Keratitis

The first symptom of keratitis is usually redness and pain in the eye. Normally, only one eye is affected, but in some cases, the condition can affect both eyes. The symptoms often associated with keratitis include:

• Eye pain
• Eye redness
• Watery discharge
• Excessive tearing
• Difficulty in opening the eyelid due to pain or irritation
• Blurred vision
• Reduced vision
• Sensitivity to light or photophobia
• Feeling of a foreign body, like sand, in the eye

Keratitis is classified as either infectious or noninfectious. The various causes of these types are discussed below:

Infectious keratitis

Infectious keratitis is a major cause of visual impairment and blindness globally, often affecting marginalized populations. The causative agents that cause infectious keratitis are as follows:

• Bacteria: Bacterial keratitis is usually seen with improper use of contact lenses. It is mostly caused by bacteria like:
• Pseudomonas
• Staphylococcus
• Streptococcus
• Moraxella
• Nocardia
• Atypical mycobacteria
• Virus: Viral keratitis is usually associated with the following viruses:
• Adenovirus, which is one of the causes of upper respiratory tract infections
• Herpes simplex virus (HSV), the same virus that causes cold sores
• Herpes zoster virus (HZV), associated with chickenpox and shingles
• Zika virus, transmitted by Aedes aegypti mosquitoes, the same type that causes dengue
• SARS-CoV-2 virus, which causes COVID-19, is also associated with keratitis
• Parasite: Acanthamoeba keratitis is a rare but serious infection of the eye that can cause permanent vision loss or blindness. This infection is caused by a single-celled organism called Acanthamoeba. A history of exposure to soil or contaminated water is often associated with Acanthamoeba keratitis in developing countries. However, in the developed world, contact lenses have been found to mostly cause this condition.
• Fungus: Fungal keratitis is a potentially blinding infection of the cornea, which is the clear dome covering the colored part of the eye. This infection mainly occurs due to eye trauma and the use of contact lenses. However, exposure to these fungi can also occur outdoors or during agricultural work. It is caused by the following fungi:
• Aspergillus
• Fusarium
• Candida (yeast)
• Cladosporium
• Alternaria
• Curvularia
• Microsporidia
• Oomycete: Oomycete, which is morphologically similar to fungi, causes pythium keratitis.
• Helminth: Onchocercal keratitis or river blindness (sclerosing keratitis) is a parasitic corneal infection caused by motile worms. Worms do not usually cause blindness by themselves; however, as they die naturally or after treatment, they cause inflammation and corneal opacification. Repeated episodes can result in complete opacification of the cornea and lead to blindness. This condition is rarely seen in developed countries but is very common in developing countries in Africa, Asia, Latin America, and Australia.

Noninfectious keratitis

The following causes or conditions may lead to noninfectious keratitis:

• Local causes: The following can cause irritation in the sulcus subtarsalis (a groove in the inner surface of the eyelid near the eyelid margin) and lead to keratitis:
• Foreign body
• Trichiasis, which is anatomic misalignment of eyelashes
• Entropion, a condition in which the eyelid folds inwards
• Distichiasis, a rare condition of having two rows of eyelashes
• Giant papillae, where the inside of the eyelid, which is usually very smooth, becomes red, swollen, and irritated, often seen in people who wear soft contact lenses
• Collagen vascular diseases: Diseases such as rheumatoid arthritis, granulomatosis with polyangiitis, polyarteritis nodosa, relapsing polychondritis, and systemic lupus erythematosus can cause peripheral ulcerative keratitis.
• Damage to the ophthalmic division of the trigeminal nerve: Surgeries involving the cornea, such as cataract surgery, orbital surgery, laser eye surgery to correct vision, corneal transplants, and surgery or tumors involving the trigeminal nerve can potentially damage the ophthalmic division of the trigeminal nerve and result in neurotrophic keratitis.
• Xerophthalmia: Vitamin A deficiency causes abnormal dryness of the conjunctiva and cornea of the eye, leading to subsequent necrosis and keratitis.

Factors that may increase your risk of keratitis include:

• Contact lenses: Wearing contact lenses increases the risk of both infectious and noninfectious keratitis, especially in the following cases:
  • Wearing lenses while sleeping
  • Using extended-wear contact lenses
  • Not disinfecting lenses properly
  • Not cleaning the case or container of lenses
  • Using visibly contaminated lens solution to clean lenses
  • Not discarding or replacing the used lens solution while storing contact lenses
  • Adding fresh solution to existing used solution in the case instead of using only fresh solution while storing contact lenses
  • Storing or rinsing lenses with water
  • Swimming or bathing while wearing lenses
  • Sharing non-corrective lenses used for cosmetic reasons
• Eye injury: Previous eye injuries, such as scratches or tears, may increase vulnerability to developing keratitis.
• Weakened immune system: A compromised immune system due to certain diseases or medications can increase susceptibility to keratitis.
• Corticosteroids: Overuse or long-term use of corticosteroid eye drops to treat any eye disorder can increase the risk of developing infectious keratitis or worsen existing keratitis.
• Exposure to intense light: Exposure to natural sunlight, such as reflections from snow, water, ice, or sand, or staring at the sun without proper eye protection can increase the risk of keratitis. Photokeratitis can also be triggered by artificial sources of ultraviolet (UV) light, such as tanning beds and lamps.

