Keratoconus: Think Outside the CONE
Keratoconus (Kerato means Cornea and Konus means cone shaped) is a genetically programmed condition where the normally round cornea (clear front window of the eye) thins and begins to bulge into a cone-like shape. This cone shape deflects light irregularly as it enters the eye on its way to the light-sensitive retina, causing distorted vision.
Now as you know from our previous article, the shape of this cornea determines your nearsightedness, farsightedness and astigmatism.
So, as the cornea due to keratoconus becomes more irregular in shape, it causes progressive nearsightedness and irregular astigmatism to develop, creating additional problems with distorted and blurred vision.
A common history among early keratoconus patients is changes in their eyeglass prescription every time they visit their eye care practitioner. This may affect one or both eyes and may affect more than one member in the family tree. Many patients may present with high astigmatism or an unusual refractive error that is just never corrected to perfect vision ie. “I just don’t see great despite my glasses and contact lenses”.
High suspicion is an important indicator to suggest further diagnostic testing to determine keratoconus and address the patient’s constantly “not so perfect” vision.
Our cornea is normally made up of collagen fibers and research has revealed that there is any imbalance of enzymes in keratoconus cornea which makes this collagen more susceptible to oxidative damage from free radicals causing them to weaken and bulge forward.
In the early forms of keratoconus, eyeglasses or contact lenses could help but as the disease progresses and the cornea thins and becomes increasingly more irregular in shape, glasses and regular soft contact lens designs no longer provide adequate vision correction.
New generation, custom designed contact lenses are used for keratoconus patients today. These could also include hybrid lenses, piggyback lenses, hard lenses and scleral lenses.
For more advanced cases, traditionally the treatment has been a corneal transplant. Given the invasive nature of this surgery, new modalities have been devised to rehabilitate these patients with less interventional technology like INTACS which are plastic micro-inserts placed into the cornea like a brace to bring the severe cone shape to a more normal shape and then be adapted with a contact lens to help patients see.
Recently, a new technology called collagen cross-linking has been available under clinical trials for cases of keratoconus wherein this procedure, often called CXL/CCL/C3R for short, strengthens the corneal collagen to halt bulging of the eye’s shape in keratoconus.
With introduction of collagen cross-linking, combination surgeries become a possibility wherein some early cases of keratoconus can also avail of laser vision surgery (not LASIK but LASIK-like laser vision surgery without making a flap) and then be cross-linked in a staged manner.
In summary then, instead of “Sentencing” advanced keratoconus patients to a lifetime of “Vision Imprisonment”, we can now offer them new generation technological advances in laser vision surgery, custom cataract surgery, Intacs surgery, ICL surgery including combination surgeries to a truly achievable goal of “Vision Freedom”.
Lets break the “Shackles” then of limited options and limited vision for Keratoconus patients by indeed “Thinking outside the CONE”.