What Causes Corneal Scarring and How Is It Treated?

Prof Donald Tan Tiang Hwee

MBBS (S'pore), FRCS (Glas), FRCS (Edin), FRCOphth (UK), FAMS

Ophthalmologist

Partner and Senior Consultant

Dr Chan Wing Kwong

MBBS (S'pore), MMed (Ophth), FRCS (Edin), FRCOphth, FAMS

Ophthalmologist

Partner and Senior Consultant

Dr Anna Tan Wee Tien

MBBS (S'pore), MMed (Ophth), MRCSEd, FAMS

Ophthalmologist

Partner and Senior Consultant

The cornea is the clear front surface of the eye. A scar can block or scatter light passing through it, while changes to its shape can distort how light is focused. This may disrupt a person’s vision, particularly if the scar is in the centre of the cornea.

An eye examination can establish where the scar is, how deep it extends and how much it affects your sight. Those findings help determine whether vision can be managed without surgery or whether a procedure may help.

Read on to learn how corneal scarring can affect your sight, how cornea specialists assess this damage and the treatment options that may be considered.

What Causes Corneal Scarring?

A corneal scar can form when an injury, infection or inflammation damages the cornea. As the tissue heals, it may become cloudy rather than returning to its usual clarity. That cloudiness can make it harder for light to pass through the eye.

Several conditions and injuries can lead to corneal scarring, including:

• Eye infections: Bacterial, viral, fungal or parasitic infections can damage the cornea and may leave scarring, particularly when the infection is severe or affects deeper tissue.
• Eye injuries: Scratches, foreign objects, chemical exposure and other forms of trauma may leave a scar after the cornea heals.
• Corneal inflammation: Persistent or severe inflammation can damage corneal tissue and affect its transparency.
• Previous eye procedures: In some cases, scarring may occur as part of the healing response following an eye procedure or surgery.

How Does Corneal Scarring Affect Vision?

A corneal scar can reduce transparency and prevent light from passing cleanly through the eye. It may also create an uneven corneal surface that changes how light is focused. Depending on the characteristics of the scar, a person may experience blurred or hazy vision, glare, light sensitivity or distorted vision.

Not every corneal scar causes the same degree of visual difficulty. A small scar away from the centre of the cornea may have little effect on vision, while one in front of the pupil can scatter or block the light needed for clear sight.

How Is Corneal Scarring Assessed?

Corneal scarring is assessed by examining the scar itself, checking how it affects your vision and determining whether an active condition is still affecting the cornea.

Your eye specialist may ask when your symptoms began and whether you have had an eye infection, injury, inflammation or previous eye surgery. This can help identify what caused the scar and whether an active problem still needs treatment.

The examination may then include:

• A visual acuity test: This measures how clearly you can see and helps establish the extent to which your vision has been affected.
• A close-up examination of the cornea: This allows the specialist to assess the scar’s location, size and appearance, as well as look for signs of active infection or inflammation.
• Additional corneal measurements or imaging: If required, advanced tests may be used to examine the cornea’s shape, thickness and individual layers in greater detail.

These findings can show whether the scar is superficial or extends into deeper corneal tissue. The assessment also helps establish whether reduced vision is mainly caused by the scar or whether another eye condition may be contributing. Your specialist can then determine whether monitoring, vision correction, non-surgical treatment or a surgical procedure may be appropriate.

Managing Corneal Scarring Without Surgery

Non-surgical treatment for corneal scarring focuses on improving vision, managing any active eye condition and monitoring scars that do not significantly affect sight. Depending on how the scar affects the cornea, management may include glasses, specialised contact lenses or observation.

Glasses may improve vision if the scar has changed how the eye focuses light. If scarring has made the corneal surface irregular, specialised contact lenses may provide clearer vision by creating a smoother optical surface.

If an infection or inflammation is still affecting the cornea, your specialist will need to treat that condition as well as assess the scar. Otherwise, it could continue to damage the cornea or cause further scarring, even if treatment improves the existing scar. Once the active problem is controlled, the specialist can assess what effect the remaining scar has on your vision.

These approaches generally do not remove established scar tissue. Rather, they aim to improve vision where possible, address active corneal conditions and determine whether further treatment may be needed.

When May Surgery Be Considered for Corneal Scarring?

In the event that corneal scarring significantly affects vision and non-surgical approaches have not provided adequate improvement, your ophthalmologist may recommend corneal surgery to reduce the effect of the scar and improve your sight.

There are several potential surgical approaches and the procedure considered will depend mainly on the scar’s location and depth.

• Laser treatment for superficial scarring: This procedure treats superficial scars that affect the clarity or smoothness of the cornea. The surgeon uses a laser to remove a thin layer of tissue from the cornea, creating a clearer and smoother surface.
• Partial-thickness corneal transplant: This procedure may be considered when the scar affects the front layers of the cornea but the innermost layer remains healthy. Your surgeon will remove the affected outer layers and replace them with donor tissue while leaving the healthy inner layer intact.
• Full corneal transplant: For deeper and more extensive scarring, your ophthalmologist may recommend a full corneal transplant. During this procedure, the surgeon removes the full thickness of the damaged central cornea and replaces it with healthy donor tissue.

Patients exploring cornea repair surgery should undergo a detailed assessment to determine the depth and location of the scar and whether the potential benefits of surgery outweigh its risks.

What Should You Consider Before Corneal Scar Treatment?

The goal of treatment is not necessarily to restore full clarity to the cornea. Instead, treatment is generally considered according to how much the scar affects functional vision and whether intervention is likely to provide meaningful improvement.

Factors that may influence treatment decisions include the cause and stability of the scar, the health of the remaining corneal tissue and whether other eye conditions are also affecting sight. The potential benefits, limitations and recovery involved with each option should also be discussed before proceeding.

Because corneal scars vary between individuals, there is no single treatment approach that is suitable for everyone. An individual consultation allows an eye doctor to assess the characteristics of the scar, understand how it affects your vision and discuss which management options may be appropriate for you.

Explore Corneal Scar Treatment Options at Eye & Cornea Surgeons

If you have noticed changes in your vision or are concerned about a corneal scar, seeking medical advice can help you better understand your condition and the next steps to consider. A thorough assessment can establish the extent of the scarring, clarify whether treatment is needed and provide greater peace of mind about how your eye health is being managed.

At Eye & Cornea Surgeons, care for corneal scars and other eye conditions are led by our team of ophthalmologists. Prof Donald Tan Tiang Hwee, Dr Chan Wing Kwong and Dr Anna Tan Wee Tien draw on their experience in corneal disease and surgery to help you weigh what treatment could realistically achieve against its risks and recovery. This includes discussing whether glasses or specialised contact lenses may be enough, or whether surgery offers a meaningful chance of improving your sight.

If you are concerned about corneal scarring or have noticed recent changes in your vision, book an appointment with us for a personalised consultation.