Article

CLINICAL: CORNEA

SCRATCHING THE SURFACE

HOW TO IDENTIFY AND MANAGE CORNEAL ABRASIONS

ONE OF the most common reasons for optometric urgent care is corneal abrasions. That said, differentiating a corneal abrasion from another condition, such as infectious keratitis, can sometimes be challenging. Therefore, it is important to understand how to differentiate these conditions to ensure the urgent care patient receives the correct treatment.

Here, I discuss the etiology, symptoms, clinical signs and management of corneal abrasions.

ETIOLOGY

Corneal abrasions can occur because of many reasons, such as an injury from sports, rough play, foreign matter, such as dirt, sand and sawdust, poorly maintained and improperly fitting contact lenses, forceful eye rubbing, ocular bacterial infection and lagophthalmos. The latter causes chronic dry eye symptoms, which may weaken epithelial cells and, thus, lead to corneal abrasions and frequent corneal erosions.

SYMPTOMS

Common symptoms include:

  • Acute eye pain (mild or severe, depending on the extent of the abrasion)
  • Blurry vision
  • Epiphora
  • Foreign-body sensation
  • Photophobia

CLINICAL SIGNS

Common red flags for corneal abrasion:

  • Conjunctival hyperemia
  • Corneal edema
  • Epithelial defects (visualized with NaFl staining)
  • Iritis
  • Reduced VA

ICD 10

Injury of conjunctiva and corneal abrasion without foreign body, unspecified eye ......................S05.00xA

DIAGNOSIS/MANAGEMENT

The key to a definitive diagnosis is to conduct a thorough case history. Other conditions that might mimic those of a corneal abrasion and, therefore, should be included in your differential diagnosis:

  • Acute angle closure. Decreased vision, nausea/vomiting, ocular pain and photophobia.
  • Anterior basement membrane corneal dystrophy. Blurred and fluctuating vision, foreign-body sensation, ocular pain, photophobia and, when abrasions occur, epiphora.
  • Contact lens overwear. Corneal edema, decreased vision, hyperemia, ocular pain and photophobia.
  • Corneal foreign body. Blurred vision, epiphora, foreign-body sensation, hyperemia and ocular pain.
  • Herpes simplex virus (HSV). Dendrites, which appear like an epithelial defect early on with irregular epithelial staining, ocular pain and photophobia. Ask patients in whom you’re not sure whether you’re dealing with corneal edema or HSV, “Have you had eye infections or cold sores?” A “yes,” indicates you’re potentially dealing with HSV.
  • Infection. Decreased vision, hyperemia, hypopyon, keratitis, irregular epithelial surface, iritis and ocular pain.
  • Lid issues. Internal hordeolum not visible will cause ocular pain.
  • Staphylococcus marginal/limbal keratitis. Foreign-body sensation, hyperemia, keratitis, ocular pain and photophobia.

Management for corneal abrasions consists of:

  • Amniotic membranes. This is for chronic and/or severe cases. Cryopreserved (Prokera, Bio-Tissue) amniotic tissue can help facilitate healing by regenerating corneal tissue and nerves. These tissues have anti-inflammatory and pro-healing properties to prevent corneal scar formation and decrease the chance of developing recurrent corneal abrasions down the road. Amniotic membranes are typically left in the eye for one to five days, or until the epithelial defect has healed, and, thus, the cornea is intact.
  • Antibiotics. Topical antibiotics, such as fourth-generation fluoroquinolones, should be used as first-line therapy for any corneal abrasion. Corneal abrasions and epithelial defects decrease the structural integrity of the cornea and increase the risk of pathogens entering the damaged epithelial tight junctions. Prophylactic treatment decreases the risk of infection, and you need to start therapy as soon as possible. Topical antibiotics are typically dosed t.i.d. to q.i.d. for seven days. They can also help decrease MMP-9 production. MMP-9s facilitate and promote epithelial cell damage. They are proteolytic enzymes released by stressed and desiccating epithelial cells, causing tight junction damage at the cellular level. (All contact lens wearers who present with pain should be followed for infectious keratitis. It’s prudent to prescribe topical antibiotics in these patients, and using topical steroids alone are contraindicated.)
  • Artificial tears. Artificial tears, gels and lubricating ointments help lubricate the cornea, offering some comfort and pain relief to all patients, regardless of the stage of the disease. They also help to accelerate the healing process by providing a smooth surface with reduced friction, further decreasing any additional damage.
  • Bandage contact lenses. This treatment can help patients who have mild to severe abrasions. Bandage contact lenses offer a few therapeutic advantages. By placing a contact lens on the eye, you provide a physical barrier that can prevent infectious bugs from entering the corneal tissue. However, the main reason to use this approach is to offer immediate pain control to patients. Typically, a bandage contact lens is left in the eye until the epithelial defect and abrasion have re-epithelized, and there is no longer a defect visible with NaFl stain.
  • Cycloplegics. This treatment can help patients who have moderate to severe abrasions. Cycloplegics, such as atropine sulfate 1%, decrease pain by reducing ciliary body spasm. They are typically dosed b.i.d. to t.i.d. for two to three days or longer, as needed.
  • NSAIDs. This treatment can help patients who have moderate to severe abrasions. Topical NSAIDs offer additional analgesic relief for patients. Most topical NSAIDs are dosed q.d. to b.i.d. for one to seven days.
  • Oral acetaminophen. This treatment can help patients who have mild to severe abrasions. OTC commercial acetaminophen can offer good analgesic therapy when patients are having pain during the early stages of a corneal abrasion.

Many of these treatments can be used concomitantly.

In terms of future treatments, AM-UC drops (Regenesol, Bio-Tissue) are in the pipeline for the treatment of corneal abrasions. These are umbilical cord amniotic membrane drops that are being studied to reduce pain and quicken the re-epithelialization process after corneal surgeries, such as PRK, PTK and epi-off cross-linking. They are administered b.i.d., and promise to offer a speedy recovery.

Staining on a cornea shows severe HSV keratitis.
Courtesy of Josh Johnston, O.D., F.A.A.O.

IDENTIFYING THE CULPRIT

Delineating between what appears to be a simple corneal abrasion vs. a more severe issue is a must for the proper management of these patients. Let’s make sure our urgent care patients receive the correct diagnosis, so that we can prescribe the most appropriate treatment and, thus, return them to pristine ocular health. OM