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A case of Herpetiform Keratitis- Clinical evaluation and important considerations.

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A case of Herpetiform Keratitis- Clinical evaluation and important considerations: A Resident Clinical Pearl

Bonnie He, PGY1

Ophthalmology, Dalhousie University

Reviewed by: Dr. Cherie Adams

Copyedited by: Dr. Mandy Peach

Case

A 68-year-old female presented to SJRH Emergency Department with a three-day history of atraumatic worsening of right eye pain, photophobia, and decreased vision. She denied any experience of flashing lights or “curtain falling”. She reported a long-standing history of glaucoma for which she was previously prescribed brimonidine (alpha-agonist) ophthalmic drops and was prescribed travoprost (prostaglandin) ophthalmic drops approximately one week prior to presentation. Additional ophthalmologic history revealed used of glasses, but not contact lenses, and bilateral cataract surgery two years previously. Of particular note, she recounted an episode of “sores from her upper lip along the side of her nose to right lower eyelid” in the past for which she was treated with oral valacyclovir. Further history positive for hypertension, for which she is prescribed ramipril, and type 2 diabetes mellitus, for which is is prescribed metformin. She is a retired schoolteacher, non-smoker, social drinker and denies any recreational drug use.
Visual acuity from 20 feet with spectacle correction revealed was 20/100 on the right (OD) and 20/30+1 on the left (OS). Her intraocular pressures were OD 17 and OS 19. Examination revealed mild upper and lower eyelid edema and moderate conjunctival injection. Fluorescein staining of the right cornea revealed four small dendritic epithelial defects (Figure 1) at about the 6 o’clock position. External and slit lamp examination of the left eye was normal. Fundoscopic examination to check the optic disc, macula, retinal vessels, and periphery were deferred.

Figure 1A: 4 small dendritic epithelial lesions can be seen at the 6’oclock position.

 

Figure 1B: Classic dendritic corneal epithelial lesions 17.

OPHTHALMOLGIC ASSSESSMENT:

Ocular complaints are common in emergency care settings. Yet, the quantity and quality of ophthalmology education varies significantly across Canada, with both medical students and residents report receiving insufficient ophthalmic medical education from medical education curricula.1-3
Proper history and physical examination taking skills are crucial to the appropriate management of patients with a red eye. The American Academy of Ophthalmology recommends the 8-point physical exam as a systematic approach to any eye problems:

  1. Visual acuity
    • Position the patient 20ft or 6m away from the Snellen chart to test for distance vision
    • Document whether it is their best corrected visual acuity, (ie. did they have their glasses or contact lens on at the time of the exam)
  2. Pupils
    • In dim room light, check for:
      1. Direct response by looking for pupil constriction in the eye being shined
      2. Consensual response by looking for pupil constriction in the other eye (eye that is not being shined)
  • Rapid Afferent Pupillary Defect (RAPD) with the swinging light test by shining light back and front between eyes
  1. Extraocular motility and alignment
    • Conduct a “H test” to test for the 9 cardinal positions of gaze by tracing out the letter “H” in the air while monitor their eyes for 3 S’s: speed, smoothness, and symmetry
    • Ask patient to follow your finger with their eyes while keeping their head still in the center and note for any double vision at certain gazes
  2. Intraocular pressure
    • The Icare tonometer requires no local anesthetic
    • Insert probe into tonometer and anchor the tonometer to the seated patient’s eyebrow.
    • Slowly bring tonometer probe towards patient light until the light turns green – now you’re ready to press the button that will automatically measure the patient’s intraocular pressure
  3. Confrontation visual fields
    • At about 1 arm’s-length away, test each eye individually by holding up 1 or 2 fingers and ask patient how many fingers they see
    • Ask patient to close their OS and fixate on your nose. Close your OS to assess with your open OD.
    • To check OS, ask the patient to close their OD and fixate on your nose. Close your OD to assess with your open OS.
  4. External examination
    • Assess for any obvious globe rupture, ecchymoses, deformities or lesions around the eye
    • Check to see if there’s any ptosis (lid drooping)
  5. Slit lamp examination (watch this video to learn how to perform a slit lamp exam: https://www.youtube.com/watch?v=gHW5OYj1Gf8
    • Assess for the following structures
    • Lids/lashes/lacrimal system: edema, erythema, lesions
    • Conjunctiva/sclera: injection, subconjunctival hemorrhage
    • Cornea: foreign body, fluorescein stain + cobalt blue light to assess corneal integrity (ie. corneal abrasions, herpetic dendrites), Seidel test (leakage of aqueous humour)
    • Iris: round (normal) vs. peaked (abnormal)
    • Anterior chamber: any hyphema, hypopyon, cells, flare
    • Lens: opacity
  6. Fundoscopic examination
    • In the emergency department, fundoscopy is typically undertaken in the undilated eye.
    • May consider dilating the eye with tropicamide (dilating drop) to visualize the back of the eye with the slit lamp or direct ophthalmoscope
    • Assess for the following structures:
      1. Optic nerve: cup-to-disc ratio, pallor, symmetry between eyes
      2. Macula: foveal light reflex
  • Vessels: Arteriovenous (AV) nicking, silver or copper wiring,
  1. Periphery: bleeding