In case of any suspected symptoms of keratitis, a doctor should be consulted immediately to ensure proper treatment is administered before any further complications arise. The doctor will examine the eyes and discuss the symptoms being experienced. Diagnosing keratitis typically involves the following:

• Eye exam: If your eye is sealed shut from an infection, the doctor will assist in opening it to conduct a full examination and check for visual acuity.
• Slit-lamp exam: This standard diagnostic procedure, also known as biomicroscopy, is usually part of a comprehensive eye exam. It provides a bright source of light and magnification to detect the character and extent of keratitis, as well as its effects on other structures of the eye.
• Penlight exam: A penlight is used to check the pupil for any unusual changes. The doctor may apply a stain to the surface of the eye to identify the extent of surface irregularities and ulcers of the cornea.
• Laboratory tests: Doctors can take a sample of tears or a small scraping from the cornea for laboratory analysis to determine the cause of keratitis. This test is also helpful in treatment planning.

While keratitis can happen to anyone, there are a few steps that help to prevent its occurrence.

1. Do's and Don'ts While Using Contact Lenses

• Follow the advice of your eye doctor about how to wear, replace, store, and clean contact lenses.
• Wash, rinse, and dry your hands thoroughly before handling your contacts.
• Replace your contact lens case every three to six months.
• Use only sterile lens solutions that are made specifically for contact lens care.
• Discard the used solution in the contact lens case each time you disinfect your lenses.
• Gently rub the lenses during cleaning. Avoid rough handling or scratching of lenses.
• Avoid sleeping in contact lenses.
• Contact lenses should not be worn while bathing or swimming.
• Do not share colored or cosmetic contact lenses.
• Visit your eye doctor for regular checkups.

2. Tips to Protect Your Eyes

Keratitis can also affect people who do not wear contact lenses. Eyes can be protected from damage by:

• Wearing sunglasses when exposed to intense sunlight.
• Wearing protective eyewear while doing agricultural work.
• Being aware of allergens and avoiding them, if possible.
• Consuming a diet rich in Vitamin A.

3. Prevent Viral Keratitis

Some forms of viral keratitis can't be completely prevented. But the following steps can help to reduce the risk of viral keratitis:

• Avoid touching your eyes, your eyelids, and the skin around your eyes with dirty hands.
• Wash your hands frequently with antiseptic soap solution to prevent viral outbreaks.
• Only use eye drops that are prescribed by the doctor.

Infectious Keratitis

Infectious keratitis is one of the major causes of avoidable blindness. Therefore, appropriate and timely management could reduce the incidence of corneal damage and loss of vision.

• Bacterial Keratitis: Antibiotic therapy should be promptly started as bacterial keratitis is an eye emergency due to its rapid progression and potential complications. Combination therapy of antibiotics such as cefazolin and tobramycin or gentamicin can be given, with the dose dependent on the severity of the infection. For keratitis caused by methicillin-resistant Staphylococcus aureus (MRSA), drugs like topical vancomycin and topical linezolid can also be given. Aminoglycoside antibiotics can be used along with fortified drops of gentamicin and tobramycin. Cephalosporin drugs are also used with fortified drops of cefazolin. Antibiotics like amikacin are useful for treating infections due to gram-negative organisms resistant to tobramycin and gentamicin.
• Protozoal Keratitis: Early diagnosis is essential for effective treatment of Acanthamoeba. The infection can be difficult to treat due to the resilient nature of the cyst form of Acanthamoeba. The treatment usually includes a topical cationic antiseptic agent such as biguanides and pentamidine. Polyhexamethylene biguanide (PHMB) and chlorhexidine are the commonly used biguanides. In some cases, the addition of levofloxacin to the antiprotozoal treatment might augment treatment of resistant cases.
• Viral Keratitis: Topical antiviral acyclovir is the mainstay of treatment for viral keratitis. However, steroids can also be recommended in some cases. For herpes simplex virus infections, a topical steroid is usually prescribed. Herpes zoster keratitis is typically treated with oral acyclovir, which is also given to prevent recurrence of infection.
• Fungal Keratitis: Depending upon the type of fungus, the following treatment options are recommended: Amphotericin B is active against Aspergillus and Candida species and is commonly administered as a topical solution. Natamycin is the first-line treatment in fungal keratitis and is considered to be the most effective medication against Fusarium and Aspergillus species. Fluconazole is available in oral, topical, and intravenous preparations and is effective in patients who do not respond to natamycin or miconazole in the treatment of Candida keratitis. Ketoconazole is available in oral and topical form and is known to have good in-vitro activity against Aspergillus, Candida, and Curvularia species. Very rarely, some cases of infectious keratitis are resistant to medication and lead to permanent eye damage. For this, your doctor may recommend a corneal transplant.

