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COVER ARTICLE/CME Urgent Care 2(8):20, 2007 In managing eye disease, your vision is as important as your patient’s. What you observe with a slit-lamp, ophthalmoscope, and the naked eye is the key to making an accurate diagnosis. Eyesight is a gift that most patients take for granted, until their vision becomes acutely compromised. When that happens, patients often present to urgent care facilities instead of eye clinics. But even though most of these facilities have slit-lamps and ophthalmoscopes, not all urgent care physicians feel comfortable managing eye emergencies because they lack formal ophthalmology training. This article will help you prepare for your next eye emergency by reviewing the signs and symptoms, diagnosis, and treatment of the nine important conditions you may likely encounter. PERFORMING THE
EYE EXAMINATION Diagnosing eye disease requires keen eyes on the part of the physician. Although a patient history can provide important diagnostic clues, examination with a slit-lamp, direct ophthalmoscope, and the naked eye is critical. Urgent care physicians should develop a routine checklist for eye examinations when assessing a patient with visual complaints (see box below).
First, check visual acuity in each eye with the patient wearing his best distance glasses or contact lenses to correct refractive errors. Any unexplained decrease in vision or asymmetrical acuity between the eyes requires a comprehensive work-up to determine the cause. If the patient misplaced his glasses or doesn’t have his contacts in, use a pinhole occluder to approximate the best possible visual acuity. Next, test the patient’s peripheral vision in each eye by confrontation, using your fingers or a small red object. The patient should look at the physician’s pupil with the other eye covered as peripheral vision is tested in each eye. The presence of a scotoma or field defect suggests underlying neurologic disease. The pupils should then be examined for reactivity to light, symmetry, and size. A swinging flashlight test between the two pupils can be performed to look for an afferent pupillary defect (Marcus Gunn pupil), suggesting optic nerve disease. Also inspect the motility of the extraocular muscles in all directions to rule out muscle restriction or paralysis. Now, examine the internal structures of the eye with a slit-lamp. Both eyelids should be everted to look for foreign bodies embedded in the conjunctiva. Use a topical anesthetic drop to facilitate examination of patients with severe eye pain. However, never prescribe topical anesthetics for corneal pain management because repeated use can be toxic to the cornea. Also, be sure to lock these medications away because they are often stolen and abused by patients with chronic eye pain. The cornea is normally transparent, and small opacities or foreign bodies can easily be missed if a slit-lamp isn’t used. Fluorescein dye or paper strips that stain the cornea when used with a cobalt blue light on the slit-lamp will help you visualize epithelial defects and perforations. The anterior chamber (the space between the cornea and the iris) is normally clear and devoid of blood or inflammatory cells. The presence of any cells, fluid, or debris in the anterior chamber requires further investigation and consultation with an ophthalmologist. Finally, inspect both optic nerves and the central retina (fovea) with a direct ophthalmoscope in a dark room. Darkness helps dilate the pupils and improve visualization. If you wear corrective lenses or contact lenses, put them on before examining the patient. Then set the direct ophthalmoscope dial to zero and focus on the pupil, turning the dial in the direction that offers the clearest view of the optic nerve as you approach the patient’s eye. The following clinical scenarios describe eye emergencies often seen in urgent care clinics. Once diagnosed, all of these patients should be referred to the emergency department or to an ophthalmologist, when appropriate. CASE #1: FLOATERS, FLASHES, AND A MOVING SHADOW A 30-year-old woman who previously underwent Lasik eye surgery to correct myopia presents to an urgent care clinic with floaters and flashes of light in her right eye. She says these symptoms have persisted for four days and are worse with eye movement. During the past few hours, the patient has also noted a moving gray shadow in the periphery of her temporal visual field. There is no associated headache or nausea, and her visual acuity is 20/20 in each eye. Her medical history is significant for migraine headaches, but she has never had these visual symptoms while experiencing a migraine. What is the patient’s most likely diagnosis? The answer is retinal detachment. As people age, the vitreous begins to liquefy and detach from the retina, causing the perception of floaters. In some patients, such as those who are highly myopic, the normal process of the vitreous detaching from the retina may cause a peripheral horseshoe tear in susceptible areas of the retina. The tear allows fluid within the vitreous to accumulate under the retina and cause a detachment. When the retina is partially detached, the patient may notice a shadow (scotoma) during eye movement that corresponds to the torn retina. A retinal detachment is considered an ophthalmic emergency because the detachment can progress to the fovea and cause central vision loss (see image below). A direct ophthalmoscope examination alone is insufficient to view the peripheral retina and should never be used to diagnose or rule out a retinal tear or detachment. If you suspect a detached retina, consult an ophthalmologist immediately, who can confirm the diagnosis of a retinal tear or detachment by using an indirect ophthalmoscope.
