Journal of Eye Diseases and Disorders

Keratoconus: A Gradual Shift in Corneal Shape and Clarity

Marcus Delling^* Department of Optometric Research, Vellmere University, Oslo, Norway
^*Correspondence: Marcus Delling, Department of Optometric Research, Vellmere University, Oslo, Norway, Email:

Received: 01-Sep-2025 Editor assigned: 03-Sep-2025 Reviewed: 17-Sep-2025 Revised: 24-Sep-2025 Published: 01-Oct-2025, DOI: 10.35248/2684-1622.25.10.291

Description

Keratoconus is an eye disorder in which the normally round, dome-shaped cornea becomes thin and gradually develops a cone-like bulge. This irregularity interferes with the eye’s ability to focus properly and results in distorted vision. The changes typically begin during the teenage years or early adulthood and may progress for ten to twenty years before stabilizing. Individuals affected often experience increasing visual difficulties that cannot be fully corrected by glasses alone.

The cornea serves as the eye’s primary focusing surface. When its shape becomes irregular, light entering the eye fails to focus accurately on the retina. This can cause images to appear blurry or distorted. Those with keratoconus often report sensitivity to light, frequent changes in eyeglass prescriptions, difficulty seeing at night, and problems with glare. The condition may affect one or both eyes, although it is often more advanced in one eye than the other.

In the early stages, the condition may be mistaken for simple nearsightedness or astigmatism. However, as it progresses, vision correction with standard lenses becomes less effective. In more advanced cases, the cornea becomes increasingly thin and protruded, which results in severe visual impairment. The progression can be unpredictable, with some people experiencing rapid changes over a few years and others noticing very slow development over decades.

The exact cause of keratoconus is not fully understood. Genetic factors are believed to play a role, as the condition often runs in families. It is also more common in people with certain systemic or connective tissue disorders. Chronic eye rubbing has been associated with progression and may act as a contributing factor. Conditions such as allergies, which cause frequent eye irritation and rubbing, have also been linked with higher incidence rates.

Diagnosis typically involves a thorough eye examination that includes corneal topography, a method that maps the surface curvature of the cornea. This tool can detect early signs of distortion even before symptoms become noticeable. In addition, measurements of corneal thickness and visual acuity assessments are used to evaluate the extent of the condition. Specialized imaging techniques can provide further insights into corneal structure and help determine the stage of the disorder.

Management of keratoconus depends on its severity. In mild to moderate cases, glasses or soft contact lenses may initially provide adequate correction. As the condition advances, rigid gas permeable lenses or hybrid lenses, which combine a hard center with a soft outer ring, are often used. These lenses help to create a smooth refractive surface by masking the irregular shape of the cornea. However, they can be uncomfortable for some users and may require frequent adjustments to maintain fit and effectiveness.

Another widely used method for slowing the progression of the disease is corneal collagen cross-linking. This procedure involves applying riboflavin drops to the cornea and activating them with ultraviolet light. The goal is to strengthen the corneal tissue by increasing the connections between collagen fibers, which can reduce the likelihood of further deformation. This treatment is most effective in early to moderate stages and is less beneficial once the cornea has become severely distorted.

In more advanced cases, when vision can no longer be improved with contact lenses or when scarring has developed, surgical options may be considered. One common procedure is the implantation of intracorneal ring segments. These small, curved devices are inserted into the cornea to flatten it and improve visual function. In severe cases, a corneal transplant may be required. This involves replacing the damaged cornea with healthy donor tissue. Although the procedure has a high success rate, recovery may take several months, and there are potential risks such as rejection or infection.

Conclusion

People living with keratoconus often face daily challenges related to fluctuating vision and dependence on specialized corrective devices. Adaptation to these changes can affect education, employment, and personal activities, especially when the condition develops during formative years. Supportive care, including guidance from vision specialists and access to assistive technologies, can help individuals adjust to visual limitations. Regular monitoring is essential to track progression and evaluate treatment options as the condition evolves.