What Is Corneal Abrasion?
The scratched cornea of the human eye is also known as a corneal abrasion. The cornea is a colored protective layer over the iris and the pupil. The corneal layer is important for vision, filtration of harmful rays such as intense ultraviolet rays, and protection. Corneal injury means injury to the epithelial surface of the eye (most superficial layer). Abrasion is limited to the topmost five layers of the cornea. Any dust or sand particles trapped inside the eyelid lead to scratching of the cornea. Scratching of the cornea leads to pain, heaviness, and discomfort. Eye scratching ranges from small to large abrasion. Although abrasions usually do not cause permanent vision loss or blindness, get a medical second opinion online to rule out other serious complications.
What Causes Corneal Abrasion?
- Hurting the eye with a fingernail is the most common cause. Trauma is due to external force from plants, leaves, branches, pieces of paper or cardboard, make-up brushes, or other objects.
- Blowing of the foreign particles such as deodorant fumes, perfume, dirt particles, sand, hot cigarette ash, etc. These particles are caught into eyelids, leading to scratching of the cornea.
- Accidental exposure of eyes to any harmful chemicals leads to burning injury and abrasion. House cleaning agents such as acids, phenyls, bleach, and toilet cleaners are common. Plaster dust is a strongly alkaline material that leads to scratching.
- If a person rubs his eyes intensively.
- If a person is wearing old or cracked, or expired contact lenses, improper fitting and poor hygiene of contact lenses also cause this injury.
- Bacterial infection of the eye (secondary traumatic iritis).
- If the cornea becomes dried out during surgery, it causes a corneal abrasion.
- Sometimes scratching is due to very intense bright light such as welding without eye protection. Sometimes injury occurs due to reflected sunlight from snow. Exposure to intense ultraviolet rays may lead to scratching. Wind blow also causes injury.
What Are the Precautionary Measures?
- One should keep blinking many times.
- Avoid rubbing the eyes and immediately wash the eyes with clean water or sterile solution.
- If anything is trapped inside the eyelid, do not try to remove it. The retinal doctor should remove this.
- Precautions should be taken during washing the eyes because washing may further disrupt the corneal epithelial surface several times. It may increase the scratching.
Sign and Symptoms of Corneal Scratching
Symptoms are present from a few minutes to several days.
- Presence of gritting sensation in the eye or having foreign body sensation inside the eye.
- Eye pain appears on any extraocular (eye muscles) movement such as opening and closing eyes.
- Presence of inflammatory signs such as redness and swelling.
- Frequent tearing from the eyes for a prolonged period of time.
- The eye becomes very sensitive to light.
- Abnormalities are present with vision, such as vision becoming blurred.
- The patient feels uncomfortable while driving, working, reading, and sleeping.
- One should wear sunglasses because the sun's glare may lead to pain in the injured eye.
How Is Corneal Abrasion Diagnosed?
Slit-lamp examination and fluorescein instillation are useful to confirm the exact diagnosis. Ocular CT (computed tomography) scans and MRIs (magnetic resonance imaging) are also useful for large erosions. A corneal ulcer is one of the complications. Bacterial culture is necessary before the instillation of antibiotics.
How to Treat Pain Due to Corneal Scratching?
The purpose of treatment is to reduce pain and complications. Healing takes time. Sometimes healing takes more time and also requires extensive treatment.
Treatment is initiated with the removal of contact lenses. The eyes should be washed with cold water for 15 to 20 minutes. If any foreign particles are trapped into eyelids, they will be removed immediately with the help of cotton wool.
Sometimes, the doctor uses a fine needle to remove or lift particles from the eyes. At that time, local anesthetics are used to ease the pain. A doctor can easily remove this because the eye surface is surprisingly very hard. Minor injury takes only 24 to 48 hours for healing. Deeper tissue scratching causes scarring of the cornea, and a corneal transplant treats it.
It is used for analgesic effects. Anesthetic drugs are Tetracaine and Proparacaine.