DISCUSSION:

Given the patient’s endorsed history suggestive of ipsilateral V2 herpes zoster and classic dendritic corneal lesions, the leading differential diagnosis for her acute on chronic ocular pain in this case would be zoster keratitis, though herpes keratitis should also be considered, particularly in patients with identified history and recent episode of orolabial cutaneous HSV. Interestingly, she was started on travoprost for her glaucoma a week prior to her presentation. Topical ocular hypotensive agents, including travoprost, are known to have a myriad local and systemic side effects including: superficial punctate keratitis, corneal erosion, bradycardia, hypotension, and bronchoconstriction, are common.4,5 However, of particular interest in this case,  multiple clinical and animal studies have reported that topical prostaglandins for ocular hypertension are culprits  associated with herpes simplex virus (HSV) keratitis or varicella-zoster virus (VZV) keratitis.6-13 It is thought that prostaglandin analogues such as travaprost may induce the reactivation of HSV keratitis by releasing endogenous prostaglandins in the iris and ciliary muscles.9,14-16 Therefore it could also be very well possible that she may have developed HSV keratitis.

 

Irrespective of which differential was truly causing this patient’s symptoms the antiviral treatment for zoster ophthalmicus and HSV keratitis are the same: valocylcovir 1g TID PO x 7 days (or acyclovir 800mg po five times daily if cost of valcyclovir is prohibitive) and arrangements were made for next-day ophthalmologist consultation.

 

BOTTOM LINE:

Always take a thorough ophthalmologic history for patients with ocular complaints, including complete medication history.

Always ask about contact lens use in a history in any patient with a painful red eye.

Always conduct a complete physical exam for patients with ophthalmologic complaints using the AAO 8-point framework described above.


