunt pressure of the airbag can cause a rapid increase in intraocular pressure (IOP), resulting in a full-thickness tear of the eye wall.
Other presentations include an ocular foreign body such as a small projectile from a construction site or a laceration from a sharper object that penetrates the eye like scissors.
A classic physical exam finding, and a favorite of test writers, is a “teardrop” shaped pupil upon physical exam, but globe ruptures can be less obvious in real practice. This teardrop shape of the pupil usually occurs when the iris prolapses through the globe defect and distorts the pupil’s shape. In the ED, your main goal is to prevent further damage to the eye prior to repair. The eye should be covered with a shield and the patient should receive pain medication and antiemetics.
Any sort of vomiting or Valsalva because of pain could increase IOP acutely and cause expulsion of the contents of the globe. While in the ED, the patient should also get a CT scan to assess the extent of damage, be started on broad-spectrum antibiotics to prevent endophthalmitis, and tetanus prophylaxis should be considered.
As a student, you can help by performing a visual acuity test on this patient. The acuity test now is important as it helps set a baseline against which improvement can be measured.3 In addition, patients with open globe injury should be kept NPO as surgery to repair the globe within 24 hours is indicated.
The most common presentation of chemical injury is an ocular burn in a young child, ages 1-2, coming from a residential setting.4 Burns can cause severe defects in the conjunctiva, corneal epithelium, or deeper eye structures so prompt action is required. Regardless of the exact situation, one thing holds true, irrigation is king. By irrigating you balance out the pH in the eye, limiting damage.5
A Morgan lens and intravenous tubing connected to a normal saline bag is the preferred setup for irrigation. In the absence of a Morgan lens, you can be more creative and use an IV saline bag, cut off the end of the tubing, and irrigate through a nasal cannula.6 Be sure to irrigate from the medial portion of the eye and wash outwards towards the lateral side.
Once you get started, don’t plan on going anywhere, you could be irrigating for hours and as a student, it will be your job to hold that irrigation set up in place. You can continuously measure the pH of the tears of the eye using a litmus paper, and irrigation should continue until pH normalizes (around 6.5-7.5).7
All ocular burns are dangerous, however, alkaline burns carry a worse prognosis as they cause liquefactive necrosis that can penetrate deep into the globe. An acidic burn causes coagulative necrosis which will form an eschar and limit its own penetration.
A patient comes in complaining of severe pain and photophobia in both eyes after a day out skiing, or maybe a child comes in with the same complaint after a day spent playing in the puddles of a neighborhood sprinkler. This clinical picture is highly suspicious of photokeratitis.
Photokeratitis is caused when prolonged or intense exposure to UV light causes the corneal epithelial cells to slough off, leaving underlying nerves exposed.8 Think of it similar to a sunburn, but in your patients’ eyes. The good news is the cornea generally heals in 24-72 hours and in the meantime, treatment is generally supportive. Patients can be given artificial tears, as well as an ocular ointment, such as topical erythromycin to aid in comfort and prevent a secondary infection.9
An important thing to note is that photokeratitis may not ‘light up’ right away on the exam. If you use a fluorescein stain and quickly check the eye with the ED woods lamp, an epithelial defect or abrasion may be missed. In a suspected photokeratitis or small corneal abrasion, give the stain some time to settle in. Microtrauma defects take more time to uptake dye and reveal themselves.
Acute angle-closure glaucoma
Glaucoma is a common eye pathology related to elevated intraocular pressures which eventually damage the optic nerve. The eye is continuously making and draining aqueous humor via the ciliary body and trabecular meshwork and Canal of Schlemm, respectively.
When the ability of the eye to drain this humor is impaired, pressures will rise. In the ED, patients can present with what is referred to as acute angle glaucoma when the drainage of the aqueous humor is interrupted by an anterior movement of the iris and pupil. Symptoms include blurry vision, seeing halos of light, headache, nausea, and severe eye pain.
An exam can show conjunctival injection, a hazy or edematous cornea, a fixed mid-dilated pupil, and elevated intraocular pressures (usually well above 21 mm Hg). After a diagnosis is made in the ED, management to lower the pressure can begin. Therapy will vary depending on circumstance and the patient’s medical history but everything aims to lower aqueous humor production (topical glaucoma drops, IV acetazolamide) and increase the aqueous outflow( pilocarpine).10
Unfortunately, acute angle-closure glaucoma can cause permanent vision damage within a matter of hours. I’d say that’s a good reason to have a strong understanding of the presentation and management of this pathology while walking the floor on your ED rotation.
The end result of many of your eye-related encounters will be an ophthalmology consult. As a student, this is an opportunity to get a mini crash course in ophthalmology straight from the source. When the ophthalmologist on call comes to the ED, don’t be afraid to introduce yourself and ask to observe their consult.
In my experience, students who take the initiative and show genuine interest are often rewarded.
At a minimum, you will get to observe a thorough ocular exam and make a connection with an ophthalmology resident or attending.
The ED is an exciting place and will keep you on your toes. Take advantage of the opportunities to hone your ophthalmic knowledge and skills, grow as a future physician, and most importantly enjoy your rotation.
- Graham C, Mohseni M. Abducens Nerve Palsy. [Updated 2022 Apr 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482177/
- Germann CA, Baumann MR, Hamzavi S. Ophthalmic diagnoses in the ED: optic neuritis. Am J Emerg Med. 2007 Sep;25(7):834-7. doi: 10.1016/j.ajem.2007.01.021. PMID: 17870491
- Andreoli MD, C. M. (n.d.). Open globe injuries: Emergency evaluation and initial management. Retrieved May 02, 2021, from https://www.uptodate.com/contents/open-globe-injuries-emergency-evaluation-and-initial-management?source=history_widget
- Haring RS. Epidemiologic trends of chemical ocular burns in the united states. JAMA ophthalmology. 10/2016;134(10):1119-1124. doi: 10.1001/jamaophthalmol.2016.2645.
- Spector J. Chemical, thermal, and biological ocular exposures. Emergency medicine clinics of North America. 02/2008;26(1):125-136. doi: 10.1016/j.emc.2007.11.002.
- Linn, Michelle. “Trick of the Trade: Eye Irrigation Setup.” ALiEM, 20 Feb. 2019, https://www.aliem.com/trick-of-trade-eye-irrigation-setup/.
- Saari KM. Management of chemical eye injuries with prolonged irrigation. Acta ophthalmologica. Supplementum. 1984;161(s161):52-59. doi: 10.1111/j.1755-3768.1984.tb06784.x
- Bergmanson, J. P. (1990). Corneal damage in photokeratitis--why is it so painful?. Optometry and vision science: official publication of the American Academy of Optometry, 67(6), 407-413.
- Moon, Christina. “Photokeratitis.” EyeWiki, 25 Feb. 2022, https://eyewiki.aao.org/Photokeratitis.
- Langridge, Colton. “Acute Angle Closure Glaucoma: ED-Relevant Management.” EmDOCs.net - Emergency Medicine Education, 21 Apr. 2017, http://www.emdocs.net/acute-angle-closure-glaucoma-ed-relevant-management/#:~:text=Acute%20angle%20closure%20glaucoma%20(AACG,as%201%20in%20100%20Asians.
- Murray D. Emergency management: angle-closure glaucoma. Community Eye Health. 2018;31(103):64.