CASE #2: SUDDEN COMPLETE UNILATERAL VISION LOSS An 84-year-old man presents to an urgent care clinic with vision loss, headache, and fatigue. Examination reveals light perception only in the left eye and 20/20 vision in the right eye; a Marcus Gunn pupil is seen in the left eye. Examination by direct ophthalmoscope reveals a diffuse, pale left retina except for a bright red spot in the fovea (see image below). The right eye is normal.
What is the patient’s diagnosis? This patient’s symptoms are typical of a central retinal artery occlusion. When an elderly patient presents with sudden unilateral vision loss, always suspect this problem. It is believed that the retina can tolerate no more than 90 minutes of ischemia, so consult an ophthalmologist immediately, before permanent vision loss occurs. There is a strong association between temporal (giant cell) arteritis and retinal artery occlusions. Severe, irreversible vision loss can occur rapidly in the other eye due to the inflammatory nature of temporal arteritis that affects the blood vessels to both eyes. If you suspect temporal arteritis, especially in the presence of vision loss, immediately initiate systemic corticosteroid treatment and obtain an erythrocyte sedimentation rate (ESR), then consult an ophthalmologist. The normal ESR value in men can be approximated by dividing the patient’s age by two; for women, add 10 to the patient’s age and divide by two. If the ESR is elevated, presume that the patient has temporal arteritis. If the ESR is normal, a C-reactive protein concentration should be ordered, particularly if the patient has constitutional symptoms that suggest temporal arteritis, such as fever, weight loss, jaw pain, myalagias, scalp tenderness, and a prominent temporal artery. The diagnosis of temporal arteritis is confirmed by a temporal artery biopsy, which should be performed outside the urgent care setting. Start systemic corticosteroid treatment immediately, especially when a patient presents with visual symptoms along with temporal arteritis. Any delay in initiating systemic steroids risks permanent vision loss in both eyes. A temporal artery biopsy should be performed within one week of starting corticosteroid treatment to decrease the possibility of a false-negative result. Finally, patients with retinal artery occlusions are at risk for coronary artery arteriosclerosis and should be referred to their internist or a cardiologist for a systemic work-up. CASE #3: HYPERACUTE PURULENT DISCHARGE IN BOTH EYES A 22-year-old man presents to an urgent care clinic with significant, purulent discharge from both eyes (see image below). He doesn’t wear contact lenses and hasn’t suffered any ocular trauma. Visual acuity is 20/50 in each eye. The eyelids and conjunctiva are swollen with yellow, purulent discharge. The cornea appears normal in both eyes on fluorescein staining. The preauricular lymph nodes, however, appear very tender and enlarged.
What is the probable diagnosis? This patient’s symptoms are typical of gonococcal conjunctivitis. Suspect this condition when a patient presents with sudden, hyperacute, purulent conjunctivitis. A Gram stain of the discharge should be ordered immediately. Gram-negative intracellular diplococci indicate Neisseria gonorrhoeae. Once this diagnosis is made, refer the patient to an emergency department immediately. If left untreated, Neisseria species can rapidly penetrate an intact cornea, infect the internal eye, and cause a corneal perforation within 24 hours. Treatment of this bacterial conjunctivitis is different from treatment of conjunctivitis from other causes, such as Streptococci and Haemophilus species, because intravenous antibiotics are required in addition to topical antibiotics to achieve therapeutic levels in the eye. These patients must be hospitalized and monitored to prevent the development of a corneal perforation. They should also be tested for HIV and treated for Chlamydia because of the high rate of coinfection. Any sexual partners should also receive medical attention. CASE #4: PAINFUL RED EYE AND HISTORY OF INTRAOCULAR SURGERY An 81-year-old woman presents to an urgent care clinic with a four-day history of discharge, pain, and redness in her left eye. She states that an ophthalmologist surgically placed a “valve” in this eye two years ago to lower her eye pressure from glaucoma. Visual acuity is 20/400 in the left eye and 20/30 in the right eye. Direct inspection reveals a very injected and swollen left eye, and slit-lamp examination shows a white layer of fluid accumulating in the bottom of the anterior chamber (see image below).
