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Keratoconus is defined as a progressive non-inflammatory eye condition in which the normally round cornea begins to thin and bulge into a cone-like shape. The cornea is the clear window of the eye and is responsible for refracting most of the light coming into the eye. This cone shape actually deflects light as it enters the eye, causing distorted vision. This results in significant visual impairment and can severely affect the way we see the world, making simple tasks like driving, watching TV or reading a book challenging.
The key to minimizing the visual impact of keratoconus is early detection and proper management. Extensive ongoing research along with advanced technology have paved the way for new treatment options, opening the door to a clearer more comfortable world for people with keratoconus. Dr. Yecheskel has worked extensively within the ophthalmologic framework of cutting edge treatment for keratoconus. Accurate and early detection is now a crucial step toward successful management of the disease, in terms of minimizing its progression as well as creating long term optimal visual acuity.
In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually first appear in the late teens and early twenties. As the cornea becomes more irregular in shape, it causes progressive nearsightedness and irregular astigmatism to develop, creating additional problems with distorted and blurred vision. Glare and light sensitivity also may occur. Keratoconus may progress for 10-20 years and then slow or stabilize. Each eye may be affected differently.
New research suggests the weakening of the corneal tissue that leads to keratoconus may be due to an imbalance of enzymes within the cornea. This imbalance makes the cornea more susceptible to oxidative damage from compounds called free radicals, causing it to weaken and bulge forward. Risk factors for oxidative damage and weakening of the cornea include a genetic predisposition, explaining why keratoconus often affects more than one member of the same family. Keratoconus is also associated with overexposure to ultraviolet rays from the sun, excessive eye rubbing, a history of poorly fitted contact lenses and chronic eye irritation.
There are a variety of strategies to optimally manage keratoconus:
Custom Designed Contact Lenses
Custom Soft Contact Lenses
Custom soft contact lenses are specially designed to correct mild-to-moderate keratoconus. These lenses are made-to-order based on detailed measurements of the person's keratoconic eye(s) and may be more comfortable than gas permeable lenses (GPs) or hybrid contact lenses for some wearers.
Gas Permeable Contact Lenses
Their rigid lens material enables GP lenses to vault over the cornea, replacing its irregular shape with a smooth, uniform refracting surface to improve vision.
Hybrid Contact Lenses
Hybrid contacts specially designed for keratoconus provide the crisp optics of a gas permeable contact lens and wearing comfort that rivals that of soft lenses.
Scleral and Semi-Scleral Lenses
These are large-diameter gas permeable contacts that vaults over the irregularly shaped cornea. These lenses don't apply pressure to the eye's cone-shaped surface for a more comfortable and stable fit.
These surgically applied corneal inserts manufactured by Addition Technology received FDA approval for treating keratoconus in August 2004. The tiny plastic inserts are placed just under the eye's surface in the periphery of the cornea and help re-shape the cornea for clearer vision
This procedure, often called CXL for short, strengthens corneal tissue to halt bulging of the eye's surface in keratoconus. There are several clinical trials of corneal crosslinking in progress in the United States (where the procedure is not yet FDA-approved). The procedure is available in other countries. Corneal crosslinking may significantly reduce the need for corneal transplants amount keratoconus patients.
Topography-Guided Conductive Keratoplasty
This treatment uses energy from radio waves, applied with a small probe at several points in the periphery of the cornea to reshape the eye's front surface. A topographic "map" created by computer imaging of the eye's surface helps create individualized treatment plans.
The last remedy to be considered may be a cornea transplant, also called a penetrating keratoplasty (PK or PKP). Even after a transplant, you most likely will need glasses or contact lenses for clear vision.