Corneal Ulcer Symptoms, Causes and Treatment

How Does a Corneal Ulcer Develop?

The cornea is a transparent tissue without blood vessels that allows light to enter the eye. The tear film and the outer epithelial layer of the cornea protect the ocular surface against external factors. When the integrity of the epithelium is disrupted, bacteria, fungi, viruses or other microorganisms may enter the corneal tissue. In some cases, immune system-related processes may cause tissue loss in the cornea even when no infection is present. As the wound progresses, the regular structure of the cornea becomes disrupted and its transparency may decrease. The location and depth of the damage determine its effect on vision.

A corneal ulcer does not progress at the same rate or in the same way in every patient. Some infections may deepen rapidly, while others progress more slowly. The open area on the corneal surface may extend into the underlying supporting tissue. As inflammation increases, a white or grey area may become visible in the cornea. Advanced cases may involve corneal thinning and a risk of perforation. The treatment plan is determined according to the size, location and possible cause of the wound.

Causes of Corneal Ulcers

The causes of corneal ulcers can be divided into two main groups, infectious and non-infectious factors. Microorganisms such as bacteria, fungi, herpes viruses and Acanthamoeba may cause infectious ulcers. Using contact lenses under inappropriate conditions may leave the ocular surface vulnerable to infection. Eye trauma, chemical exposure and injuries involving plant material may also increase the risk. Advanced dry eye, incomplete eyelid closure and certain rheumatic diseases may contribute to the development of non-infectious ulcers. Identifying the underlying cause is important for selecting appropriate treatment.

Conditions that may contribute to the development of a corneal ulcer include:

• Bacterial infections.
• Fungal infections.
• Herpes virus infections.
• Acanthamoeba infection.
• Incorrect use of contact lenses.
• Eye trauma and chemical exposure.
• Severe dry eye.
• Incomplete eyelid closure.
• Autoimmune or rheumatic diseases.

Bacterial Corneal Ulcers

Bacteria are among the common causes of corneal ulcers. A healthy corneal surface forms a protective barrier against microorganisms entering the tissue. When a scratch or epithelial defect develops, bacteria may reach the deeper layers of the cornea. Bacteria such as Staphylococcus species and Pseudomonas may cause different clinical presentations. Some bacterial infections may progress more rapidly, particularly in contact lens users. Severe eye pain, redness, discharge and a white area on the cornea should be assessed for bacterial infection.

The severity of a bacterial ulcer varies according to the type of microorganism and the depth of the wound. Inflammatory cells may accumulate in the front of the eye in some patients. Large ulcers or those located close to the visual centre require closer monitoring. Treatment is generally started with appropriate antibiotic eye drops. More intensive eye drop treatment or hospital monitoring may be required in severe cases. Medication is selected by considering the clinical findings and, when necessary, culture results.

Contact Lenses and the Risk of Infection

Contact lens use may increase the risk of corneal ulcers, particularly when hygiene rules are not followed. Sleeping in contact lenses, wearing them for longer than recommended and failing to clean the storage case adequately are important risk factors. Allowing lenses to come into contact with tap water may also increase the likelihood of infection. Wearing contact lenses in the shower, swimming pool or sea may make it easier for certain microorganisms to reach the eye. Minor surface damage occurring while wearing contact lenses may predispose the eye to infection. If pain or redness develops, the lenses should be removed and the eye assessed on the same day.

Behaviours that increase the risk of contact lens-related infection include:

• Sleeping in contact lenses.
• Rinsing lenses with tap water.
• Failing to replace the lens case regularly.
• Reusing old solution.
• Showering in contact lenses.
• Wearing lenses in a swimming pool or the sea.
• Continuing to wear lenses beyond their recommended replacement period.

It is important to use contact lens solution correctly and clean the storage case regularly. Hands should be washed and dried before inserting contact lenses. The replacement schedule for daily or monthly lenses should follow the manufacturer's recommendations. Contact lens use should be discontinued if irritation, blurred vision or sensitivity to light develops. Even if the symptoms resolve, the same lenses should not be used again without an assessment. In patients with a suspected infection, the lenses and storage case may be examined when necessary.

Fungal and Acanthamoeba Infections

Fungal corneal ulcers may occur particularly after eye injuries involving plant material. Contact with a tree branch, thorn or leaf may pose a risk. Some fungal infections may progress into deeper areas of the cornea. Treatment may take longer and require different medications than bacterial infections. Acanthamoeba is a microscopic organism that may be found in water and the environment. Allowing contact lenses to come into contact with tap water or swimming while wearing lenses may increase the risk of infection.

