Chemical Burn

Chemical Burn
SYMPTOMS Eye pain, Eye discomfort, Photophobia, Foreign body sensation, Difficulty opening the eye, Excessive tearing, Decrease in vision
SIGNS Conjunctival injection, Conjunctival chemosis, Superficial punctate keratitis/Punctate epithelial erosions, Corneal clouding, Corneal neovascularization, Corneal pannus, Corneal scars, Corneal edema, Symblepharon, Entropion, Ectropion, Trichiasis
A white, blanched eye is an indication of vascular damage which will eventually lead to tissue necrosis
Chemical burns that affect the limbus will cause stem cell damage, delayed healing, conjunctivalization of the cornea, corneal neovascularization, and corneal opacification
Chemical burns can also cause an increase in IOP and secondary glaucoma
Stages of Chemical Burns: Newer staging of Chemical Burns:
Grade I: Clear cornea (Presence of epithelial damage only) and no evidence of limbal ischemia Grade I: No clock hours of limbal involvement and no bulbar conjunctival involvement
Grade II: Hazy cornea (Iris detail still visible) and < 1/3 limbal ischemia Grade II: < 3 clock hours of limbal involvement and < 30% of bulbar conjunctival involvement
Grade III: Total loss of epithelium with hazy cornea (Iris detail hazy) and 1/3-1/2 limbal ischemia Grade III: 3-6 clock hours of limbal involvement and 30-50% of bulbar conjunctival involvement
Grade IV: Opaque cornea and >1/2 limbal ischemia Grade V: 10-11 clock hours of limbal involvement and 76-99% of bulbar conjunctival involvement
Grade IV: 7-9 clock hours of limbal involvement and 51-75% of bulbar conjunctival involvement
Grade VI: 12 clock hours of limbal involvement and 100% bulbar conjunctival involvement
Grade I and Grade II chemical burns have a good prognosis | Grade III and Grade IV chemical burns have a poor prognosis Grade I chemical burns have a very good prognosis | Grade II and III chemical burns have a good prognosis | Grade IV chemical burns have a good to guarded prognosis | Grade V chemical burns have a guarded to poor prognosis | Grade VI chemical burns have a very poor prognosis
WORK-UP Pupils | Full eye exam with dilation | NaFl staining | Lid eversion | pH testing
TREATMENT When chemical gets into eye: Irrigate the eye for at least 15-30 minutes (the longer the better) using an eye wash station, saline, or a Morgan lens. Continue to irrigate the eye until the pH returns to 7.2-7.4. Lid eversion may need to be done to remove any particles
Day 1-21: Begin a topical antibiotic such as Polytrim 1gtt QID or Moxeza 1gtt BID Begin topical steroid (Pred Forte) regardless of whether there is an epithelial defect or not 1gtt Q2H for at least 7 days (If there is a non-healing epithelial defect, the steroid should be tapered after 10-14 days/If there is no epithelial defect, the topical steroid can be continued) Use preservative free artificial tears Q1H Begin Doxycycline 100mg PO 1 tab bid (Decrease in MMPs which are linked with corneal melting) and Vitamin C 1g PO qd If IOP is elevated, use Combigan 1gtt bid (Should not use prostaglandins, pilocarpine, or CAIs) Consider an amniotic membrane Consider autologous serum 20-40% concentration
Day 22 and on: Refer to ophthalmology if patient needs treatment for symblepharon, lid reconstruction, or a corneal transplant
Grade I and II (Old classification) and Grade I-III (New classification) can/should be managed and treated by ODs
Grade III and IV (Old classification) and Grade IV-VI (New classification) should be referred to ophthalmology/hospital setting as these patients need to be watched daily and carry a poorer prognosis
FOLLOW-UP Monitor every 24-48 hours for the first 21 days or until it is healed
ADDITIONAL LAB | TESTS None
ETIOLOGY Occurs when a chemical gets into the eye There are 2 main types of chemicals:
(1) ACID: Rarely leads to corneal penetration. Damage localized to areas of contact (Surface proteins coagulate which provides a protective barrier against further penetration) (2) ALKALI: Rapid corneal penetration (Increase in pH breaks down fatty acids in cell membranes which leads to breakdown of intercellular links, epithelial cell apoptosis, and destruction of keratocytes in the stroma)
Types of Acid: Hydrofluoric acid | Sulfuric acid Types of Acid: Hydrofluoric acid | Sulfuric acid
DIFFERENTIAL DX Conjunctival foreign body, Corneal foreign body, Conjunctivitis, Corneal ulcer
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Posted in Ocular Conditions, Trauma