What is the most likely diagnosis? The answer is bacterial endophthalmitis. When a patient with a history of intraocular surgery (such as cataract or glaucoma surgery) presents with a red, painful eye, an intraocular infection must be ruled out. Any microbial infection within the eye is called endophthalmitis. The appearance of a milky-white layer in the bottom of the anterior chamber (hypopyon) is caused by densely packed inflammatory white blood cells. This is the key sign in recognizing endophthalmitis. Postoperative endophthalmitis can occur days, weeks, months, or even years after eye surgery. Surgical glaucoma procedures in particular carry an increased risk for intraocular infection. Endophthalmitis is a medical emergency that requires the expertise of an ophthalmologist, who will inject broad-spectrum antibiotics into the eye and possibly perform a surgical vitrectomy to remove the infected vitreous and eye fluid. CASE #5: PAINFUL RED EYE IN A SOFT CONTACT LENS WEARER A 21-year-old college student presents to an urgent care clinic complaining of eye pain on awakening. He admits to regularly wearing his soft contact lenses while sleeping, against the advice of his ophthalmologist. The left eye reveals significant conjunctival injection and some mild discharge. Fluorescein staining reveals a large defect in the central cornea with an underlying white haze (see image below).
What do you think the diagnosis is? The answer is bacterial keratitis, also known as corneal ulcer. Any corneal epithelial defect with an underlying white opacity is considered to be a corneal ulcer (bacterial keratitis) until proven otherwise. There is a high incidence of gram-negative corneal ulcers (Pseudomonas aeruginosa) in patients who wear soft contact lenses while sleeping. If not properly treated, these patients have a high risk of developing a disabling corneal scar and a corneal perforation because the microbial enzymes can rapidly melt the cornea. Refer this patient to an ophthalmologist, who will treat the corneal ulcer by discontinuing use of the contact lenses and starting hourly topical fortified broad-spectrum antibiotics. Topical corticosteroids are contraindicated because they cause the cornea to melt further. Don’t instill topical antibiotics before referral. The ophthalmologist will obtain a bacterial culture of the cornea to help guide antibiotic therapy. Instilling antibiotics in the eye beforehand can affect the microbial growth on the corneal culture. CASE #6: PAINFUL RED EYE AND A METALLIC CORNEAL FOREIGN BODY A 27-year-old male metal welder presents to an urgent care clinic with eye pain, tearing, and a foreign body sensation. A metallic foreign body is noted in the cornea periphery. Before attempting to remove the particle, you instill topical fluroscein into the eye and note a change in the dye color (see image below).
The diagnosis here is obvious. But what is the appropriate next step in the management of this patient? The correct answer is the last one. Metal welders and people in similar occupations are often exposed to high-velocity metallic particles that can injure the eye. Your first priority is to rule out a perforating eye injury (ruptured globe). Examine each eye carefully for the following signs of such an injury: irregular pupil, deformed globe, eyelid swelling, conjunctival hemorrhage and swelling, hyphema, absent red reflex of the pupil, proptosis, and any full-thickness eyelid laceration. Fluorescein dye helps stain the cornea and reveal epithelial defects and perforations when used with a cobalt blue light or a Wood’s lamp. A protective shield, not a pressure patch, should be placed over the eye to prevent any pressure that could result in additional injury. The patient should be made comfortable and receive appropriate systemic pain medications to prevent further eye damage. Administer broad-spectrum intravenous antibiotics and give a tetanus booster, if indicated. Once the diagnosis of a ruptured globe has been made, all subsequent efforts to examine the eye should be deferred to the ophthalmologist, who may recommend that an orbital computed tomography (CT) scan be performed to determine the full extent of the eye injury. Minor corneal trauma in the absence of a ruptured globe can be managed in the urgent care setting. If the physician has good manual dexterity, small foreign bodies embedded superficially in the corneal periphery can be safely removed using a slit-lamp. The patient should receive topical antibiotics after the procedure as prophylaxis against infection. Make sure the patient’s tetanus immunization status is up-to-date. Foreign bodies or rust rings embedded deeply in the cornea or in the central visual axis should only be removed by an ophthalmologist. CASE #7: SUDDEN UNILATERAL EYE PAIN WITH NAUSEA AND VOMITING A 61-year-old woman awakens in the middle of the night with severe right eye pain, nausea, and vomiting. In the urgent care clinic, her visual acuity is noted to be “counting fingers at one foot” in the right eye and 20/25 in the left eye. The right eye is quite injected and the cornea appears hazy. The right pupil shows minimal reaction to light and appears slightly dilated. The right anterior chamber appears narrow (see image below). The left eye appears completely normal.
What is the patient’s probable diagnosis? The correct answer is acute angle-closure glaucoma, which should be suspected whenever a patient has nausea, vomiting, eye pain, and blurred vision. This is an ophthalmic emergency because the optic nerve is at risk for damage from any prolonged, elevated eye pressure. Findings include a red eye, a fixed and nonreactive pupil, and a cloudy cornea. The key diagnostic sign is elevated intraocular pressure. Devices that accurately measure eye pressure (Goldmann applanation tonometer, Schiøtz tonometer, and Tono-Pen) require the use of topical anesthetic eye drops first to prevent eye pain and corneal injury. If the eye pressure is greater than 30 mm Hg or if there is a marked difference in pressure (greater than 20 mm Hg) between the two eyes, suspect angle-closure glaucoma. If a tonometer isn’t available, another method of detecting asymmetrical eye pressure caused by a unilateral attack of angle-closure glaucoma is to palpate each eye with the eyelids closed (see image below). The eye with the acutely elevated pressure will feel firmer than the normal eye. Although this technique is highly subjective and often inaccurate, it offers urgent care physicians a safe alternative for evaluating eye pressure.
