Interstitial Keratitis: Everything You Need to Know
Interstitial Keratitis (IK) is a type of non-ulcerative inflammation of the corneal stroma.
Stroma is the thickest layer of the cornea, composed of collagen fibrils.
These fibrils allow the clear transmission of light.
An inflammation of this stroma can lead to vision loss if not treated properly.
Interstitial keratitis is responsible for 10% of preventable blindness in the world’s least-developed nations.
This article overviews the symptoms, causes, and treatment available for Interstitial Keratitis and diagnostic procedures.
Interstitial Keratitis Symptoms
Interstitial keratitis can lead to decreased vision based on the degree and the location of the involvement.
Following are some commonly observed signs and symptoms of the condition.
- Photophobia
- Eye pain
- Excessive tearing
- Conjunctival infection
- Ground-glass appearance of the cornea
- Corneal haze
The injury begins as patches of inflammation of the stroma.
This leads to cloudiness in the lens.
New blood vessels start to grow in from the edge of the cornea (neovascularization), causing red-orange patches.
Choroiditis and anterior uveitis are also indications of syphilitic interstitial keratitis.
Stages
The progression of Interstitial keratitis can be divided into three stages.
Initial progressive stage
This stage is characterized by acute inflammation of the cornea, causing pain, redness, tearing, and sensitivity to light.
The inflammation could be due to several factors, which will be discussed in the next section.
During this stage, the cornea may appear hazy or cloudy due to inflammation, and vision may be blurred or distorted.
Florid stage
In the second stage, you can observe the formation of scar tissue within the cornea.
This scar tissue can cause the cornea to become opaque, which can lead to further vision loss.
In some cases, blood vessels may also grow into the cornea.
These blood vessels can cause the cornea to appear red or pink in color.
It can also contribute to further scarring and vision loss.
Stage of regression
Resolution of the inflammation and scarring in the cornea starts in this stage.
This stage might be triggered naturally over time or might result from treatment.
The cornea may become clearer during this stage, and blood vessels may recede from the affected area.
However, even after the inflammation and scarring have resolved, there may be lasting damage to the cornea that can cause permanent vision loss.
Causes
Interstitial keratitis could be infectious or non-infectious depending upon the factor causing it.
Viral, bacterial, mycobacterial, and parasitic IK is infectious, while others are non-infectious.
Infectious Interstitial keratitis can be caused due to pathogens that cause Syphilis, Tuberculosis, Herpes simplex virus (HSV), Lyme disease, etc.
The non-infectious IK could be due to an allergic reaction or auto-immune diseases like arthritis or lupus.
The most common causes of IK in the United States of America are Herpes Simplex Virus and Syphilis.
Diagnosis
Diagnosis of IK is based on a combination of clinical examination and laboratory testing.
Your doctor might perform one or more of the following tests to examine the cause and severity of your condition.
- Slit lamp test for corneal haze and other ocular and corneal abnormalities
- Serological tests for the presence of infectious causes
- CT scans and MRI
- Corneal pachymetry
- Intraocular pressure measurement
- Confocal microscopy for suspected atypical infectious keratitis
Additional tests could also be performed if the doctor finds them necessary for a better diagnosis.
Treatment
The treatment of Interstitial keratitis depends on the underlying cause of the condition and its severity.
The primary goal, therefore, is to identify the cause and control inflammation to reduce and prevent pain and any significant scarring.
Medical Therapy
Topical corticosteroids are effective in alleviating symptoms of:
- Pain
- Blurred vision
- Discomfort
They also help in reducing scarring and neovascularization.
Corticosteroids play an important role in local therapy for most bacteria-induced IK but will require systemic antibiotics to treat the underlying disease.
Antibiotics generally form the first-line treatment if a bacterial infection causes the IK.
Similarly, anti-viral medication is recommended if the underlying cause is a viral infection like HSV.
Consult a doctor promptly for the best diagnosis and appropriate treatment since IK might lead to vision loss.
Surgery
In cases of severe IK, surgery may be necessary to prevent or restore vision loss.
Once the inflammation subsides, the cornea is left with deep scars and abnormal blood vessels.
At this point, the only way to restore your sight is to get a cornea transplant.
In cases of corneal thinning or perforation, a patch graft or scleral graft may be necessary to prevent further damage to the eye.
Takeaway
Interstitial Keratitis (IK) is a type of non-ulcerative inflammation of the corneal stroma.
A number of factors, including microbes and auto-immune diseases, could cause this inflammation.
IK has a cloudy, ground-glass-like appearance and can cause eye pain, tearing, photophobia, and haze.
The treatment plan for IK aims at treating the underlying condition causing the keratitis.
Without proper treatment, it can even lead to loss of vision.
Hence, a doctor should be consulted as soon as you suspect any change in your vision to avoid its progression.
Frequently Asked Questions
Can interstitial keratitis be cured?
The chances for recovery in patients with Interstitial keratitis are good. But only if identified and treated before any significant corneal scarring takes place. The treatment plan for IK aims to treat the underlying condition causing the keratitis.
Is interstitial keratitis infectious?
Interstitial keratitis could be both infectious as well as non-infectious. This depends on what is causing the keratitis. Some of the infectious causes of IK include Syphilis, Tuberculosis, Lyme disease, Herpes simplex virus, and Varicella-zoster virus.
What is syphilitic interstitial keratitis?
The most common cause of interstitial keratitis is Syphilis. Syphilis, along with herpes simplex, account for over 50% of cases of IK. Syphilitic keratitis is seen more commonly in people with congenital Syphilis rather than those who acquire it later in life.
What is the most common cause of interstitial keratitis?
The most common cause of interstitial keratitis is syphilis. Syphilis, along with herpes simplex, account for over 50% of cases of IK. Syphilitic keratitis is seen more commonly in people with congenital syphilis rather than those who acquire it later in life.
WowRx uses only high-quality sources while writing our articles. Please read our content information policy to know more about how we keep our content reliable and trustworthy.
