Keratoconus (also known as Pellucid) is a progressive non-inflammatory disorder that causes a characteristic thinning and cone-like steepening of the cornea. This steepening in your cornea results in distortion of vision, increased sensitivity to glare and light and an associated reduction in visual acuity.
These symptoms usually appear in the late teens and early twenties. Keratoconus may progress for 10-20 years and then can slow. Each eye can be affected differently. This can result in a dramatic decrease in the ability to see clearly even with corrective lenses. (Note: as Keratoconus and pellucid are the same disease process, any reference to “Keratoconus” on this site also applies to “pellucid” as well.)
Keratoconus is a non-inflammatory, degenerative eye disease that compromises the strength of your collagen fibers. Imagine that a normal cornea is made up of sheets of collagen, one stacked on top of the other (just like sheets of plywood stacked up). If there was a weak spot in the collagen or plywood, it would bulge out, just as a hernia in a man’s groin bulges due to weakened abdominal wall tissues.
Think of Keratoconus as a hernia in your cornea. Your cornea is also thinner than normal and that’s the cause of the bulge. This leads to increased irregular astigmatism (misshapen cornea) and steepening of the cornea, which cannot be easily corrected with standard contacts and glasses. This is the reason why your vision is blurrier than it was in the past. Vision loss from Keratoconus ranges from mild to very server loss. No two corneas of Keratoconus are exactly the same.
New research shows Keratoconus is much more common than in past. Years ago Keratoconus occurred in 1 in 2000 people, now it is 1 in 500, a 400% increase. No one is sure why there was been an increase in Keratoconus, but this is concerning.
Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism in the early stages of keratoconus.
As the disorder progresses and the cornea continues to thin and change shape, rigid gas permeable (RGP) contact lenses can be prescribed. The contact lenses must be carefully fitted, and frequent checkups and lens changes may be needed to achieve and maintain adequate vision.
It is common to develop intolerance to RGP (rigid gas permeable) contact lenses characterized by foreign body sensations, light sensitivity, irritation, and discomfort. If RGP contacts are not properly fit, it can cause corneal scarring occurs in more advanced cases and further reduced vision.
Historically a corneal transplant (penetrating keratoplasty) was the only option available to advanced Keratoconus patients. Today there are many modern treatments that are less invasive, provide quicker recovery, reverse some of the vision loss, and assist with stopping the progressive degeneration of vision from this condition. These treatments include Cornea Collagen Crosslinking with Riboflavin (Holcomb C3R®/CXL), Intacs®, Conductive Keratoplasty (CK), and Phakic IntraOcular Lenses (Visian ICL/Verisyse).