Keratoconus: Early Signs, Diagnosis and Modern Treatment Options
What Is Keratoconus?
Keratoconus is a condition in which the cornea the clear, dome-shaped front surface of the eye becomes progressively thinner and changes shape. Instead of maintaining its normal rounded shape, the cornea can become more cone-shaped and irregular.
Because the cornea is responsible for a significant part of the eye’s focusing power, these changes can affect the way light enters the eye and lead to blurred or distorted vision. Keratoconus commonly develops during the teenage years or early adulthood, although the age and rate of progression can vary between individuals. (National Eye Institute)
One of the important features of keratoconus is that no two patients necessarily have the same pattern of disease. The amount of corneal thinning, irregularity, visual symptoms and progression can differ considerably. This is why treatment needs to be based on a detailed assessment of the individual eye rather than a one-size-fits-all approach.
What Are the Early Signs of Keratoconus?
In its early stages, keratoconus may be mistaken for an ordinary change in spectacle power or astigmatism.
Common symptoms may include:
- Increasing or frequently changing spectacle prescription
- Blurred or distorted vision
- Increasing astigmatism
- Difficulty achieving clear vision with glasses
- Increased sensitivity to light
- Glare or halos, particularly at night
- Ghosting or multiple images
- Difficulty seeing clearly despite updated spectacles
- Frequent changes in contact lens prescription
Some patients may initially have relatively good vision and only subtle changes in the corneal shape. This makes appropriate corneal evaluation important when there is unexplained or progressive visual change.
Why Does Keratoconus Progress?
The exact cause of keratoconus is not completely understood. Several genetic, environmental and mechanical factors may contribute.
Eye rubbing is an important factor that doctors commonly consider, particularly in patients with allergic eye disease or chronic eye irritation. Patients with keratoconus are generally advised to avoid vigorous eye rubbing and to address underlying allergy or ocular surface problems.
The disease may progress at different rates. Some patients remain relatively stable, while others experience significant changes in corneal shape and vision over time. Monitoring the cornea helps determine whether the condition is stable or progressing.
How Is Keratoconus Diagnosed?
A routine eye examination may detect changes in vision, but diagnosing and monitoring keratoconus requires detailed assessment of the cornea.
Your ophthalmologist may evaluate:
Corneal Topography and Tomography
These tests create detailed maps of the corneal surface and shape. They help identify irregularities that may not be visible during a routine eye examination.
Corneal Thickness
Measuring corneal thickness can provide important information about the structural condition of the cornea and helps in treatment planning.
Refraction and Visual Acuity
Changes in spectacle power, astigmatism and best-corrected vision are important when assessing disease progression.
Slit-Lamp Examination
A detailed examination of the cornea can identify clinical signs associated with keratoconus and other corneal conditions.
The combination of these findings allows the ophthalmologist to determine the severity and progression of the disease and select an appropriate treatment strategy.
Can Keratoconus Be Treated?
Yes. Treatment depends on the stage of keratoconus, the amount of corneal irregularity, visual requirements, contact lens tolerance, corneal thickness and whether the disease is progressing.
Treatment may range from vision correction with specialised lenses to procedures designed to stabilise or reshape the cornea.
1. Glasses
In early keratoconus, spectacles may provide adequate vision correction. However, as corneal irregularity increases, glasses may no longer provide satisfactory visual quality.
2. Specialised Contact Lenses
Rigid gas-permeable, scleral and other specialty contact lenses can help improve vision by creating a more regular optical surface over an irregular cornea.
These lenses do not necessarily stop the underlying disease from progressing; their primary role is visual rehabilitation.
3. Corneal Collagen Cross-Linking
Corneal collagen cross-linking, commonly referred to as C3R or CXL, is primarily intended to stabilise progressive corneal ectasia rather than simply improve spectacle power.
During the procedure, riboflavin is used with controlled ultraviolet-A exposure to strengthen the collagen structure of the cornea. It is most useful when there is evidence that the keratoconus is progressing. (EyeWiki)
The decision to perform cross-linking is based on factors such as changes in refraction, visual acuity and corneal topography or tomography.
4. Corneal Ring Segments
Intrastromal corneal ring segments, such as INTACS or other appropriate ring-segment procedures, may be considered in selected patients to alter corneal shape and improve visual rehabilitation.
These procedures are not suitable for every patient, and careful corneal assessment is necessary before considering them.
5. Topography-Guided Treatment
In selected cases, topography-guided procedures may be considered to address significant corneal irregularity. Patient selection is critical because corneal tissue availability and disease stability must be evaluated carefully.
6. ICL
For selected patients with significant refractive error, an Implantable Collamer Lens (ICL) may be considered as part of the overall visual rehabilitation strategy. An ICL is a phakic intraocular lens placed inside the eye while the natural crystalline lens remains in place. Suitability depends on factors including age, refractive error, anterior chamber dimensions and overall ocular health. (U.S. Food and Drug Administration)
7. Corneal Transplant
In advanced keratoconus, particularly when there is significant corneal scarring or when satisfactory vision cannot be achieved with contact lenses, corneal transplantation may become necessary. (National Eye Institute)
Depending on which layers of the cornea are affected and the condition of the endothelium, procedures such as DALK or, in selected situations, penetrating keratoplasty may be considered. DALK preserves the patient’s healthy endothelium and is commonly used for keratoconus when the deeper corneal layers remain suitable. (EyeWiki)
Why Early Evaluation Matters
Keratoconus is not simply a problem of increasing spectacle power. It is a structural disease of the cornea that may progress over time.
Early diagnosis allows your ophthalmologist to establish a baseline and monitor changes in corneal shape and vision. If progression is detected, treatment such as corneal cross-linking may be considered to help stabilise the condition.
At Pristine Eye Clinic, keratoconus management is tailored to the individual patient, ranging from specialised contact lenses and corneal cross-linking to advanced procedures and corneal transplantation when required.