An irregular cornea may occur as a result of trauma, scarring following inflammation or due to corneal disease such as keratoconus or pellucid marginal degeneration.
An irregular cornea may occur as a result of trauma, scarring following inflammation or due to corneal disease such as keratoconus or pellucid marginal degeneration.The latter may be mild cases that go undetected for years, with the only symptoms being unsatisfactory quality of vision with spectacles and soft disposable contact lenses.
Keratoconus is a disease affecting the cornea, the transparent front part of the eye. The cornea becomes progressively thinner and bulges outward like a cone, causing distorted blurred vision. Onset is usually in puberty or late teens. Cases may vary from mild (where affected individuals may achieve adequate vision with spectacles or soft contact lenses) to severe where corneal scarring occurs and transplant surgery may be necessary.
Pellucid marginal degeneration
Pellucid marginal degeneration or PMD is often confused with keratoconus. Though both conditions cause thinning of the cornea, with PMD the thinning tends to be in the inferior and peripheral areas of the cornea. Onset is usually 20 – 40 years of age.
With both keratoconus and PMD, optimal vision can usually be achieved with either rigid gas permeable (RGP) or scleral contact lenses. Your optometrist will discuss the options with you to determine the treatment best suited to your needs.