Rosen & Barkin's 5-Minute Emergency Medicine Consult (771 page)

DIAGNOSIS

• Categorize visual loss by the properties associated with the decrease in visual function
  
• Transient (<24 hr):
  
  • Minutes:
    
    • Transient ischemic attack = amaurosis fugax (unilateral)
      
    • Vertebrobasilar artery insufficiency (bilateral)
      
  • Minutes to hours:
    
    • Migraine
      
    • Sudden BP changes
      
• Persistent (>24 hr):
  
  • Painless: Sudden:
    
    • Retinal artery or vein occlusion
      
    • Vitreous hemorrhage
      
    • Retinal detachment
      
    • Optic neuritis
      
    • Giant cell arteritis
      
    • Cerebral infarct
      
  • Painless: Gradual (weeks to years):
    
    • Cataract
      
    • Presbyopia
      
    • Refraction errors
      
    • Open-angle glaucoma
      
    • Chronic retinal disease
      
    • Macular degeneration
      
    • Diabetic retinopathy
      
    • CMV retinopathy
      
    • CNS tumor
      
  • Painful:
    
    • Corneal abrasion, ulcer, burn, or foreign body
      
    • Angle-closure glaucoma
      
    • Optic neuritis
      
    • Iritis/uveitis/endophthalmitis
      
    • Keratoconus with hydrops
      
    • Orbital cellulitis/abscess
      
• Monocular: Pathology anterior to optic chiasm
  
• Binocular: Pathology posterior to optic chiasm
  
• Associated with systemic neurologic symptoms of visual field defects:
  
  • CVA (especially posterior or occipital circulation)
    
  • Mass lesion (pituitary adenomas, aneurysm, meningioma, other tumors)
    
• Malingering/hysteria
  

• Decreased vision:
  
  • Loss of vision
    
  • Blurry vision
    
  • Double vision:
    
    • Horizontal or vertical
      
• History of trauma
  
• Use of corrective lenses:
  
  • Contacts
    
  • Glasses
    
• Prior eye surgery or problems
  
• Eye pain
  
• Conjunctival redness or discharge
  
• New floaters
  
• Flashing lights
  
• Pain with eye movement
  
• Key elements to determine:
  
  • Acute or gradual onset
    
  • Length of symptoms
    
  • Transient vision loss or permanent
    
  • Binocular or monocular
    
  • Degree of vision loss
    
  • Painful or painless
    
  • Other comorbidities
    

• Ophthalmologic:
  
  • Visual acuity
    
  • Pupil exam
    
  • Afferent papillary defect
    
  • Confrontational visual field exam
    
  • Extraocular muscle function
    
  • Slit-lamp exam
    
  • Intraocular pressure (Tonometry)
    
  • Fundoscopy:
    
    • Optic nerve swelling
      
    • Pale retina with a cherry-red spot
      
• Cardiovascular:
  
  • Murmurs
    
  • Carotid bruits
    
  • Temporal artery tenderness
    
• Neurologic exam:
  
  • Complete exam for other deficits
    
  • Optic chiasm and intracerebral lesions
    
  • Occipital and posterior circulation lesions
    
• General:
  
  • Signs of immune, endocrine, or toxic disorders
    

Thorough history and physical exam

• May be obtained to determine extent of other comorbidities in association with vision loss (i.e., diabetes, cardiovascular disease)
  
• Erythrocyte sedimentation rate if giant cell arteritis is suspected
  

• Tests should be directed toward the suspected etiology of visual loss
  
• Dilated fundus exam may be performed to assess for posterior segment disease
  
• Temporal artery biopsy may be obtained if giant cell arteritis is suspected
  
• Brain CT, MRI, MRA, and transcranial Doppler may be used to evaluate neurologic symptoms and vertebrobasilar artery
  
• Urgent cardiac and carotid US if a retinal artery occlusion is diagnosed
  
• Facial CT may be used to evaluate extent of traumatic injuries
  

• Trauma
  
• Neurologic lesion
  
• Infectious
  
• Cardiovascular
  
• Toxic/metabolic
  
• Autoimmune
  

TREATMENT

• Chemical burns:
  
  • Begin copious irrigation with water or saline
    

• Direct therapy toward cause of visual loss
  
• Ophthalmology consultation for visual loss with an uncertain diagnosis
  
• 3 conditions for which identification and treatment must begin within minutes:
  
  • Central retinal artery occlusion
    
  • Chemical burn
    
  • Acute angle-closure glaucoma
    

• Clinical criteria:
  
  • Unilateral, painless, dramatic vision loss
    
  • Afferent pupillary defect
    
  • Pale fundus with a cherry-red spot (macula)
    
  • Counting fingers to light perception in 94% of patients
    
• Therapy:
  
  • Immediate ophthalmology consultation
    
  • Maneuvers and medications to lower intraocular pressure, allowing the embolus to move to the periphery:
    
    • Ocular massage: Direct pressure to eye for 5–15 sec then sudden release, repeat for 15 min
      
    • Acetazolamide: 500 mg IV or PO
      
    • Topical β-blocker
      
    • Anterior chamber paracentesis by an ophthalmologist
      
  • Referral for cardiac and carotid artery workup
    
  • Rule out giant cell arteritis
    

• Clinical criteria:
  
