Tag Archives: ophthalmology

Drop it like it’s Hot – Tetracaine eye drops following corneal abrasion?

Posted on by

Drop it like it’s Hot- A case presentation and critical appraisal on the use of tetracaine eye drops following corneal abrasion: A Medical Student Pearl

Claudia Cullinan

DMNB, Med 3

Reviewed by Dr. Kavish Chandra

Case:

It’s a sunny July afternoon and you are just starting your shift in the ED when a 25-year-old male presents with sudden onset of severe right eye pain. You bring him into the exam room, and he explains he ran into a tree branch. He is reluctant to open his eye due to the pain and his eye is watering uncontrollably. He also keeps his sunglasses on while you talk because his eye is now extremely sensitive to the bright ED lights.

The patient is visibly in a lot of distress, so you do a quick penlight exam and attempt to assess visual acuity to confirm there is no evidence of penetrating trauma.

At this point you suspect a corneal abrasion, so you move onto a slit lamp and fluorescein examination and add a tetracaine 0.5% (topical anesthetic) to the affected eye. The patient appears more comfortable within seconds. You are able to complete the exam with the patient sitting comfortably in the exam chair. There is no evidence of Seidel sign (streaming fluorescein caused by leaking aqueous humor) and no visible foreign body in the eye. You can visualise a linear yellow lesion along the lateral cornea when viewed with fluorescein under cobalt blue light and you are confident this is a simple corneal abrasion.

Figure 1. Corneal abrasion viewed with cobalt blue light after fluorescein staining. Accessed from DFOptometrists.com

You explain to the patient that he has a corneal abrasion, prescribe him erythromycin 0.5% ophthalmic ointment to be inserted into the affected eye QID for 5 days and encourage him to avoid rubbing his eyes. He can also take PRN ibuprofen if needed. He asks “That one eye drop made my eye feel so much better, can I have a bottle of that to bring home?”

You know he is talking about Tetracaine, and you remember learning about the controversy of using topical anesthetics for the outpatient treatment of corneal abrasions….what do you tell him?

Critical Appraisal : Short-term topical tetracaine is highly efficacious for the treatment of pain caused by corneal abrasions: a double-blind, randomized clinical trial. (2020)

Background:

Corneal abrasions are among the most common ophthalmic presentations to the emergency department (ED). They occur when the corneal epithermal becomes disrupted, such as when tiny foreign bodies land in your eye or when your new puppy accidentally scratches the surface of your eye.  Although corneal abrasions typically heal rapidly with minimal risk of complication, they are often VERY painful and can be extremely debilitating. There has been controversy on whether patients should be discharged home with topical anesthetics for short term management of corneal abrasions because of previously described safety concerns regarding toxicity. However, recent literature is beginning to surface suggesting there may be a role for short term topical analgesia following simple corneal abrasion, with appropriate follow up.

Figure 2. Anatomy of the cornea. Accessed form AAFP.org

Clinical Question:

How effective is the home use of topical tetracaine every 30 minutes PRN pain for 24 hours following corneal abrasion?

Reference

Shipman, S., Painter, K., Keuchel, M., & Bogie, C. (2021). Short-Term Topical Tetracaine Is Highly Efficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized Clinical Trial. Annals of Emergency Medicine, 77(3), 338–344.       https://doi.org/10.1016/j.annemergmed.2020.08.036

Study Overview:

Population: Patients 18-80 years old presenting to an urban ED in Oklahoma City with suspected acute corneal abrasion.

Intervention: 2mL bottle of Tetracaine 0.5% one drop applied q30 minutes PRN pain for a maximum of 24 hours + antibiotic ophthalmic solution (polymyxin B sulfate/ trimethoprim sulfate) 2 drops to affected eye q4h.

Control: 4 separate 0.5mL ampules of artificial tears (Systane) one drop applied q30 minutes PRN pain for a maximum of 24 hours + antibiotic ophthalmic solution (polymyxin B sulfate/ trimethoprim sulfate) 2 drops to affected eye q4h.

Outcome: Pain rating at 24-48h follow up.

