Keratitis is the inflammation of the cornea which is the clear outer layer of the eye that focuses light. The severity of keratitis may range from mild to severe and can be associated with inflammation of other regions of the eye as well. It may also involve one eye (unilateral) or both eyes (bilateral).
Keratitis is caused by either infectious agents or non-infectious causes. Infectious diseases are mainly caused by microbes like bacteria, fungi, viruses, and parasites. The noninfectious keratitis is majorly caused by local factors irritating the eye, or other systemic diseases affecting the eye.
Some of the common symptoms of keratitis are eye irritation and pain, eye discharge, sensitivity to light, blurred vision or partial blindness, and red eyes.
Keratitis is typically easy to treat and resolves quickly. However, if the infection spreads beyond the surface of your cornea, it may leave scars that impair your eyesight or possibly cause loss of vision. Thus, appropriate and timely management is very important.
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 the eyes. The symptoms often associated with keratitis are:
Eye pain
Eye redness
Watery discharge
Excessive tearing
Difficulty in opening the eyelid because of pain or irritation
Blurred vision
Reduced vision
Sensitivity to light or photophobia
Feeling of a foreign body like sand in eye
Keratitis is classified as either infectious or noninfectious. The various causes of these types are discussed below:
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:
2. 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) is the same virus that causes cold sores
Herpes zoster virus (HZV) which is associated with chickenpox and shingles
Zika virus which is transmitted by Aedes aegyptus mosquitoes, the same type that causes dengue
SARS-CoV-2 virus, which causes COVID-19, is also associated with keratitis
The following causes or conditions may lead to noninfectious keratitis:
1. 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 which is a condition in which the eyelid folds inwards
Distichiasis is a rare condition of having two rows of eyelashes
Giant papillae in which the inside of the eyelid which is usually very smooth gets red, swollen, and irritated. It is usually seen in people who wear soft contact lenses.
2. Collagen vascular diseases: Diseases such as rheumatoid arthritis, granulomatosis with polyangiitis, polyarteritis nodosa, relapsing polychondritis, systemic lupus erythematosus can cause peripheral ulcerative keratitis.
3. Damage to the ophthalmic division of the trigeminal nerve: Surgeries involving the cornea like cataract surgery, orbital surgery, laser eye surgery to correct vision, corneal transplants and surgery or tumor involving the trigeminal nerve can potentially damage the ophthalmic division of the trigeminal nerve and result in Neurotrophic keratitis.
4. Xerophthalmia: Vitamin A deficiency causes abnormal dryness of the conjunctiva and cornea of the eye with subsequent necrosis resulting in keratitis.
Factors that may increase your risk of keratitis include:
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 which are used for cosmetic reasons
Eye injuries such as a scratch, tear or injury in the past, you may be more vulnerable to developing keratitis.
Compromised immune system due to some disease or medications can increase the susceptibility to keratitis.
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 natural sunlight in the form of reflection of sunlight from snow, water, ice or sand or by staring at the sun without special eye protection can increase the risk of keratitis. Photokeratitis can also be triggered by manmade sources of ultraviolet (UV) light like tanning beds and tanning lamps.
In case of any suspected symptoms of keratitis, a doctor should be consulted immediately so that proper treatment is given before any further complications arise.
The doctor will examine the eyes and discuss the symptoms that are being experienced.
Diagnosing keratitis typically involves the following:
If your eye is sealed shut from an infection, the doctor will help you open it to conduct a full examination of eyes and check for visual acuity.
The slit lamp exam is a standard diagnostic procedure, which is also known as biomicroscopy. It is usually a 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 the effect it may have on other structures of the eye.
A penlight is used for checking 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.
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 for keratitis.
While keratitis can happen to anyone, there are a few steps that help to prevent its occurrence.
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 coloured or cosmetic contact lenses.
Visit your eye doctor for regular checkups.
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.
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.