Non-Infectious Keratitis

Treatment of noninfectious keratitis varies depending on the severity.

• Local Causes: Patients with keratitis related to trichiatic lashes, entropion, or distichiasis need early correction. The treatment for these includes electrolysis of eyelash hair root follicle, lid everting procedures, or lid splitting procedures, respectively. Keratitis associated with giant papillae is managed with topical steroids along with topical cyclosporine and lubricants.
• Systemic Causes:
  • Rheumatoid Arthritis (RA): The treatment involves topical and oral steroids and methotrexate.
  • Granulomatosis with Polyangiitis (GPA): Cyclophosphamide is the drug of choice along with topical and oral steroids.

Early treatment can facilitate a quick recovery from keratitis. However, delayed treatment may lead to serious complications, including:

• Corneal scars: Trauma, infections, or degenerative conditions can cause corneal scars, resulting in loss or reduction of vision.
• Long-term inflammation: Keratitis is an inflammatory disorder of the cornea. Symptoms and complications vary depending on the layer of the cornea affected. Inflammation in the stroma (middle layer of the cornea) can lead to permanent scarring. In some cases, the scars may fade enough for vision to return to normal. However, inflammation in the endothelium (the innermost layer of the cornea) may cause long-term vision impairment depending on the extent of the damage.
• Corneal ulcers: Chronic corneal inflammation and scarring can lead to recurrent viral infections in the cornea, resulting in open sores (corneal ulcers) that may predispose individuals to temporary or permanent vision reduction.
• Recurring infections: Untreated keratitis can result in recurring infections. Keratitis may or may not be associated with an infection.
• Glaucoma: Rarely, keratitis can lead to glaucoma, a condition in which the eye’s optic nerve is damaged with or without elevated intraocular pressure, potentially resulting in gradual vision loss.
• Loss of vision: Most cases of keratitis can be treated without resulting in vision loss. However, severe infections may lead to serious complications that can permanently damage vision.

Homeopathic treatment for keratitis

Homeopathic medicines play a supportive role in keratitis and can be used alongside conventional treatment for effective relief from symptoms such as pain, burning, and discharge. Here are a few homeopathic medicines for keratitis:

• Belladonna: This natural medicine is prepared from the plant known as deadly nightshade. Belladonna is frequently used for eye troubles, including eye redness and congestion.
• Apis mellifica: This natural remedy is effective for treating pain in the eyes due to keratitis. The key features for using Apis mellifica include pain that may be stinging, tearing, lancinating, or shooting in nature.
• Euphrasia: This homeopathic medicine for keratitis is prepared from the plant Euphrasia Officinalis, also known as eye-bright. Euphrasia is beneficial in cases of keratitis characterized by excessive tear secretion and intense photophobia.
• Pulsatilla: A homeopathic remedy for eye discharges in keratitis, prepared from the fresh plant Pulsatilla nigricans. It is used for symptoms such as eye discharge, burning and itchy eyes, and sticky eyelids in the morning.

With proper diagnosis and appropriate treatment including follow-up care, keratitis can usually be managed without causing permanent visual disturbances. A continuous evaluation of the eyes by a general practitioner is advised if you have eye-related signs or symptoms that concern you. Depending on the type and severity of your symptoms, your doctor may refer you to an eye specialist (ophthalmologist).

In case a person is using contact lenses and the eyes become red and inflamed, promptly remove your contact lenses. Avoid touching or rubbing your eyes, as this can often lead to infection. Always lubricate your eyes with eye drops, as this helps ease the symptoms of keratitis.

Be sure to follow your healthcare provider's advice about:

• Wearing contact lenses
• Cleaning contact lenses
• Storing contact lenses

Always wash your hands before handling contact lenses, and remove them before sleeping or swimming.

In case of a viral infection, make sure to wash your hands thoroughly with an antiseptic before touching your eyes.

Contact your eye doctor immediately if you experience:

• Redness
• Eye pain
• Blurry vision