Text Size. Contrast Dark on Light Light on Dark. What is Glaucoma? In This Section. The Importance of Corneal Thickness. Why is Corneal Thickness Important? Pachymetry - A Simple Test to Determine Corneal Thickness A pachymetry test is a simple, quick, painless test to measure the thickness of your cornea.
Who is at Risk for Glaucoma? Types of Glaucoma. Are You at Risk For Glaucoma? Have a Question? Please enter your question in the Search box below.
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Subscribe Browse the Gleams Archive ». In long-sightedness hyperopia the eyeball is too short for its refractive power. In short-sightedness myopia it is too long. They have sought to address this mismatch of refractive power to eyeball length. By reshaping the cornea and changing its refraction. However , difficulties arise with a thin cornea. Since treatment options become limited when there is less corneal tissue to work with.
Some refractive procedures are better suited than others for addressing thin corneas. Treatment suitability is also subject to other eligibility criteria.
Such as pre-existing corneal disease and even lifestyle factors. Choosing the appropriate candidates for each type of procedure is important for success. The least corneal thickness required for refractive surgery is dependent on the degree of refractive error for correction.
The higher the prescription, the more corneal tissue that needs removing. If too little residual corneal tissue is left after surgery, there is the risk of a condition known as keratectasia. This refers to warping and distortion of a structurally weakened cornea.
This already reduces the amount of tissue available for reshaping. PRK surgery circumvents this problem by removing the very top layer. Known as the epithelium. Leaving the rest of the corneal tissues available for sculpting by excimer laser. For some, corneal thickness and prescriptions exclude them even from PRK surgery.
But there are still other treatment options available. Such as, refractive surgery techniques that do not involve the typical laser reshaping of the cornea. Intraocular contact lenses , or implantable contact lenses ICL , involve an artificial lens made of biosynthetic materials inserted between the iris and the crystalline lens. The only disruption to the cornea is a small incision to position the intraocular contact lens inside the eye.
No corneal tissue is removed during this procedure. So there is no minimum corneal thickness requirement. Intraocular contact lenses are able to correct very high degrees of myopia, hyperopia, and astigmatism. For additional information with potential benefits, risks and complications please visit DiscoverICL. Vukich JA. Carracedo, G. Cacho-Babillo, I. Besharati, MR. European Journal of Ophthalmology. Comparison of tear secretion and tear film instability after photorefractive keratectomy and laser in situ keratomileusis.
Psolka, M. Kezirian, G. Phakic intraocular lens implantantion in United States military warfighters: A retrospective analysis of early clinical outcomes of the Visian ICL. J Refract Surg. What are thin corneas? LASIK With the similar-sounding LASEK procedure, eye drops loosen the cells on top of the cornea, the cells are scraped to the side, a laser is applied to reshape the cornea, cells are smoothed back on and a contact lens is placed on top to help the healing.
The Visian ICL Possibly one of the strongest choices for people with thin corneas is Visian Implantable Collamer Lenses, a procedure that uses a biocompatible, advanced lens rather than cutting away eye tissue. You should NOT have Visian ICL surgery if: Your doctor determines that the shape of your eye is not an appropriate fit for the Visian ICL You are pregnant or nursing You do not meet the minimum endothelial cell density for your age at the time of implantation as determined by your eye doctor Your vision is not stable as determined by your eye doctor Before considering Visian ICL surgery you should have a complete eye examination and talk with your eye care professional about Visian ICL surgery, especially the potential benefits, risks, and complications.
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