Ophthalmologic Approach to Chemical Burns Follow-up

• In patients with severe chemical injuries, short hospitalization may be warranted to closely monitor IOP, corneal integrity, medication use, and pain control.

• Close follow-up care is mandatory in the first weeks following a severe chemical injury to assess epithelial regeneration and corneal melting, to change medications, to control inflammation and IOP, and to prevent secondary infection. Patients should be under the care of an ophthalmologist during this critical period.

• Prednisolone acetate 1% (1 gtt qid)
• Erythromycin ophthalmic ointment (4-8 times/d)
• Homatropine 5% or scopolamine 0.25% (1 gtt tid)
• Ascorbate (500 mg PO qid)
• Levobunolol hydrochloride 0.5% (1 gtt bid) or acetazolamide (500 mg PO bid) - Pressure lowering agents, such as levobunolol and acetazolamide, are only indicated if IOP is increased (>30 mm Hg).

• After completing initial irrigation and treatment, patients should be transferred to facilities that have ophthalmologists available to assume care for them.

• Education and training regarding the prevention of chemical exposures in the workplace can help prevent chemical injuries to the eye.
• Persons who may be exposed to chemicals in the workplace are advised to wear safety goggles.

Primary complications include the following:

• Conjunctival inflammation
• Corneal abrasions
• Corneal haze and edema
• Acute rise in IOP
• Corneal melting and perforations

Secondary complications include the following:

• Secondary glaucoma
• Secondary cataract
• Conjunctival scarring
• Corneal thinning and perforation
• Complete ocular surface disruption with corneal scarring and vascularization
• Corneal ulceration (sterile or infectious)
• Complete globe atrophy (phthisis bulbi): See the image below.Complete cicatrization of the corneal surface following chemical injury.

In general, the prognosis of ocular chemical injuries is directly correlated with the severity of insult to the eye and adnexal structures.

Many classification systems and revisions thereof have been aimed at classifying ocular burns in relation to their prognosis, including the following systems: Hughes, Roper-Hall, and Pfister.^[9] In essence, all systems aim to quantify the degree of corneal epithelial involvement, the degree of limbal stem cell loss, and the degree of conjunctival involvement.^[16]

Injuries can be graded from 0-5, as follows:

• Grade 0 - Minimal epithelial defect, clear corneal stroma, no limbal ischemia
• Grade 1 - Partial-complete epithelial defect, clear corneal stroma, no limbal ischemia
• Grade 2 - Partial-complete epithelial defect, mild stromal haze, none or only mild limbal ischemia
• Grade 3 - Complete epithelial defect, moderate stromal haze, less than one third of the limbus is ischemic
• Grade 4 - Complete epithelial defect, stromal haze blurring iris details, one third to two thirds of the limbus is ischemic
• Grade 5 - Complete epithelial defect, stromal opacification, greater than two thirds of the limbus is ischemic

Grades 0-2 can be expected to heal well with proper care and follow-up examinations.

The course for grades 3-5 is more tenuous and may require surgical intervention, either limbal stem cell transplantation or penetrating keratoplasty, to regenerate the corneal surface.

Higher-grade injuries are more susceptible to secondary complications.

• If the injury resulted from a preventable accident, proper safety instruction should be provided.
• If a patient is left functionally monocular from an injury, the patient should be instructed in the use of safety eyewear (eg, polycarbonate lenses).
• For excellent patient education resources, visit eMedicine's Burns Center and Eye and Vision Center. Also, see eMedicine's patient education articles Chemical Burns, Chemical Eye Burns, and Eye Injuries.