In Acanthamoeba infection, eye pain may sometimes be more pronounced than the findings visible during examination. However, not every patient experiences pain of the same severity. Delayed diagnosis may make treatment more difficult. Conventional antibiotic eye drops alone are not sufficient for fungal or Acanthamoeba infections. Specific medications targeting the causative organism and regular follow-up are required. Treatment is planned according to the extent of corneal damage and the laboratory findings.

Herpes and Viral Corneal Ulcers

Herpes simplex virus may cause recurrent infections of the corneal surface. Some patients develop branching superficial wounds on the cornea. Stress, febrile illnesses and conditions affecting the immune system may contribute to the development of episodes. Recurrent infections may gradually reduce corneal sensitivity. This may affect the ability of the ocular surface to protect and heal itself. Varicella-zoster virus may also cause significant problems around the eye and in the cornea in some patients.

Antiviral medications are considered when treating viral corneal ulcers. Whether treatment is administered as eye drops, ointment or oral medication depends on the clinical condition. Unsupervised use of corticosteroid eye drops in an eye with a herpes infection may worsen the condition in some cases. However, corticosteroid treatment may be considered for certain herpes-related conditions only with appropriate antiviral protection and close monitoring. Medication must therefore be selected according to the type of infection. The intervals between follow-up examinations and the need for preventive treatment are assessed separately in patients with recurrent disease.

Non-Infectious Corneal Ulcers

Corneal ulcers are not always caused by microorganisms. Rheumatoid arthritis and certain other autoimmune diseases may cause inflammation and thinning around the edge of the cornea. In these cases, tissue damage caused by the immune system is the primary problem. Incomplete eyelid closure may also cause prolonged exposure of the cornea to the external environment. Pronounced dryness may develop when the ocular surface remains exposed because of facial paralysis or structural eyelid abnormalities. In advanced cases, persistent surface damage and corneal ulcers may develop.

The treatment approach for non-infectious ulcers differs from that used for infectious cases. It must first be determined whether the corneal wound is caused by an infection. Conditions associated with rheumatic diseases may require follow-up in collaboration with the relevant specialties. Protective eye drops, ointments or surgical options may be considered if there are problems with eyelid closure. Some patients may require medication that regulates the immune system. The scope of treatment is determined according to the degree of corneal thinning and the underlying disease.

Dry Eye and Corneal Damage

The tear film helps keep the corneal surface moist and protects it from external factors. In advanced dry eye, the cells on the corneal surface may become damaged more easily. This damage may initially appear as small surface abnormalities. If tear deficiency persists, healing of the corneal epithelium may become more difficult. This may also predispose some patients to infection. Severe dryness accompanying autoimmune diseases requires particularly careful assessment.

Not every case of dry eye develops into a corneal ulcer. However, severe dryness, incomplete eyelid closure or reduced corneal sensitivity may increase the risk. Artificial tear drops, protective gels and appropriate ocular surface treatments may provide support. Treating an underlying eyelid or immune system problem is also important. Pronounced eye pain, sensitivity to light or reduced vision requires further assessment. Treatment is arranged according to the degree of damage to the corneal surface.

What Are the Symptoms of a Corneal Ulcer?

Symptoms of a corneal ulcer may vary according to the location and depth of the wound and the cause of the infection. Severe eye pain and a foreign body sensation are among the common complaints. Eye redness, excessive watering and sensitivity to light may also occur. Some patients develop inflammatory discharge and eyelid swelling. A white or grey area may be visible on the cornea. Blurred vision may be more pronounced if the wound is close to the visual centre.

The main symptoms that may occur with a corneal ulcer include:

• Severe eye pain.
• Irritation and a foreign body sensation.
• Pronounced redness.
• Sensitivity to light.
• Excessive watering.
• Inflammatory discharge.
• Blurred vision.
• Eyelid swelling.
• A white or grey spot on the cornea.

The severity of pain is not the same in every patient. People with reduced corneal sensitivity may have a significant wound despite experiencing only limited pain. New pain and redness in contact lens users must be assessed particularly carefully. A white spot on the eye or rapidly decreasing vision requires urgent examination. Unsupervised eye drops used at home may delay appropriate treatment. An eye examination should be performed on the same day when these symptoms occur.