REFERENCES

  1. Sim D, Hussain A, Tebbal A, Daly S, Pringle E, Ionides A. National survey of the management of eye emergencies in the accident and emergency departments by senior house officers: 10 years on—has anything changed? Emerg Med J. 2008;25(2):76-77. http://emj.bmj.com/content/25/2/76.abstract. doi:10.1136/emj.2007.049999.
  2. Noble J, Somal K, Gill HS, Lam W. An analysis of undergraduate ophthalmology training in Canada. Canadian Journal of Ophthalmology. 2009;44(5):513-518. http://www.sciencedirect.com/science/article/pii/S0008418209801130. doi:https://doi.org/10.3129/i09-127.
  3. Gostimir M, Sharma RA, Bhatti A. Status of Canadian undergraduate medical education in ophthalmology. Canadian Journal of Ophthalmology. 2018;53(5):474-479. http://www.sciencedirect.com.ezproxy.library.ubc.ca/science/article/pii/S0008418216309553. doi:https://doi-org.ezproxy.library.ubc.ca/10.1016/j.jcjo.2017.11.015.
  4. Inoue K. Managing adverse effects of glaucoma medications. Clinical ophthalmology (Auckland, N.Z.). 2014;8:903-913. https://pubmed.ncbi.nlm.nih.gov/24872675 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4025938/. doi:10.2147/OPTH.S44708.
  5. Anwar Z, Wellik SR, Galor A. Glaucoma therapy and ocular surface disease: current literature and recommendations. Curr Opin Ophthalmol. 2013;24(2):136-143. doi:10.1097/ICU.0b013e32835c8aba [doi].
  6. Kroll DM, Schuman JS. Reactivation of herpes simplex virus keratitis after initiating bimatoprost treatment for glaucoma. Am J Ophthalmol. 2002;133(3):401-403. doi:S0002939401013605 [pii].
  7. Wand M, Gilbert CM, Liesegang TJ. Latanoprost and herpes simplex keratitis. Am J Ophthalmol. 1999;127(5):602-604. doi:S0002939499000501 [pii].
  8. Alm A, Grierson I, Shields MB. Side effects associated with prostaglandin analog therapy. Surv Ophthalmol. 2008;53 Suppl1:93. doi:10.1016/j.survophthal.2008.08.004 [doi].
  9. Soomro MZ, Moin M, Attaulla I. Latanoprost and Herpetic Keratitis. Pakistan Journal of Ophthalmology. 2011;27(4).
  10. Kothari MT, Mehta BK, Asher NS, Kothari KJ. Recurrence of bilateral herpes simplex virus keratitis following bimatoprost use. Indian J Ophthalmol. 2006;54(1):47-48. doi:10.4103/0301-4738.21617 [doi].
  11. Ekatomatis P. Herpes simplex dendritic keratitis after treatment with latanoprost for primary open angle glaucoma. Br J Ophthalmol. 2001;85(8):1008-1009. doi:10.1136/bjo.85.8.1007a [doi].
  12. Morales J, Shihab ZM, Brown SM, Hodges MR. Herpes simplex virus dermatitis in patients using latanoprost. Am J Ophthalmol. 2001;132(1):114-116. doi:S0002939401010121 [pii].
  13. Villegas VM, Diaz L, Izquierdo NJ. Herpetic keratitis in a patient who used two different prostaglandin analogue ophthalmic solutions: a case report. P R Health Sci J. 2008;27:348+. https://link.gale.com/apps/doc/A189052227/HRCA?u=anon~6a050068&sid=googleScholar&xid=2c140d29.
  14. Dios Castro E, Maquet Dusart JA. Latanoprost-associated recurrent herpes simplex keratitis. Arch Soc Esp Oftalmol. 2000;75(11):775-778.
  15. Gordon YJ, Yates KA, Mah FS, Romanowski EG. The effects of Xalatan on the recovery of ocular herpes simplex virus type 1 (HSV-1) in the induced reactivation and spontaneous shedding rabbit models. J Ocul Pharmacol Ther. 2003;19(3):233-245. doi:10.1089/108076803321908356 [doi].
  16. Kaufman HE, Varnell ED, Toshida H, Kanai A, Thompson HW, Bazan NG. Effects of topical unoprostone and latanoprost on acute and recurrent herpetic keratitis in the rabbit. Am J Ophthalmol. 2001;131(5):643-646. doi:S0002939400009107 [pii].
  17. Yu, Hubert (2019) Canadiem Medical Concepts: Approach to Corneal Disorders in the ED

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Lateral Canthotomy

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Lateral  Canthotomy – A Medical Student Clinical Pearl

Scott Clarke

Med III, Class of 2022

Dalhousie Medical School New Brunswick (DMNB)

Reviewed by Dr. Fraser MacKay

Copyedited by Dr. Mandy Peach

 

Case:

You are a clinical clerk working your first shift in a busy emergency department when you hear overhead those heart stopping, adrenaline pumping words: “Trauma team activation, room 24”. You arrive to find an unconscious 45 year old male. Report from the paramedics tells you there was a workplace accident whereby a tree had fallen and struck the patient in the face. The team works swiftly and efficiently to secure an airway and stabilize his vitals. From the team leader, your role is to perform a brief neurological exam.

Despite heavy sedation and swelling in the face, you are able to identify significant proptosis of his left eye. His right pupil is reactive to light but you notice his left responds significantly less and there is a positive relative afferent pupillary defect (RAPD). You relay your findings to the team lead and suggest an urgent CT scan of the head.

 

Before departing for CT your attending asks you – what diagnosis are you concerned for? What clinical findings support this diagnosis?

Orbital Compartment Syndrome1

Vision threatening condition where intraocular pressure (IOP) exceeds 40 mmHg.

