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RECOGNIZING OPHTHALMOLOGIC EMERGENCIES Benjamin R. Doolittle, M.D., M. Div. WEEK 22 Learning Objectives: 1. To recognize the difference between those ophthalmologic diseases which may be managed by a primary care physician and those that necessitate emergent referral 2. To identify the differential diagnosis of acute visual loss and acute visual change 3. To understand the fundamentals of treatment and pathophysiology for ocular emergencies CASE ONE: Pain, Purulence, and Photophobia You arrive in your clinic in the morning to discover a 25-year-old woman who shares, “I have had a cold the past two days and woke up this morning with my right eye all red and gross. I can’t stop itching it. What is going on, and what are you going to do to help me?" Your history further reveals mild photophobia, discomfort, but no feeling of a “grain of sand” on her eye. Your exam shows 20/20 vision, normal extra-ocular movements, and normal papillary reflex. Her right conjunctiva is hyperemic and inflamed. Indeed, you note a yellow discharge that has matted her eyelid. Questions: 1. What is going on, and what are you going to do? This is bacterial conjunctivitis. It is not an emergency. It is caused by both gram positive and negative bacteria, and easily treated with topical antibiotics. Topical gentamicin or tobramycin eyedrops four times a day for 7-10 days has been recommended. Polytrim – a sulfa – is also widely used and inexpensive. Topical fluoroqinolones are used for more severe infections. Keep this case in mind as we continue with our busy day in the office. CASE TWO: Sudden, Unilateral, Painless Loss of Vision Later in the morning, a long-time patient of yours comes into the office. He is 55 with severe diabetes. Although diligent with his illness, he has had long stretches of time with no follow-up or lab work due to inconsistent health insurance. He shares, “I was driving to work when suddenly I couldn’t see out of my right eye. It just went blank. I saw the stop sign, and then suddenly it wasn’t there anymore. I came right over to have you check it out. You note that his last Hgb A1C, six months ago, was 9.9. He has never seen an ophthalmologist. 2. What are the six features of the eye exam (hint: it’s in the article!), and what are some aspects to which you should pay particular attention? The six parts of the eye exam are the following: visual acuity, visual field, pupils, extraocular muscles, anterior segment, and posterior segment. In this particular case, the patient’s visual acuity should be carefully assessed. As noted in the article, if the vision is less than 20/40, having the patient read the eye chart through a pinhole will give an approximation of the best corrected vision. If the patient still cannot see through the pinhole, the next step is to assess if the patient can count the examiner’s fingers. If unable to do so, the next step is to discern if the patient can detect hand movement, and if unable to do so, determine if the patient can detect light. In a patient with severe diabetes, this story is most concerning for vitreous hemorrhage with retinal detachment; amaurosis fugaxis is also a consideration. CASE TWO CONTINUED: On exam, you discover that the patient cannot see the eye chart with the right eye, cannot count the fingers on your hand, and cannot detect hand motion. When you shine a penlight in the right eye, the patient reports he can detect the light. The visual field exam is compromised by his inability to see, but he reports he can see the light in all visual fields. The papillary exam and extra-ocular exam are essentially normal. You note no lesions on the conjunctiva or the cornea. You hesitate with the ophthalmoscope – you never had great technique as a medical student. Nonetheless, you are able to make out the retina on the left eye. On the right eye however, you note that the red reflex is obscured, and discerning the retinal vessels is difficult. 3. What is your diagnosis, and what are you going to do? As above, the most likely diagnosis of SUDDEN, UNILATERAL, and PAINLESS loss of vision in a person with diabetes is vitreous hemorrhage due to disorganized retinal vessels (e.g., fragile microaneurysms, neovascularization, exudates). Retinal detachment is also a possibility but usually presents with a different story (“rays of light” usually on the peripheral visual fields, and may be acute or subacute). Amaurosis fugax – occlusion of the retinal artery – results in sudden, unilateral loss of vision but would NOT result in the clinician being unable to visualize the retina. The management for all of the above is immediate evaluation by an ophthalmologist. Vitreous hemorrhage is often managed expectantly, but may require laser coagulation. If time permits, it might be helpful to review the proper technique of the ophthalmoscope. CASE THREE: Sudden, Unilateral, Painful, Loss of Vision Late in the evening – you are wrapping up your schedule - an elderly woman presents to your office in moderate distress, clutching the left side of her face. She was in the backyard at dusk when her left eye suddenly began to hurt. “All at once, my eye became so incredibly painful. In fact, I have a headache that is so bad that I threw up twice.” On exam, you note that the visual acuity of her left eye is 20/200. Her visual fields appear intact but are compromised by her poor vision. Her left pupil is slightly dilated, unreactive to light, and has an irregular border. Her extraocular muscles are intact. The anterior segment reveals a hazy, edematous cornea. The patient is not compliant with a posterior segment exam due to discomfort. 