Astigmatism is a common eye condition where the eye’s cornea (clear front surface) or lens has an irregular, often egg-like shape, rather than being perfectly round. This altered curvature causes light to focus unevenly on the retina, leading to blurred or distorted vision at all distances.
The Nature of Astigmatism Progression
Astigmatism often remains stable after childhood, though minor prescription fluctuations can occur. However, it can change or develop at any age, and its severity may increase. Progression often signals an underlying factor, making monitoring these changes important for ongoing eye care.
Factors That Can Worsen Astigmatism
Age-related changes are a common reason for astigmatism progression. As people age, the eye’s lens can stiffen and change shape, and corneal alterations can occur, affecting light refraction. Cataracts, a clouding of the eye’s lens, can also worsen astigmatism if misshapen.
Certain eye diseases can directly impact corneal shape and lead to increased astigmatism. Keratoconus is a progressive condition where the cornea thins and bulges outward into a cone shape, distorting vision and often causing irregular astigmatism. It typically begins in the teenage years or early adulthood, worsening over 10 to 20 years until progression stabilizes. Other corneal dystrophies, such as Fuchs’ endothelial dystrophy, can also damage corneal cells, leading to fluid buildup and shape changes, worsening astigmatism.
Eye injury or surgery can also induce or alter astigmatism. Trauma to the eye, such as scratches or scars on the cornea, changes its shape. Certain eye surgeries, like cataract surgery or corneal transplants, may result in new or worsened astigmatism from lens or corneal alterations. Frequent or vigorous eye rubbing can sometimes contribute to corneal irregularities, particularly in individuals susceptible to conditions like keratoconus.
Identifying Changes and Seeking Professional Guidance
Recognizing changes in vision can indicate that astigmatism might be worsening. Common symptoms include increased blurriness or distortion, especially at night. Individuals might also experience eye strain, headaches, or squinting to see clearly. These symptoms arise because the eyes work harder to focus.
Regular comprehensive eye examinations are important for monitoring eye health and detecting changes early. During an exam, an eye care professional assesses vision changes, measures the cornea’s curve (e.g., keratometry), and evaluates light focus through a refraction test. Consult an eye care professional if new symptoms appear or if vision changes suddenly.
Managing Astigmatism Changes
Options are available to correct vision if astigmatism worsens. Eyeglasses with cylindrical lenses commonly focus light correctly on the retina, improving blurry vision. Contact lenses also provide a solution, with prescriptions updated to accommodate changes in astigmatism.
For more complex or irregular astigmatism, such as with keratoconus, specialized contact lenses may be prescribed. Toric contact lenses correct astigmatism by compensating for the eye’s uneven curvature, providing clear and stable vision. Rigid gas permeable (RGP) lenses are another option for moderate to severe irregular astigmatism, creating a smooth refractive surface over the irregularly shaped cornea.
Surgical options are also available for managing astigmatism. Refractive surgeries like LASIK (Laser-Assisted In Situ Keratomileusis) and PRK (Photorefractive Keratectomy) reshape the cornea to correct astigmatism, providing a long-term solution for stable cases. For progressive conditions like keratoconus, corneal cross-linking can strengthen the cornea and halt progression.