Methods:

  • Prospective, double blind, randomised control trial of topical tetracaine vs control (artificial tears) in the ED following diagnosis of corneal abrasion in the ED.
  • Took place in an urban Oklahoma ED from 2015 to 2017.
  • One hundred and eleven patients were included and were randomly assigned to the treatment or control group.
  • The patients in both groups had similar baseline characteristics and baseline numeric rating scale (NRS) pain scores (0-10, 10 being the most pain).

Inclusion criteria:

Patients 18 to 80 years old, presenting to the ED with suspected acute corneal abrasion, and gave written informed consent.

Exclusion criteria:

Contact lens wearers, previous corneal surgery or transplant in the affected eye, presented more than 36 hours after their injury, had a grossly contaminated foreign body, had coexisting ocular infection, currently pregnant, retained foreign body, penetrating eye injury, receiving immunosuppression, allergy to study medication, unable to attend follow-up, unable to fluently read and speak English or Spanish, and any injury requiring urgent ophthalmologic evaluation.

Results:

Main outcomes at the 24-48hr follow up appointment:

  • The overall numeric rating scale (NRS) pain score was significantly lower in the tetracaine group compared to the control group (1 versus 8, P<0.001).
  • The number of patients found to have a small residual corneal abrasion on their follow up slit-lamp examination was similar between groups (18% in the tetracaine group and 11% in the control group).
  • There were only two complications in the tetracaine group (versus 6 in the control group), with similar rates of worsening corneal abrasions in both groups. All patients had normal healing after 10 days. No serious adverse outcomes were encountered.

Table 1. Patient baseline demographics and 24-48hr follow up data points.

Group Tetracaine (n=59) Control (n=59)
Age, y 35 (28-43) 38 (27-47)
Male patients, No. (%) 36 (61) 34 (58)
Baseline pain rating 7 (6-7.5) 7 (6-8)
24-48hr pain rating 1 (1-2) 8 (7-8)
No. of hydrocodone tablets recorded 1 7
Adverse Events, No (%) 2 (3.6) 6 (11)

Limitations and suggestions for future studies:

  • Although this was a double-blind study, there are two things that could have made patients aware of their treatment group. First, the control was packaged in 4 ampules and the treatment was packaged in a single bottle. Second, Tetracaine burns when administered to the eye and Systane (control) does not.
  • The study was slightly underpowered for the primary outcome of efficacy and certainly not powered to determine safety for rare adverse events associated with topical anesthetics. That being said, there are more patients in this trial demonstrating short term safety than previous care reports and series demonstrating tetracaine harm.
  • There was an extensive exclusion criterion, including patients who wear contacts (which are a common cause of corneal abrasions). By broadening the inclusion criteria, the results could be applied to a greater number of patients.
  • Patients were required to return for follow up at which time they were required to return their “study drops” so the drops cannot be abused. It would be more feasible to limit the amount of eye drops in the bottle so the patient does not have to return to the ED for bottle disposal.

Our conclusions:

Short term topical tetracaine is an efficacious analgesic for acute corneal abrasions, is associated with less hydrocodone use compared to control, and appears to be safe.

 

Case

Back to our original question…what do we tell our patient?

Provide him with a limited number of tetracaine drops and administer one drop in affected eye q30 minutes PRN pain for a maximum of 24 hours. Advise him to return to ED if his symptoms persist beyond 48 hours or get worse.

References

McGee, H. T., & Fraunfelder, F. (2007). Toxicities of topical ophthalmic anesthetics. Expert Opinion    on Drug Safety, 6(6), 637–640. https://doi.org/10.1517/14740338.6.6.637

Shipman, S., Painter, K., Keuchel, M., & Bogie, C. (2021). Short-Term Topical Tetracaine Is Highly        Efficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized             Clinical Trial. Annals of Emergency Medicine, 77(3), 338–344.       https://doi.org/10.1016/j.annemergmed.2020.08.036

Wipperman, J. L., & Dorsch, J. N. (2013). Evaluation and management of corneal abrasions.    American Family Physician, 87(2), 114–120.

Yu, C. W., Kirubarajan, A., Yau, M., Armstrong, D., & Johnson, D. E. (2021). Topical pain control for     corneal abrasions: A systematic review and meta-analysis. Academic Emergency Medicine, 28(8), 890–908. https://doi.org/10.1111/acem.14222

Continue Reading

Periorbital Inflammation – Red Eye – Red Flags

Posted on by

 

Medical Student Clinical Pearl

Alysha Roberts

MD Candidate, Class of 2021

Dalhousie University

@aeroberts_21

Reviewed & Edited by Dr David Lewis (@e_med_doc)

All case histories are illustrative and not based on any individual.

