Keratitis - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Indeed, our eyes are the window to our souls. Without good vision, a person's life would stumble. The eyes are made of layers like the conjunctiva, cornea, iris, sclera, pupil, lens, and retina. All these layers are prone to injuries and infections like glaucoma, cataract, retinopathy, conjunctivitis, etc.

The transparent frontal layer of the eye with a dome structure is called the cornea. The cornea plays an essential role in protecting the inner contents of the eye, focusing light on the retina to form an image, and the eye's refractive power is maintained. The inflammation of this corneal layer is called keratitis. Keratitis may or may not be of infectious origin. This article will contain the cause, symptoms, and management of keratitis.

What Are the Causes of Keratitis?

The causes are grouped into two categories - infectious keratitis and non-infectious keratitis.

Infectious Keratitis

• Bacteria- Staphylococcus aureus and Pseudomonas aeruginosa cause bacterial keratitis, especially in those who wear contact lenses for a longer time.

• Fungi- Aspergillus and Candida are found to cause keratitis. Same as bacterial keratitis, this also affects contact lens wearers predominantly.

• Parasites- Acanthamoeba is the most common parasite that causes keratitis. It is mainly picked up from swimming pools or lakes or by using contaminated water to wash the contact lenses.

• Virus- Herpes simplex virus causes conjunctivitis progressing to keratitis.

Non-infectious Keratitis

• Injury- A sharp object can injure the corneal layer. This injury might make way for the microbes to enter the site causing infectious keratitis.

• Contact Lenses- Wearing contact lenses for a long time can cause keratitis.

• Overexposure to sunlight can cause photokeratitis.

• A weak immune system can trigger keratitis.

• Dry eyes.

• Bell's palsy

What Are the Symptoms of Keratitis?

• Redness of the eye.

• Swelling of the eye.

• Pain and irritation.

• Difficulty in opening the eyelid.

• Excessive tearing of the eye.

• Discharge from the eye.

• Sensitive to light.

• Blurred vision.

What Are the Risk Factors of Keratitis?

• Those who wear contact lenses are prone to acquiring keratitis. Wearing it for a longer time, wearing it while swimming, and not cleaning it properly are the causes.

• Using corticosteroids, eye drops can escalate existing keratitis or cause new inflammation.

• If a person has an eye injury, she/he is more prone to develop keratitis.

• A weakened immune system is prone to keratitis.

What Are the Possible Complications of Keratitis?

• Permanent blindness.

• Open wound in the cornea (corneal ulcers).

• Chronic inflammation of the cornea leads to corneal scarring causing vision problems.

How to Diagnose Keratitis?

Examining the eyes entirely is very crucial in planning the treatment.

• Penlight Test- Using a penlight torch, the dilation and movement of pupils are assessed. The doctor might even stain the eye with a dye to study the irregularities of the corneal layer.

• Slit Lamp Test- For this test, the patient will be made to sit across from the doctor. A microscope attached to a slit lamp will be used to focus and study the layers of the eye. The extent and characteristics of keratitis will be examined.

• Laboratory Tests- The teardrops will be sent for lab tests to diagnose the causative factor to prepare a proper treatment plan.

How to Manage Keratitis?

Non-infectious Keratitis-

Management of keratitis highly depends on the severity and symptoms of keratitis. In most cases, conservative treatment is sufficient.

• If the symptoms are mild and only a scratchy sensation is present, artificial tear drops or eye drops are the only treatment of choice.

• If the corneal ulcer is associated with immense pain and discomfort, a 24 hours eye patch is prescribed. Topical medications are also prescribed.

Infectious Keratitis-

• Bacterial Keratitis- Bacterial keratitis must be treated immediately due to the bacteria's ability to progress rapidly and cause corneal damage. For mild bacterial keratitis, antibacterial eye drops are prescribed and are found to be effective in the majority of cases. In severe cases, oral antibiotics are found to do good.

• Fungal Keratitis- Same as bacterial keratitis, mild cases of fungal keratitis can be treated with antifungal eye drops, and severe cases are treated with topical medications. Nintamycin is the choice of treatment.

Debriding a load of infection from the surface will promote better drug penetration.

Drops are prescribed to use every half an hour to one hour and taper the usage as the conditions improve.

• Parasite Caused Keratitis (Acanthamoeba Keratitis)- Acanthamoeba keratitis is not easy to diagnose and treat. Chlorhexidine and Polyhexamethylene are the choices of drugs to treat acanthamoeba keratitis. Long-term use of medications is advised to prevent relapses.

• Viral Keratitis- Acyclovir taken twice daily is the choice of drug to treat viral keratitis. Systemic corticosteroids are prescribed in case of immense pain and swelling.

When Does the Condition Not Heal?

If keratitis does not heal even after the condition is adequately treated for two to three weeks, it is referred to as a non-healing ulcer. The reasons for this include,

• Inadequate Treatment - Improper use of medication, dosage, and frequency could be the cause.

• Drug Resistance - The whole world is reporting increased resistance of bacteria to antibacterial drugs.

• Toxicity - Continuous aggressive treatment will lead to toxicity even after the condition responds well.

How to Prevent Keratitis?

Prevention of keratitis includes proper use of contact lenses and keeping safe from exposure to infectious agents.

Contact Lens

• Use contact lenses only when required, and avoid wearing them for a long time.

• Wash hands thoroughly before handling the lenses.

• Use proper disinfectants to clean lenses.

• Replace the contact lenses every three to six months.

• Do not use contact lenses in the swimming pool.

• Replace the solution in the contact lens box every time. Do not use the old solution again.

Preventing the Viral Keratitis

Exposure to viral load cannot be stopped. But,

• If you suspect a blister to be herpes-induced, clean your hands thoroughly before touching the eyes and surrounding areas.

• Use only the eye drops prescribed by the doctor.

Conclusion:

Keratitis needs immediate care, especially in the case of bacterial keratitis. Medical advancements are promising great healing. It is always good to prevent a condition from happening. Proper handling of the contact lens and following a hygienic lifestyle will avoid keratitis to a greater extent.