4. What is your leading diagnosis? This story is most consistent with acute angle-closure glaucoma. The NEJM article does a nice job of explaining the different etiologies of PAINFUL and PAINLESS visual loss. The ophthalmic branch of the Vth nerve innervates the eye’s surface - the cornea, conjunctiva, and the iris. Thus, PAINFUL loss of vision usually point towards problems of the anterior chamber, whereas PAINLESS loss of vision suggest posterior segment disease (i.e. vitreous or retina). Other etiologies of acute and painful change in vision include corneal abrasion, keratitis, iridocyclitis, and conjunctivitis from an allergic, viral, or bacterial source. Perhaps the most ominous is an infection with herpes simplex, which often presents with symptoms similar to a corneal abrasion. This can be a tricky diagnosis to make, but the dendritic ulceration is most easily visualized with fluorescein (see case 4 below and Figure 10 in the article). Also, important to mention, is that the eye is the “window to the body.” Thus, when discussing visual compromise, we must consider such systemic disease as tuberculosis, collagen vascular disease (Reiter’s syndrome, temporal arteritis, sarcoid, etc.) and syphilis. 5. Describe the physiology and treatment of acute angle-closure glaucoma. Acute glaucoma usually occurs in ambient light and when the pupil needs to dilate, more commonly occurring among patients who are far-sighted due to the relatively shorter axial length of their globe. In a healthy eye, the vitreous flows from the posterior segment into the anterior segment, then out through the delicate, trabeculated canals into the venous system. When the pupil dilates, the iris bunches up or “accordions” against the outflow tract of the vitreous (the Canal of Schlemm). Acute angle-closure glaucoma occludes this outflow system, which results in a rapid rise in intra-ocular pressure. In fact, gentle palpation through closed lids may reveal that the affected eye is more firm than the normal one. The treatment consists of emergent laser iridectomy to relieve the blockage. 6. What is the Take-Home Point? Any severe eye pain or a visual defect merits strong consideration for immediate ophthalmologic evaluation, especially if corneal abrasion or conjunctivitis are ruled out by history and physical. It is not enough to have our patients “call their eye doctor tomorrow,” but rather, it is beholden upon us to arrange transfer for such patients. In the same way that we would transfer a patient with active chest pain to the ER for evaluation of unstable angina, so we are called to transfer patients with severe eye pain to an ophthalmologist. CASE FOUR: Sudden, Unilateral, Painful, Decrease in Vision Your last patient of the day is a 30-year-old gentleman who presents with a red, painful right eye, decreased visual acuity, and photophobia that has become progressively worse over the past two days. He does not wear contact lenses, cannot recall any trauma, but notes, “There does feel like there’s something on my eye ball.” On exam, his visual acuity in his right eye is 20/70. His right conjunctiva are markedly inflamed, but without purulent discharge. You do not notice any abnormalities of the cornea. He is unable to hold still for the retina exam. You are concerned about the degree of his pain, in a situation that is very different from bacterial conjunctivitis. You apply topical tetracaine, which relieves his discomfort, and fluorescein dye. You notice an irregularly shaped ulcer, which is “dendritic” or “spiculated”. (If one was to steer away from medical jargon, one might say that it looks like the shoreline of the Chesapeake Bay or perhaps Rhode Island, see for yourself in Figure 10 of the NEJM article!). “Hmm,” you say to yourself. “What do I do now?” 7. What do you do now? What do you think is the leading diagnosis? This is most consistent with herpes simplex keratitis. See question 4 above for the differential. Herpes infection is a sight-threatening infection, which often can mimic other, less insidious etiologies, such as idiopathic or allergic inflammation, as well as TB and connective tissue disease. The treatment for herpes simplex is trifluridine (Viroptic) nine times a day x 21 days or vidarabine ointment. Unfortunately, there is a 30-50% recurrence in two years, but this rate decreases with the administration of acyclovir 400mg bid. The challenge is that IF the lesion looks benign, a less-informed physician may be tempted to treat with a topical steroid, resulting in unchecked progression of the herpes infection. The stakes are high, and one must have a high index of suspicion and low threshold to refer. One quality that increases our concern is the presence of a “hypopyon” – a layer of white cells in the anterior chamber suggestive of pus or any corneal infiltrate (see Figure 9). If one suspects herpes simplex, immediate referral is warranted. References: 1. Shingleton, BJ & O’Donoghue, MW. Blurred vision, NEJM; 2000; 343 (8): 556-562. Additional References: 1. Leibowitz, HM. The Red Eye, NEJM; 2000; 343(5): 345-351. 2. Wilhelmus, KR, Beck, RW, Moke, PS, Acyclovir for the prevention of recurrent herpes simplex virus eye disease, NEJM 1998; 339:300-06.