Case

A 40 year old male presents to the emergency department with a red, swollen eye. Without a known trigger, he had a one day history of progressive pain, erythema, and edema surrounding his left eye. He denied any fever or chills or visual changes, or headache. A thorough review of systems was negative, except for a complaint of worsening pain with extraocular movement.

On exam, he was afebrile and his vital signs were within normal limits. His visual acuity was normal, and pupils were equal and reactive to light. Extraocular movements were intact but associated with worsening pain. The periorbital tissue was erythematous, edematous, and hot to touch. Examination is limited by the severity of the patient’s swelling. Figure 1 illustrates an example of a patient with severe, unilateral eyelid swelling and erythema.

You suspect periorbital cellulitis.

Figure 1. Unilateral eyelid edema. Retrieved from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis

 

Periorbital Versus Orbital Cellulitis

Periorbital cellulitis, commonly referred to as pre-septal cellulitis, is an infection of the skin and soft tissue surrounding the orbit. Most commonly, it is the result of an infection spreading from the sinuses or from local trauma.1,2 It presents as a unilateral swelling of the eye-lid. Both periorbital and orbital cellulitis are most commonly caused by Staphylococcus Aureus and Streptococcus Pneumoniae. It is important to distinguish periorbital from orbital cellulitis, which is an infection of the orbit itself extending beyond the orbital septum. Orbital cellulitis is a sight-threatening emergency, and urgent imaging should be acquired in addition to consultation with ophthalmology or otolaryngology.3 Other complications of orbital cellulitis include orbital or subperiosteal abscess, and cavernous sinus thrombosis. Figure 2 illustrates the difference between periorbital (preseptal) and orbital cellulitis, as well as its complications.

Figure 2. Orbital anatomy and potential complications from orbital cellulitis. Retrieved from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis

Any patient with unilateral eyelid edema should be evaluated for red flags of orbital cellulitis, given its potential seriousness. Red flag signs and symptoms include:3,4

  • Painful or restricted extraocular movements
  • Reduced visual acuity
  • Relevant afferent pupillary defect
  • Diplopia
  • Proptosis
  • Chemosis
  • Severe headache

 

Differential Diagnosis

Other considerations for the differential diagnosis in a unilateral, swollen red eye include:5

  • Periorbital ecchymosis due to blunt trauma
  • Contact dermatitis secondary to local irritant
  • Atopic dermatitis due to allergic sensitivity
  • Orbital tumors

 

Risk Factors

Risk factors for periorbital and orbital cellulitis include:6

  • Sinusitis
  • Dental infection
  • Insect bite
  • Trauma

 

Periorbital cellulitis is most commonly caused by an insect bite in children, and trauma in adults. Comparatively, orbital cellulitis is most often the result of trauma in children, and sinusitis in adults.

 

Diagnostic Investigations

Patients who are febrile or appear unwell should have early initiation of IV antibiotics following blood cultures. Though periorbital cellulitis is a clinical diagnosis, if there is suspicion for orbital cellulitis a CT scan of the orbits and sinuses is the gold standard. Positive findings include inflammation of extraocular muscles, anterior globe displacement, and fat stranding. Inflammation of the sinuses should not be used to differentiate periorbital from orbital cellulitis, as up to 41% of cases of periorbital cellulitis may have CT evidence of sinusitis. Figure 3 displays a labelled CT image with common findings in orbital cellulitis.7

 

Figure 3. Orbital CT image with labels. Retrieved from https://ctscanmachines.blogspot.com/2018/07/ct-scan-of-periorbital-cellulitis.html

In addition to CT imaging, there may be a role for point of care ultrasound (PoCUS) in the diagnosis and management of periorbital and orbital cellulitis. However, research is currently lacking on whether its use may avoid the need for further diagnostic imaging.8 Findings from pediatric emergency medicine suggest that orbital ultrasound may be preferred in evaluating young patients who are unable to cooperate with a thorough physical examination.9 One important application of orbital PoCUS is in the assessment of orbital abscesses. Subperiosteal abscesses may complicate more than 50% of cases of orbital cellulitis, and are not reliably detected by CT.10 Additionally, orbital ultrasound may be an appropriate alternative in settings where advanced imaging is not available, in order to guide early initiation of antibiotics.

