Dec 18, 2012 corneal ectasia following lasik surgery causes changes in the shape of the cornea and can lead to decreased vision. Comparison of corneal shape changes and aberrations. Decreasing vision after laserassisted insitu keratomileusis lasik history of present illness. It is more likely to occur following lasik, radial keratotomy rk, or astigmatic keratotomy ak surgery. Mcdonald even though prk poses a significantly lower risk of corneal ectasia than does lasik, some corneas are too thin to undergo either procedure, according. The peripheral cornea normally shows significant thickening from the central cornea. Known risk factors for post lasik corneal ectasia in miami. Lasik leads to significant and permanent biomechanical weakening of the cornea, which may lead to a sightrobbing complication known as postlasik corneal ectasia.
Postlasik visual quality with a corneoscleral contact lens. The authors have no proprietary or commercial interest in any materials discussed in this article. The geometry of this new kind of design is significantly flatter in the center than in the periphery its called reversegeometry, and is suited to the corneal geometry found in post lasik patients special measuring instruments are recommended to determine exact pointtopoint measurements of the postoperative anterior corneal surface. Although few patients with normal corneal topography develop postlasik ectasia, this surprise complication remains one of the most feared in laser refractive surgery, thanks to its potential to cause visual catastrophe. Partial flap avulsion following refractive surgery second, it captures the stretching of the surface in corneal ectasia and the stretched surface area increases in proportion to the mean curvature value. Intracorneal ring segment implantation is a useful option for the treatment of comalike aberrations and astigmatism in post lasik corneal ectasia. Intraoperative and postoperative complications of lasik. Granular corneal dystrophy type 2 and lasik recent case studies have indicated that exacerbation or onset of symptoms in those with gcd2 can occur with lasik surgery. International journal of keratoconus and ectatic corneal diseases, septemberdecember 2014. A special gas permeable contact or scleral lens will be needed to restore lost vision. Easy calculation evaluates postlasik ectasia risk american. Collagen crosslinking cxl, gp lenses, scleral lenses, and hybrid lenses have been shown to be an effective treatment for keratoconus and post lasik ectasia. A medline search for lasik and ectasia yielded 21 relevant articles published before may 2003 n 86 eyes, 59 patients.
Front and back corneal measurements improve the accuracy of calculations. The exact risk for post lasik ectasia is unknown and difficult to estimate, given advances in lasik technology and treatment protocols. Corneal ectasia definition of corneal ectasia by medical. High order aberration outcomes of corneal collagen. A new type of corneal refractive surgery, smile, which has less impact on corneal nerves, induces less postoperative dry eye, supporting the association between. A lasik associated corneal epithelial defect is a potentially significant complication that may result in suboptimal visual results.
Corneal ectasia is a severe complication occurring after lasik surgery. Keratoconus and corneal ectasia after lasik request pdf. Studies suggest it may occur in roughly one of every 2,000 lasik procedures. Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory, eye disorders characterised by bilateral thinning of the central, paracentral, or peripheral cornea. William trattler, director of cornea at the center for excellence in eye care in miami, florida. The two patients were treated by intrastromal corneal ring segments keraring and intacs sk for each patient to correct postlasik keratoectasia. Lasik reshapes the cornea, the eyes outermost layer, to bend light rays to focus on.
Characteristics of corneal ectasia after lasik for myopia. In this episode of a state of sight, isaac porter, md explains postlasik. Late onset corneal ectasia after lasik surgery sciencedirect. Ectatic corneas are both a contraindication and an occasional consequence of. In an attempt to clarify some of the issues surrounding postlasik ectasia, a committee of cornea and refractive surgeons assembled by the international society of refractive surgery american academy of ophthalmology and the american society of cataract and refractive surgery issued a consensus report in november 2005. New research expands on what we know about corneal changes after lasik and epi lasik, and even about the natural cornea itself. This article discusses the etiology, management, and prevention of this clinical challenge. Department of ophthalmology, university of toronto summary corneal ectasia is a serious complication of laser in situ keratomileusis lasik. Corneal crosslinking for keratectasia after laser in situ keratomileusis. The appearance and progression of post lasik ectasia are similar to a degenerative disease of the cornea called keratoconus.
