Corneal ectasia is an umbrella term that describes a bulging of the cornea: keratoconus and pellucid-marginal degeneration fall under this term. Ectasia usually occurs due to weakened structures, and in the case of LASIK, the cornea is reshaped by thinning the structure with laser. There is not an exact number for post-refractive corneal thickness to ensure permanent stability – there are guidelines that are followed to ensure the cornea is not too thin to begin with or a general lower post-surgical limit. However though, most cases of post-LASIK corneal ectasia take many years before any symptoms or signs arise.
Post-LASIK corneal ectasia can manifest multiple discomforting symptoms that are very similar to keratoconus. Ectasia causes blur, distortion, double vision due to an uneven corneal surface. Where the bulging of the cornea can cause dry eye due to the mechanical involvement of the lids to the protruding cornea. This blinking process will rub on the protruding cornea that can lead to symptoms and signs of dry eye.
Even though ecstatic side effects can impair vision and quality of life, there are non-surgical and surgical methods to help restore comfort and vision. Like keratoconus, early stages of ectasia can be treated with glasses and soft contact lenses, but as the ectasia advances, specialty contact lenses must be
prescribed. Intacs have been done for many ectatic eyes as well as corneal transplants if the ectasia is progressed enough. However, though, I believe a scleral lens will help with most of these side effects, especially restoration in quality of vision and aiding in comfort from severe dry eye. A scleral lens is
also a non-invasive method of treating Post-LASIK Ectasia.
The way a scleral lens works is to bathe the cornea in saline solution to provide therapy; fortunately, this has an added effect by providing a smooth optical surface for light to enter the eye straight and undistorted – which means a clearer image than without the lens. In the case of corneal ectasia, we can treat this similarly to keratoconus in that a scleral lens will provide a consistent smooth interface throughout the cornea to provide increased visual potential. The other treatment methods require invasive surgery. Intacs are round inserts placed in the area of corneal ectasia to try and smooth the irregular surface – many times cross-linking is used in conjunction with intacs. If the ectasia is advanced enough a corneal transplant will be considered.