About the Cornea
The cornea, the outermost layer of the eye, is a transparent tissue that helps us see clearly by focusing light onto the retina. It also protects the eye against infections and external factors. When the cornea loses its transparency, it reduces vision quality and may cause pain and light sensitivity.
Congenital structural abnormalities, hereditary diseases, trauma, infections, or degenerative processes can disrupt the shape and clarity of the cornea. Early diagnosis and specialist care play a critical role in preventing permanent vision loss.
Symptoms of Corneal Diseases
Common symptoms seen in corneal problems include:
- Blurred or double vision
- Watery eyes, stinging, itching
- Discharge/crusting, redness, and pain
- Light sensitivity, glare, halos
- Eyelid drooping or frequent blinking
These complaints indicate that you should not delay a regular eye examination.
Common Corneal Diseases
The main conditions that affect corneal health include:
- Keratoconus: Vision impairment caused by progressive thinning and steepening of the cornea.
- Dry eye: Insufficient tear quantity/quality leading to discomfort and reduced surface clarity.
- Herpetic keratitis: A corneal infection caused by the herpes virus.
- Corneal infections and scars: Loss of transparency due to trauma or microbial causes.
- Degenerative disorders: Progressive conditions such as Fuchs dystrophy.
What Is Keratoconus?
Keratoconus is a structural disorder characterized by progressive thinning and conical protrusion of the cornea. Incoming light cannot focus properly on the retina, leading to blurred vision and double vision. It usually progresses in both eyes and, if untreated, may cause permanent vision loss.
The disease is often noticed during adolescence or young adulthood. Continuously increasing astigmatism values during routine exams may raise suspicion. Corneal topography confirms the diagnosis.
Symptoms of Keratoconus
- Blurred or distorted vision
- Continuously increasing glasses prescription and astigmatism
- Light sensitivity and reduced night vision
- Redness, pain, itching
- Headache, double vision, frequent blinking
It may not cause noticeable symptoms in the early stage; therefore, regular topography measurements are important.
Keratoconus Treatments
The treatment method is selected based on the stage of the disease:
- Contact lenses: Soft or rigid gas-permeable lenses help regularize the visual surface.
- Cross-linking: Corneal fibers are strengthened using riboflavin and UV light.
- Corneal ring: Rings placed with femtosecond laser help flatten the cornea.
- Advanced surgery: Keratoplasty or combined treatments may be considered in advanced stages.
Corneal Treatment Process
Contact Lens & Rehabilitation
In early stages, the surface is optimized with lenses to improve visual quality.
Corneal Measurements
Lens selection is guided by topography and aberrometry.
Rigid Gas-Permeable Lens
The front surface is regularized to focus the image.
Regular Follow-up
Lens fit and corneal health are monitored.
Clear Vision & Comfort
Cross-Linking & Corneal Ring
Progression is slowed or halted with procedures that strengthen and reshape the cornea.
Riboflavin Saturation
Corneal fibers are prepared for UV exposure.
UV Irradiation
New bonds are created between fibers.
Ring Placement
Femtosecond laser-assisted rings help flatten the cornea.
Stronger Cornea & Stable Vision
Which method is right for you?
The most suitable approach is planned by evaluating corneal thickness, disease stage, and your expectations.
Dry Eye and Conjunctivitis
Dry eye occurs when the quantity or quality of tears is insufficient. Tears support clarity, lubricate the surface, and help prevent microbes. When inadequate, burning, stinging, blurred vision, and light sensitivity may occur. Treatment includes artificial tears, lifestyle changes, omega-3 support, and—if needed—tear duct plugs.
Conjunctivitis is inflammation of the membrane covering the inner eyelids and the white of the eye. It may affect one or both eyes; blood vessels dilate, causing redness. Causes can be viral, bacterial, or allergic. It is managed with hygiene, appropriate eye drops, and antibiotics when necessary.
Herpetic Keratitis
This infection of the corneal surface caused by the herpes simplex virus tends to recur and may lead to reduced corneal sensation. Severe pain, light sensitivity, dendritic ulcers, and blurred vision are typical findings. Treatment includes antiviral drops or tablets, careful use of corticosteroids when needed, and avoiding factors that irritate the cornea. Early treatment helps prevent permanent scarring.
Corneal Infections and Scars
Bacterial, fungal, or protozoal agents can infect the cornea due to poor contact lens hygiene or after trauma. These rapidly progressing infections may leave permanent scars and reduce transparency. After microbiological cultures, targeted antibiotic/antifungal treatment is applied; if necessary, scar-reducing procedures or keratoplasty may be planned.
Degenerative Corneal Diseases
In degenerative conditions such as Fuchs endothelial dystrophy, corneal endothelial cells gradually decrease over time; swelling, morning haze, and light scatter may occur. Treatment includes hypertonic drops, protective measures, and in advanced cases surgeries such as endothelial keratoplasty (DMEK/DSEK). Regular follow-up is critical for monitoring progression and timing surgery appropriately.