How Is a Corneal Ulcer Diagnosed?

During diagnosis, the eye is examined in detail using a special instrument called a slit lamp. The size and depth of the corneal wound and its proximity to the central visual area are assessed. Fluorescein dye applied to the ocular surface may help identify areas of epithelial loss. Inflammation around the cornea and cellular reactions in the front of the eye are also examined. Eyelid structure, contact lens use and previous diseases are included in the assessment. Additional laboratory tests may be required in severe cases or those with an unusual clinical course.

The main factors considered during diagnosis include:

• Size of the corneal wound.
• Central or peripheral location of the wound.
• Depth of tissue damage.
• Characteristics of white areas on the cornea.
• Inflammation in the front of the eye.
• History of contact lens use.
• History of trauma or contact with plant material.
• Accompanying dry eye and eyelid problems.

Examination findings may provide information about the possible infectious organism. However, it is not always possible to determine the exact type of microorganism from its appearance alone. A more detailed examination may be required, particularly for large, deep or centrally located ulcers. Recurrent wounds and cases that do not respond to initial treatment are assessed separately. If there is a risk of corneal perforation, examination and treatment are planned urgently. The timing of treatment is determined according to the severity of the wound and the clinical findings.

Corneal Scraping and Culture Tests

In some corneal ulcers, a sample may be taken from the wound to identify the causative microorganism. During this procedure, a small scraping sample is collected from an appropriate area of the corneal surface. The samples may be examined in a laboratory for bacteria, fungi or other organisms. Culture results may provide information about which medications the microorganism may be sensitive to. However, culture sampling is not required for every corneal ulcer. The size and location of the wound and its response to treatment influence the decision to collect a sample.

Culture testing may be particularly important for central, large or deep ulcers. Laboratory assessment may also be required in patients who have started treatment but are not improving. Appropriate tests are planned separately if a fungal or Acanthamoeba infection is suspected. When possible, samples may be collected before treatment begins. However, necessary treatment should not be delayed unnecessarily in severe infections. Existing medications may subsequently be adjusted according to the culture results.

How Is a Corneal Ulcer Treated?

Treatment of a corneal ulcer is planned according to its cause and the degree of corneal tissue involvement. Appropriate antibiotic eye drops are used in patients with a suspected bacterial infection. Antifungal medications are considered for fungal infections, while antiviral treatments are used for viral infections. Specific medications may be required when other microorganisms such as Acanthamoeba are involved. Treatment intensity varies according to the size and depth of the ulcer and its proximity to the visual centre. More frequent administration of eye drops or hospital monitoring may be required in severe cases.

Using medications as recommended and at the specified intervals is important for treatment. Follow-up examinations assess whether the wound is becoming smaller and whether corneal thinning is continuing. Additional treatments may be required to reduce eye pain or control inflammation inside the eye. Corticosteroid eye drops should not be used before the infectious organism has been identified and the necessary assessment performed. However, they may be considered in selected cases under close monitoring after the infection has been brought under control. The duration of treatment varies according to the microorganism and the eye's response.

Fortified Antibiotic Eye Drops

Standard eye drops may not always be sufficient for large, deep bacterial ulcers or those threatening the visual centre. Fortified antibiotic eye drops may be considered in these situations. These medications are specially prepared under appropriate conditions. The purpose is to deliver a sufficient concentration of antibiotics to the area of infection. The antibiotics used are selected according to the clinical findings and culture results, when available. The frequency of administration is determined according to the severity of the infection.

Fortified drops are not necessary for every corneal ulcer. Commercially available antibiotic eye drops may be sufficient for some patients. Because intensive medication may temporarily irritate the ocular surface, regular follow-up is important. The frequency and content of the medications may be adjusted as treatment progresses. Attention must be paid to the preparation and storage conditions of the drops. Appropriate medication is selected by considering the type of infection and the clinical characteristics of the wound.

Surgical Treatment for Corneal Perforation

As a corneal ulcer progresses, the tissue may become significantly thinner in some patients. Increasing thinning may lead to a risk of corneal perforation and leakage of intraocular fluid. Tissue adhesive and a bandage contact lens may be used in suitable patients with small perforations. This method aims to protect the integrity of the eye temporarily. Surgical intervention may be required for larger perforations or infections that cannot be brought under control. The procedure used is determined according to the size of the damage and the condition of the infection.

