SCLERAL LENSES FOR RADIAL #KERATOTOMY Radial keratotomy (RK) was the first popularized corneal refractive surgery for the correction of #myopia. During the RK procedure, partial-thickness incisions are cut into the #cornea in a radial pattern, which results in #corneal flattening. At its peak, approximately 250,000 RK procedures were performed annually in the United States (McDonald, 2011). Ten-year results from the Prospective Evaluation of Radial Keratotomy (PERK) study showed that of the 310 bilateral cases, 70% of patients reported not needing distance correction with glasses or contact lenses (Waring et al, 1994). However, many patients who have undergone RK become #hyperopic; the PERK study stated that the #refractiveerror of 43% of eyes changed in the hyperopic direction by 1.00D or more. Clinically, we know that some patients also have diurnal refractive fluctuations and #cornealirregularity. Contact Lens Challenges Depending on the degree of flattening, post-RK #corneas are significantly oblate. This can lead to failure when attempting to fit molded frequent-replacement soft #contactlenses that are designed for prolate #eyes. Corneal GP lenses are an option, but failure to precisely match to the surface profile will lead to failure. #Sclerallenses can provide a centered, stabilized fit by vaulting the oblate #cornealsurface. A reverse geometry design provides even corneal clearance. Paracentral areas of #ectasia can increase the complexity of obtaining limbus-to-limbus vault. Case in Point A 58-year-old patient who underwent eight-cut #RKsurgery in 1995 needed a #sclerallens refit after recent #cataract surgery for his right eye. A corneal elevation map of his right eye showed central flattening, with a paracentral inferior temporal area of ectasia. Read further at: https://www.clspectrum.com/issues/2019/november-2019/the-scleral-lens-vault By GREGORY W. DENAEYER, OD Another reason why scleral, cornea independent IOP is important. Ref https://tonometerdiaton.com #tonometry #tonometer #diaton #glaucoma #keratoconus #dryeye #dryeyes #ophthalmologist #ophthalmology #optometry #optometrist #eyecare #vision #eyesurgeon https://www.instagram.com/p/B5V5uJOB389/?igshid=5tucf49vw0il