The diagnosis of keratitis is done by an ophthalmologist who is a physician who specializes in diseases and surgery of the eye. The ophthalmologist will record comprehensive history and perform physical examination of eyes. If needed, some lab tests or cultures can also be advised.
If you are facing any eye-related problems, consult our medical professionals.
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.
1. 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. The dose is 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.
2. 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, addition of levofloxacin to the antiprotozoal treatment might augment treatment of resistant cases.
3. Viral keratitis:Topical antiviral acyclovir is the mainstay of treatment for viral keratitis. Howover, steroids can also be recommended in some cases.
For herpes simplex virus infections, a topical steroid is usually prescribed.
Herpes zoster keratitis is usually treated with oral acyclovir. It is also given to prevent recurrence of infection.
4. Fungal keratitis: Depending upon the type of the fungus, the following treatment options are recommended:
Amphotericin B is active against Aspergillus and Candida species, and commonly administered as a topical solution.
Natamycin is the first line treatment in fungal keratitis. It is considered to be the most effective medication against Fusarium and Aspergillus species.
Fluconazole is available in oral, topical, and intravenous preparations. This drug is found efficacious in patients who do not respond to natamycin or miconazole in the treatment of Candida keratitis.
Ketoconazole is available in oral and topical form. It 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 having a corneal transplant.
Treatment of noninfectious keratitis varies depending on the severity.
1. Local causes
Patients with keratitis related to trichiatic lashes, entropion, or distichiasis need early correction. The treatment for these include 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.
2. 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.
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 worry 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 eyes become red and inflamed, promptly remove your contact lenses. Avoid touching eyes and rubbing eyes as it can often lead to infection. Always lubricate eyes with eye drops as it helps ease the symptoms of keratitis.
Be sure to follow your healthcare provider's advice about wearing, cleaning, and storing your contact lenses.
Always wash 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, or blurry vision.
Homeopathic medicines play a supportive role in keratitis and can be used along with conventional treatment for effective relief from symptoms like pain, burning, and discharge. Here are a few homeopathic medicines for keratitis:
Belladonna: This is a natural medicine which is prepared from the plant called deadly nightshade. Belladonna is the most frequently used remedy in eye troubles like eye redness and congestion.
Apis mellifica: It is a natural remedy for treating pain in the eyes due to keratitis. The key features for using Apis mellifica include pain which may be stinging, tearing, lancinating, or shooting in nature.
Euphrasia: This is a homeopathic medicine for keratitis prepared from the plant Euphrasia Officinalis, also known as eye-bright. Euphrasia is useful in the case of keratitis where there is excessive secretion of tears and intense photophobia.
Pulsatilla: A homeopathic cure for eye discharges in keratitis prepared from the fresh plant Pulsatilla nigricans. It is used in case of eye discharge, burning and itchy eyes, and sticky eyelids in the morning.
Early treatment can make you recover quickly from keratitis. However, delayed treatment may lead to serious complications including:
Trauma, infections, or degenerative conditions can cause corneal scars which can lead to loss or reduction in vision.
Keratitis is an inflammatory disorder of the cornea. Depending on the layer of cornea affected, the symptoms and complications are different. Inflammation in the stroma (middle layer of the cornea), can lead to permanent scarring. In some cases, the scars fade enough for the vision to return to normal. However, inflammation in the endothelium, or the innermost layer of the cornea, may cause long-term vision impairment depending on the extent of damage.
Chronic corneal inflammation and scarring can lead to recurrent viral infections in your cornea. This often leads to open sores on the cornea (corneal ulcers) and can predispose to temporary or permanent reduction of vision.
When keratitis is not treated for a longer period of time it leads to recurring infections. Keratitis may or may not be associated with an infection.
Rarely keratitis can lead to glaucoma, a condition when the eye’s optic nerve is damaged with or without raised intraocular pressure. This can lead to gradual vision loss.
Most cases of keratitis can be treated without loss of vision. However, some cases of severe infection can lead to serious complications that may permanently damage vision.