Corneal transplantation may be considered in some severe cases. During this procedure, known as therapeutic keratoplasty, damaged or infected corneal tissue is removed and replaced with suitable donor tissue. The purpose of surgery is to control the infection and preserve the anatomical integrity of the eye. Vision cannot be expected to return completely to its previous level after every transplant. Postoperative monitoring is required for infection, tissue rejection and the need for further treatment. Treatment is selected by considering the current condition of the eye and the extent of the wound.

Amniotic Membrane Procedures

In some corneal ulcers, closure of the open surface may be delayed after the infection has been brought under control. An amniotic membrane procedure may be considered to support healing of the ocular surface in this situation. The amniotic membrane is a biological tissue prepared under appropriate medical conditions. It may help protect the corneal surface and support the healing environment. The application method varies according to the size and depth of the wound. This method is not required for every corneal ulcer.

The amniotic membrane is surgically placed in some patients. It may also be used with different delivery systems in suitable cases. This procedure does not replace medication targeting the infection. Inflammation of the ocular surface and the existing infection must also be brought under control. Closure of the cornea is monitored through regular examinations after treatment. The expected healing time varies from patient to patient.

Corneal Scarring and Visual Quality

Scar tissue may remain where the wound was located after a corneal ulcer heals. This scar may reduce corneal transparency and affect visual quality. The degree of blurring depends on the scar's proximity to the visual centre. Irregular astigmatism may also develop in some patients. Laser methods such as phototherapeutic keratectomy may be considered for superficial scars with suitable characteristics. However, not every corneal scar is suitable for laser treatment.

The infection must be completely under control before laser treatment is considered. Corneal thickness, scar depth and the general condition of the ocular surface are examined in detail. Different surgical options may be required for deeper or more extensive scars. Special contact lenses may help improve visual quality in some patients. Corneal transplantation may also be considered at a later stage to support vision in advanced cases. The treatment decision is determined according to the characteristics of the residual corneal damage.

Potential Complications of Corneal Ulcers

A corneal ulcer may cause permanent changes to the ocular surface if not treated appropriately. The development of corneal scar tissue may reduce transparency. Irregular astigmatism may prevent vision from being adequately corrected with glasses. Intraocular pressure may increase in some patients, leading to secondary glaucoma. Corneal perforation or intraocular infection may occur in advanced cases. The risk of complications varies according to the cause and depth of the ulcer and how early treatment is started.

Potential complications include:

• Permanent corneal scarring.
• Irregular astigmatism.
• Reduced vision.
• Secondary glaucoma.
• Cataract development.
• Corneal thinning.
• Corneal perforation.
• Intraocular infection.
• Need for additional surgery.

Not every corneal wound causes permanent vision loss. Small, peripherally located ulcers may leave more limited scarring with appropriate treatment. Deep ulcers close to the visual centre carry a higher risk of permanent impairment. Spread of the infection into the eye is a serious condition requiring urgent intervention. Regular follow-up allows the response to treatment and potential complications to be monitored. If symptoms increase, the scheduled follow-up date should not be awaited.

Methods of Preventing Corneal Ulcers

To reduce the risk of corneal ulcers, attention should be paid to conditions that irritate the ocular surface and predispose the eye to infection. Contact lens users must follow cleaning and replacement schedule instructions. Contact between lenses and tap water, swimming pool water or seawater should be avoided. Protective glasses may be worn during gardening or work involving a risk of foreign bodies entering the eye. Patients with advanced dry eye or incomplete eyelid closure require regular monitoring. Eye drops should not be used without an individual assessment.

Preventive measures include:

• Maintaining contact lens hygiene.
• Not sleeping in contact lenses.
• Not cleaning lenses with tap water.
• Not showering or swimming in contact lenses.
• Wearing protective glasses during high-risk work.
• Continuing dry eye treatment regularly.
• Having eye trauma assessed without delay.
• Not using corticosteroid eye drops without medical supervision.

When Is Urgent Assessment Required?

Severe eye pain, pronounced redness and sensitivity to light are symptoms that should be assessed for a possible corneal ulcer. A sudden reduction in vision or a white spot on the cornea also requires urgent examination. The combination of pain and redness is particularly important in contact lens users. The lenses should be removed, and the eye should be assessed on the same day. Symptoms developing after chemical exposure or eye trauma should also be assessed without delay. You can contact me using the details on my website to arrange follow-up and examination.