Case Study 11 - CC: Acute pain and burning in L eye

Patient History

HPI:
31 year-old male, auto-mechanic presenting to the emergency department (ED) with injury to eye/face after a mishap at work. He was working under the hood of a car on the engine when the battery exploded and sprayed onto his face. He immediately felt pain in his left eye and the surrounding skin. Pain is a burning quality, severe 10/10, and is worsening. He is also having difficulty opening his left eye and is photophobic. His right eye is uninjured and he has no other injuries. Immediately after the injury, he flushed his eyes in the emergency eye flush at work and was then urgently driven to the nearest ED. Upon arrival, irrigation of the eyes was begun.

Past Ocular History:
No prior eye surgeries, trauma, amblyopia or strabismus OU

Ocular Medications:
None

Past Medical History:
None

Surgical History:
None

Past Family Ocular History:
Negative for macular degeneration, glaucoma or blindness.

Social History:
5-10 drinks per week, non-smoker

Medications:
None

Allergies:
Penicillin – hives

ROS:
Denies recent illness or any new CNS, heart, lung, GI, skin or joint symptoms.

Ocular Exam

Visual Acuity (cc):
OD: 20/20
OS: 20/200

IOP (tonoapplantation):
OD: 13 mmHg
OS: 16 mmHg

Pupils:
R equal, round and reactive; hazy view to the L anterior chamber

Extraocular Movements:
Full OU. No nystagmus.

Confrontational Visual Fields:
Full to finger counting R, grossly full but inconsistent responses L.

External:
Normal R; erythematous and excoriated skin surrounding L eye.

Slit Lamp:

Lids and Lashes	Normal OD; erythematous upper and lower lid; erythematous upper and lower lid OS
Conjunctiva/Sclera	Normal OD; 3+ injected and 1+ chemosis 360 degrees with area of epithelial loss (fluorescein exam); erythematous upper and lower lid OS
Cornea	Clear OD; diffuse edema with central epithelial defect 75% of corneal area OS; erythematous upper and lower lid OS
Anterior Chamber	Deep and quiet OD; hazy view; erythematous upper and lower lid OS
Iris	Normal OD, grossly normal OS; erythematous upper and lower lid OS
Lens	Clear OU; erythematous upper and lower lid OS
Anterior Vitreous	Clear OD, difficult to assess OS; erythematous upper and lower lid OS

Dilated Fundus Examination:

OD	Clear view, CDR 0.2 with sharp optic disc margins; flat macula with normal foveal light reflex; normal vessels and peripheral retina
OS	Red reflex but no view of retinal details

Other:
pH of tears at arrival to ED: 6
pH of tears after 3L of normal saline irrigation of the L eye: 7

Diagnosis
Chemical (sulfuric acid from car battery) burn to eye

Discussion

Differential Diagnosis:
This patient has suffered a chemical burn to the L eye. Chemical burns to the eye are a true ocular emergency and requires immediate treatment to avoid further damage and irreversible vision loss. Other conditions that would cause a large corneal abrasion are in the differential diagnosis (mechanical trauma, contact lens-related abrasion, unprotected welding injury). Corneal infections (viral, bacterial, fungal) should also be considered.

Definition:
Agents causing the chemical burn can be classified as either alkali, acidic or neutral. Alkali substances are lipophilic and penetrate the ocular tissues more quickly than acidic or neutral substances, leading to deeper penetration into the eye and more severe damage than an acidic agent. Common alkali substances causing ocular burns include lye (Drano), mixed cement, and ammonia (cleaning products). Acidic substances include sulfuric acid (car batteries), nail polish and vinegar. Neutral substances include substances such as pepper spray. Chemical burns may injure most anterior portions of the eye including the lid, conjunctiva, and cornea. Damage to inner ocular structures such as the iris, ciliary body, lens and trabecular meshwork can also occur, especially with longer exposures and with alkali substances. Severe burns might result in corneal scarring, severe dry eyes, cataracts and increased intraocular pressure (glaucoma). Patients with severe conjunctival and corneal scarring due to chemical burns might not be candidates for corneal transplants and suffer long-term decreased visual acuity.

Examination:
Important initial information to ascertain includes what substance caused the injury, how long was the exposure, how long ago the exposure occurred, and how has the injury been treated prior to presentation. Irrigation of the affected eye should commence even prior to an eye exam, and should continue until the pH of tears OS at arrival to ED: 6. After, a full eye examination should be performed in both eyes, paying special attention to the fornices (including the eversion of the underside of the upper lid to ensure no chemical particulates), the conjunctiva, cornea and anterior chamber. Whitening of the conjunctiva is associated with a poorer prognosis as it indicates the burn has lead to significant vascular damage.

Treatment:
When a chemical burn is suspected, irrigation of the eye should begin immediately. Isotonic sterile saline is the irrigant of choice (especially if in the ED), however, water can be used if this is all that is available. Constant irrigation of at least 10-15 minutes is recommended. Irrigation should continue until the pH of the tears has neutralized to around 7. Sweeping the fornix of the eye with a sterile cotton tip should be performed in all cases to help remove retained particles. Topical anesthetics can make the irrigation more tolerable. Even with immediate and sufficient irrigation, permanent damage can still occur. Once the pH is neutralized, an eye exam can then occur. Burns may be treated with artificial tears, topical antibiotics, topical steroids, dilating drops, and pain medication, depending on the extent of damage done. More severe injuries may require glaucoma medications to maintain a normal IOP or surgical intervention and life-long ophthalmic care.

1. When initially evaluating a person with exposure of a chemical substance to the eye, what should be done first?
   • Get a good history to help determine what kind of substance got in the eye
   • Check the vision, pressure, and do a slit lamp exam to determine the extent of damage done by the substance
   • Begin immediate ocular irrigation
   • Getting the patient some oral pain medications so the patient is more comfortable and able to undergo an ocular evaluation
2. Which substance is likely to cause the most severe chemical burn in the eye?
   • Nail polish
   • Battery acid
   • Drano (lye)
   • Pepper spray
   • Vinegar
3. What type of ocular finding would be less likely due to a chemical burn?
   • Conjunctival whitening
   • Corneal Scarring
   • Cataract
   • Increased ocular pressure
   • Retinal detachment

References/Resources

Self-Assessment Questions click or tap answer area to view the correct response

c. Begin immediate ocular irrigation

It is key to start irrigation of the ocular surface as soon as possible in patients with chemical exposure to the eye.

Which substance is likely to cause the most severe chemical burn in the eye?

c. Drano (lye)

Although acid can cause a severe surface burn, base substances appear to penetrate deeper in the eye structures. All exposures however, would need immediate irrigation.

What type of ocular finding would be less likely due to a chemical burn?

e. Retinal detachment

Without a history of trauma a chemical burn would not necessarily affect the retina.