Initial treatment for angle-closure glaucoma consists of topical 1% apraclonidine and 500 mg of systemic acetazolamide to lower the eye pressure, usually administered in urgent care clinics under the guidance of an ophthalmologist. Once the eye pressure is medically lowered, an ophthalmologist uses a laser to create a new passageway through the peripheral iris to allow the aqueous fluid to flow freely. The peripheral iris of the other eye should also receive laser treatment as a preventive measure to avoid a potential CASE #8: SUDDEN HEADACHE, DROOPY EYELID, AND DOUBLE VISION A 37-year-old woman presents to an urgent care clinic with acute onset of a headache and a droopy left eyelid. Visual acuity is 20/20 in each eye. When you lift up her left upper eyelid, you discover that the eye is deviated outward and downward (see image below). When you assess ocular motility, the left eye can’t elevate, adduct (move toward the nose), or depress. The only motility present in the eye is the ability to look away from the nose. The left pupil also appears dilated compared to the right pupil. The right eye shows no motility deficits.
What is your diagnosis? This patient has a complete third-nerve palsy. She should be referred to an emergency department immediately for a neurosurgery consultation for possible intracranial aneurysm, magnetic resonance imaging and angiography of the brain, and possibly a cerebral angiogram. The third cranial nerve travels within the subarachnoid space between the posterior cerebral and superior cerebellar arteries. This is also near the posterior communicating artery, an area prone to the development of vascular brain aneurysms. This patient has paresis of five extraocular muscles, which is the cause of the droopy eyelid and paralysis of all eye motility except lateral gaze (innervated by the sixth cranial nerve). The pupil is dilated because the parasympathetic fibers that cause pupil constriction travel on the outside sheath of the third cranial nerve and are highly susceptible to compression by an adjacent aneurysm. A microvascular infarct (for example, in a patient with diabetes or hypertension) affects the inner fibers of the third cranial nerve and doesn’t cause pupil dilation. These patients will have an incomplete third-nerve palsy, which causes a droopy eyelid and eye muscle paresis; however, their pupils will be of symmetrical size. Nevertheless, there have been reports of intracranial aneurysms masquerading as incomplete third-nerve palsies. Patients with a presumed microvascular infarct of the third nerve should be monitored closely by a neurologist for a possible underlying intracranial aneurysm. CASE #9: HEADACHE, BLURRED VISION, AND PERIPHERAL SCOTOMAS A 17-year-old girl presents to an urgent care clinic complaining of episodic headaches, blurry vision, and seeing black peripheral spots in both eyes for the past two months. Her visual acuity is 20/60 in each eye, but she has never worn glasses or contact lenses. She has no history of migraine headaches but admits to taking doxycycline for the last two months to treat her facial acne. Both optic nerves are visualized with a direct ophthalmoscope (see image below).
What do you think is wrong with this patient? This patient has pseudotumor cerebri, a diagnosis of exclusion, which is probably caused by the recent use of doxycycline. When a patient presents with a headache and visual disturbances, always inspect both optic nerves with an ophthalmoscope to rule out papilledema, a term used to describe optic disc swelling secondary to increased intracranial pressure. If papilledema is present, measure the patient’s blood pressure to rule out malignant hypertension as a potential cause of the optic nerve swelling and refer the patient to an emergency department for a neurology consultation. The neurologist should obtain a noncontrast head CT scan to rule out any intracranial hemorrhage or mass. If the brain imaging tests are negative, an analysis of the cerebral spinal fluid should be considered to rule out any infectious or malignant etiology. As a general rule, all patients with visual complaints should have their visual acuity tested in each eye. In the absence of any previous refractive error (myopia, hyperopia, or astigmatism, as in this case), an unexplained decrease in vision must be investigated. WORKING WITH AN OPHTHALMOLOGIST The urgent care physician should never hesitate to consult an ophthalmologist when the diagnosis is in question or when examining the eye is difficult. I highly recommend that urgent care physicians spend a day or even a week with an ophthalmology colleague in an eye clinic. This is an excellent opportunity to acquire valuable knowledge on eye disease and to gain experience in using the slit-lamp and ophthalmoscope. An increased awareness and recognition of eye disease among urgent care physicians will result in improved patient care that ultimately restores and preserves eyesight.
Suggested Reading
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