Clues on exam:

  • Impaired extraocular movements (from a retrobulbar hematoma)
  • Decreased visual acuity
  • RAPD
  • Blown Pupil

Your attending agrees there is concern for orbital compartment syndrome and ophthalmology should be urgently paged – do you wait for CT to confirm retrobulbar hematoma?

No – You quickly grab a tono-pen and measure the intraocular pressure to be 50mmHg. In order to save this patient’s vision, a lateral canthotomy is immediately performed in an attempt to temporarily release pressure before definitive hematoma evacuation can occur.

Procedural Overview:

Equipment:

  1. Tono-pen
  2. Hemostat
  3. Local anesthesia
  4. Curved iris scissors (or scalpel)

Anatomy review:

The globe of the eye is held firmly in place by the strong tarsal plates and the medial and lateral canthal ligaments (Figure 2). By dividing the lateral canthus (inferior limb or both inferior and superior limbs), the globe has room to expand which can greatly reduce pressure3.

Figure 2: Anatomy of the components holding the globe of the eye4.

Procedure5:

  1. Clean the lateral portion of the eye using chlorhexidine or a similar solution.
  2. Inject 2-3cc of 1% lidocaine with 1:100,000 epinephrine into the site of the lateral canthus primarily for hemostasis
  3. Insert the hemostat into the lateral portion of the eye and crush the lateral canthus. Hold this for 30-45 seconds. This will devascularize the tissue resulting in further reduction in bleeding.
  4. Using the curved iris scissors (or scalpel), cut the lateral canthus to the rim of the globe, ~1-2cm at a slight downward angle.
  5. The inferior limb of the lateral canthal ligament will be able to be palpated and resembles a guitar string. This should be divided as well.
  6. If significant intraocular pressure remains, divide the superior limb of the lateral canthal ligament as well.
  7. Reassess ocular pressure.

 

Once the procedure is completed you wait 5 minutes and reassess the intraocular pressure. You notice that it has gone from 50mmHg to 38mmHg. The patient is sent for CT head which confirms a retrobulbar hematoma.

You follow up with the patient during his hospital stay and discover his vision eventually returns to his normal pre-injury.

 

Keys to remember6:

Indications include trauma patients with:
– Proptosis
– Impaired ocular movements
– Elevated Intraocular pressure, usually >40mmHg
– Decreased visual acuity
– RAPD

Ideally performed within 60-120 min of features of ischemia to the optic nerve1.

Absolute contraindication:
– Globe rupture

Medical treatment can also be initiated with the goal to help decrease intraocular pressure 1:

  • mannitol
  • acetazolamide
  • pilocarpine
  • timolol

See below for video of a lateral canthotomy on an actual patient (viewer discretion advised):

References

  1. Helman, A. Swaminathan, A. Austin, E. Strayer, R. Long, B, McLaren, J. Brindley, P. EM Quick Hits 24 – Lateral Canthotomy, Cannabis Poisoning, Hyperthermia, Malignant Otitis Externa, BBB in Occlusion MI, Prone CPR. Emergency Medicine Cases. December, 2020. https://emergencymedicinecases.com/em-quick-hits-december-2020/. Accessed [May 5, 2021].
  2. Retrobulbar Hematoma from Warfarin Toxicity and the Limitations of Bedside Ocular Sonography – The Western Journal of Emergency Medicine. https://westjem.com/videos/retrobulbar-hematoma-from-warfarin-toxicity-and-the-limitations-of-bedside-ocular-sonography.html. Accessed March 29, 2021.
  3. Amer E, El-Rahman Abbas A. Ocular Compartment Syndrome and Lateral Canthotomy Procedure. J Emerg Med. 2019;56(3):294-297. doi:10.1016/j.jemermed.2018.12.019
  4. Chan D, Sokoya M, Ducic Y. Repair of the Malpositioned Lower Lid. 2017. doi:10.1055/s-0037-1608711
  5. How to do Lateral Canthotomy – Eye Disorders – Merck Manuals Professional Edition. https://www.merckmanuals.com/en-ca/professional/eye-disorders/how-to-do-eye-procedures/how-to-do-lateral-canthotomy. Accessed March 29, 2021.
  6. Lateral Canthotomy – YouTube. https://www.youtube.com/watch?v=Qs5Smx-cxbo. Accessed March 29, 2021.
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