- Tetracaine - It is used in the form of solution or ointment. It works by blocking impulses to transmit through restriction of sodium permeability into the neuronal membrane. Sodium is an essential part of depolarization (activation of the cell). Its effect start within 1 to 2 minutes and remains upto 30 minutes. Dose - instill two drops in both eyes every 4 hours as required for pain relief.
- Proparacaine - It has a less irritating property. It works by providing stability to nerve cells through inhibition of initiation and transmission of impulses into cells due to the impermeability of essential ions. Its effects start within 20 to 30 seconds after application and remain for a maximum of 20 minutes. The dosage is the same as above.
Antibiotic ointments are a very useful and first line of treatment in this case. Its usage is different in contact lenses user and non-contact lenses users.
1. People Not Wearing Contact Lenses:
- Erythromycin ophthalmic ointments are used for three to five days. Dosage - four times in a day in the affected eye.
- Sulfacetamide ophthalmic. Dosage - four-time application for three to six days.
- Polymyxin Trimethoprim ophthalmic. Dosage - four times a day for five days. It is also available in solution form. One to two drops are instilled in the affected eye.
- Ciprofloxacin (0.3%) is instilled in the affected eye. One to two drops four times a day for five days.
- Ofloxacin (0.3%) is instilled in the affected eye four times a day for five days.
2. Contact Lens Wearers:
During treatment, the use of contact lenses must be avoided strongly.
- Levofloxacin (0.5%) ophthalmic solution, Moxifloxacin (0.5%) and Ofloxacin (0.3%). Dosage is one to three drops are instilled into affected eyes followed by instillation of eye drops every two hours for two days, followed by instillation of drops every four to eight hours for five days.
- Eye patch - Topical antibiotics treat Non-infected corneal abrasion. Relief from pain due to abrasion is achieved by patches also. But the use of patches has become limited nowadays because, during removal of the patch from the eye surface, it strips out the healing tissue, and abrasion aggravates. Sometimes patients find the loss of binocular vision with the use of the patch. Binocular vision means vision from both eyes. High chances of complications reduce the use of patches.
- Pain Killer Eye Drops - Diclofenac or Ketorolac eye drops are used to treat pain due to scratching. These drops come with antibiotic drops and disposable contact lenses also. These drugs maintain proper vision and help to decrease inflammation. Drops should be instilled in the affected eye. Dose - one to two drops four times a day for less than two weeks.
- Oral Pain Killers - Paracetamol or Ibuprofen 250 mg twice a day for a week is prescribed for pain relief in the eye. These drugs may reduce pain up to 90%.
- Diclofenac or Aceclofenac - These are nonsteroidal anti-inflammatory drugs and the best option in place of the patch. It is available in drops with a disposable contact lens. Diclofenac is used as Diclofenac potassium or Diclofenac sodium for pain relief. It decreases prostaglandin activity through the reduction of cytoplasm activity. Prostaglandins are an essential part of initiating pain. Dose - 50 mg every 8 or 12 hours.
- Oxycodone or Acetaminophen - It is a type of opioid agonist. It gives relief from moderate to severe pain. Dose - 2.5 mg/325 mg: 1-2 tablets every 6 hours depending upon requirement. It works by blocking the ascending pathway of pain. It causes respiratory depression, analgesia, and sedation.
- Cold compresses should be used to get relief from edema and intense pain. Warm compresses are used after two days of injury.
- Artificial Tears or lubricants are used to relieve pain, swelling, and irritation.
What Are the Complications After Abrasion?
There are many complications due to eye abrasion such as scarring, fungal ulcers, amoebic keratitis (corneal infection by amoeba), pseudomonas (one type of bacteria) infection, corneal infiltrates or ulcers (local or diffused grayish area with inflammation and edema around cornea).
Even if a person has a simple eye injury due to scratching, they should consult an eye care ophthalmologist within 24 to 48 hours.