Orbital Abscess from – The PoCUS Atlas

 

 

Treatment Best Practices  

Antibiotic choice should be guided by local susceptibility guidelines. An appropriate choice would cover S. aureus, S. pyogenes, and anaerobes.11,12 In this case, we initiated intravenous ceftriaxone and metronidazole while awaiting CT results.

The following therapeutic guidelines are from Bugs and Drugs – It is recommended that that guidelines for therapy are accessed directly from their website or from other reputable sources.

Periorbital Cellulitis

 

Orbital Cellulitis

From Bug and Drugs

 

Case Conclusion

Given this patient’s complaint of increased pain with extraocular movement, a CT orbit was performed. Fortunately, there were no signs of orbital cellulitis. The patient was treated with IV ceftriaxone and metronidazole and scheduled to return to the emergency department the next day for re-evaluation and consideration of step-down to oral antibiotics.

Summary

Orbital cellulitis is a serious condition that should be carefully distinguished from periorbital cellulitis. On history, clinicians should ensure they inquire about recent sinus or dental infections, trauma to the orbit, or possible insect bites. Physical exam should carefully assess for signs of orbital cellulitis, including proptosis, chemosis, and limited extraocular movements. Any positive red flag or clinical suspicion warrants a CT scan of the orbits and sinuses to exclude orbital cellulitis.

Further Reading

Great photo article in Canadian Family Physician

Management algorithm

Patient Information Leaflet

 

 

 

References

  1. Preseptal and Orbital Cellulitis – Eye Disorders – Merck Manuals Professional Edition. (n.d.).Retrieved January 12, 2021, from https://www.merckmanuals.com/professional/eye-disorders/orbital-diseases/preseptal-and-orbital-cellulitis
  2. Lightning Learning: Orbital Cellulitis — #EM3: East Midlands Emergency Medicine Educational Media. (n.d.). Retrieved January 12, 2021, from https://em3.org.uk/foamed/7/5/2019/lightning-learning-orbital-cellulitis
  3. Periorbital cellulitis — entsho.com. (n.d.). Retrieved January 12, 2021, from https://entsho.com/periorbital-cellulitis
  4. Distinguishing Periorbital from Orbital Cellulitis. (2003). American Family Physician, 67(6), 1349.
  5. Differential Diagnosis of the Swollen Red Eyelid – American Family Physician. (n.d.). Retrieved January 12, 2021, from https://www.aafp.org/afp/2015/0715/p106.html
  6. Risk factors of preseptal and orbital cellulitis – PubMed. (n.d.). Retrieved January 12, 2021, from https://pubmed.ncbi.nlm.nih.gov/19149979/
  7. Ct Scan Of Periorbital Cellulitis – ct scan machine. (n.d.). Retrieved January 12, 2021, from https://ctscanmachines.blogspot.com/2018/07/ct-scan-of-periorbital-cellulitis.html
  8. Kang, T. L., Seif, D., Chilstrom, M., & Mailhot, T. (2014). Ocular ultrasound identifies early orbital cellulitis. Western Journal of Emergency Medicine, 15(4), 394. https://doi.org/10.5811/westjem.2014.4.22007
  9. Seguin, J., Le, C.-K., Fischer, J. W., Tessaro, M. O., & Berant, R. (2019). Ocular Point-of-Care Ultrasound in the Pediatric Emergency Department. Pediatric Emergency Care, 35(3), E53–E58. https://doi.org/10.1097/PEC.0000000000001762
  10. Derr, C., & Shah, A. (2012). Bedside ultrasound in the diagnosis of orbital cellulitis and orbital abscess. Emergency Radiology, 19(3), 265–267. https://doi.org/10.1007/s10140-011-0993-0
  11. Orbital Cellulitis – StatPearls – NCBI Bookshelf. (n.d.). Retrieved January 12, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK507901/
  12. Periorbital Cellulitis – StatPearls – NCBI Bookshelf. (n.d.). Retrieved January 12, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK470408/
Continue Reading