  • Alkali worse than acids
    
  • White eye (vessels have already sloughed) worse than red eye (vessels are intact)
    
  • Examples: Mace, cements, plasters, solvents
    
• Therapy:
  
  • Topical anesthetic
    
  • Copious irrigation of the eyes with LR or NS (nonsterile water is acceptable if others not available); minimum of 30 min
    
  • Goal: Neutral pH at 5–10 min after ending irrigation
    
  • Do not try to neutralize acids with alkalis or vice versa
    
  • Evert lids and use moist cotton-tipped applicator to sweep furnaces for residual chemical precipitants
    
  • Dilate with cycloplegic (atropine, cyclopentolate, tropicamide)
    
  • Do not use phenylephrine; vasoconstricts already ischemic conjunctival blood vessels
    
  • Erythromycin ointment q1–2h
    
  • Artificial tears q1h
    
  • Check intraocular pressure
    

• Signs and symptoms:
  
  • Unilateral, painful vision loss
    
  • Nausea, vomiting, headache
    
  • Cornea injected, edematous
    
  • Mid-dilated, sluggish/nonreactive pupil
    
  • Swollen, “steamy” lens
    
  • Cell, flare in a shallow anterior chamber
    
  • Increased intraocular pressure (>20 mm Hg)
    
• Therapy:
  
  • Topical β-blocker
    
  • Topical prostaglandin analog
    
  • Acetazolamide
    
  • Topical α-2 agonist
    
  • Pilocarpine
    
  • Mannitol: If no decrease in IOP after 1 hr
    

• Antibiotic drops:
  
  • Ciprofloxacin 0.3%: 1–2 gtt q1–6h
    
  • Gentamicin 0.3%: 1–2 gtt q4h
    
  • Ofloxacin 0.3%: 1–2 gtt q1–6h
    
  • Levofloxacin 0.5%: 1–2 gtt q2h
    
  • Polymyxin (Polytrim) 1 gtt q3–6h
    
  • Sulfacetamide 10%, 0.3%: 1–2 gtt q2–6h
    
  • Tobramycin 0.3%: 1–2 gtt q1–4h
    
  • Trifluridine 1%: 1 gtt q2–4h
    
• Antibiotic ointments:
  
  • Bacitracin 500 U/g 1/2 in ribbon q3–6h
    
  • Ciprofloxacin 0.3%: 1/2 in ribbon q6–q8h
    
  • Erythromycin 0.5%: 1/2 in ribbon q3–6h
    
  • Gentamicin 0.3%: 1/2 in ribbon q3–4h
    
  • Neosporin 1/2 in ribbon q3–4h
    
  • Polysporin 1/2in ribbon q3–4h
    
  • Sulfacetamide 10%: 1/2 in ribbon q3–8h
    
  • Tobramycin 0.3%: 1/2 in ribbon q3–4h
    
  • Vidarabine 1/2 in ribbon 5 times per day
    
• Mydriatics and cycloplegics:
  
  • Atropine 1%, 2%: 1–2 gtt/day to QID
    
  • Cyclopentolate 0.5%, 1%, 2%: 1–2 gtt PRN
    
  • Homatropine 2%: 1–2 gtt BID–TID
    
  • Phenylephrine 0.12%, 2.5%, 10%: 1–2 gtt TID–QID
    
  • Tropicamide 0.5%, 1%: 1–2 gtt PRN dilation
    
• Corticosteroid–antibiotic combination drops (with ophthalmology consultation):
  
  • Prednisolone (Blephamide) 1–2 gtt q1–8h
    
  • Hydrocortisone/neomycin/bacitracin/polymyxin B (Cortisporin) 1–2 gtt q3–4h
    
  • Dexamethasone/neomycin/polymyxin B (Maxitrol) 1–2 gtt q1–8h
    
  • Prednisolone/gentamicin (Pred-G) 1–2 gtt q1–8h
    
  • Dexamethasone/tobramycin/chlorobutanol (TobraDex) 1–2 gtt q2–26h
    
• Glaucoma agents (always with ophthalmology consultation):
  
  • α-2 agonists:
    
    • Brimonidine 1% 1 gtt TID
      
    • Apraclonidine 1% 1 gtt TID
      
  • β-blocker:
    
    • Betaxolol 0.25%, 0.5%: 1–2 gtt BID
      
    • Carteolol 1%: 1 gtt BID
      
    • Levobunolol 0.25%, 0.5%: 1 gtt QD–BID
      
  • Carbonic anhydrase inhibitor:
    
    • Acetazolamide 500 mg PO/IV QD–QID
      
  • Miotic (parasympathomimetic):
    
    • Pilocarpine 0.25%, 0.5%, 1%, 2%, 3%, 4%, 6%, 8%, 10%: 1–2 gtt TID–QID
      
  • Osmotic agent:
    
    • Mannitol 1–2 g/kg IV over 45 min
      
  • Prostaglandin analog:
    
    • Latanoprost 0.005%: 1 gtt QD
      
• Only if mechanical closure is ruled out:
  
  • Timolol 0.25%, 0.5%: 1 gtt BID
    

FOLLOW-UP