Ectasia after lasik american academy of ophthalmology. Postlasik dry eye is one of the most common postoperative complications and has been reported to occur in approximately 50% of patients. Risk factors for ectasia after lasik include irregular preop corneal astigmatism and thin post op corneal thickness under the flap. Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia. Treatment of keratoectasia after lasik by intrastromal. Laser assisted in situ keratomileusis lasik a procedure using an excimer laser to remove tissue from within the middle layer stroma of the cornea after the. Pallikaris prelasik to postlasik 3, 6, and 9month corneal topographic map of a left eye, demonstrating focal inferior steepening. The cornea is too thin from the amount of corneal tissue that was removed with the laser procedure or a prior corneal disease and begins to protrude forward. Internal pressure from within the eye can cause expansion or distension of the cornea.
A diagnostic trial set was used in the fitting process. Postlasik granular corneal dystrophy university of iowa. Treating post lasik ectasia with corneal crosslinking by enette ngoei eyeworld contributing editor dr. Cornea understanding the post surgical cornea by matt young eyeworld contributing editor curvature map comparison of pentacam eye scanner source. Corneal ectasia induced by laser in situ keratomileusis. Dec 05, 2011 the cases presented, herewith, had late onset postlasik ectasia despite normal preop corneal topography, calculated residual corneal stromal bed thickness of more than 250. Therefore, a magd cscl was fitted and monitored according to standardized fitting methodology. Managing corneal ectasia prior to keratoplasty oculus pentacam. Post lasik ectasia treated with intrastromal corneal ring segments and corneal crosslinking kay lam, md, dan b. Laserverfahren wie lasik oder prk, astigmatische keratotomie oder. Laser vision correction lvc is the most popular elective medical procedure done in the united states, and its most feared complication is the.
In an apparent attempt to hide the truth about post lasik ectasia, lasik surgeons may deliberately misdiagnose post lasik corneal ectasia as post lasik keratoconus. High order aberration outcomes of corneal collagen crosslinking in eyes with keratoconus and post lasik ectasia. Eyeworld treating postlasik ectasia with corneal crosslinking. The medical literature contains reports of late onset ectasia occuring several years after lasik.
Corneal collagen crosslinking in postlasik keratectasia. Corneal ectasia following lasik surgery causes changes in the shape of the cornea and can lead to decreased vision. Before corneal refractive surgery such as lasik, smile, and prk, people must be examined for possible risk factors such as keratoconus. Research at our center suggests that a peripheral usually inferior cornea that is not 20m thicker than the central pachymetry raises suspicion for forme fruste keratoconus or an increased risk of post lasik ectasia. Dr holzer is a faculty member of cataract, corneal and refractive surgery at the. To evaluate changes in corneal topography indices after corneal collagen crosslinking cxl in patients with keratoconus and corneal ectasia and. Mar 05, 2014 post refractive surgery ectasia is a loss of corneal integrity leading to corneal warpage that often resembles keratoconus. Corneal ectasia detected 32 months after lasik for correction of myopia and asymmetric astigmatism. Postoperative hoas were much lower after smile as compared to fslasik. Intracorneal ring segment implantation in corneas with post. Figure 1 corneal tomography and biomechanical display from the fellow non operated eye of a patient that developed ectasia after lasik with no recognized. Postoperative factors may play a role in the pathogenesis of postlasik corneal ectasia.
Ectasia after lasik, corneal postlasik ectasia a state. Post laser in situ keratomileusis lasik corneal ectasia is one of the most feared complications of refractive surgery. This 56yearold woman presented status post bilateral lasik for myopia at an outside institution. Thankfully, with the development of cxl, patients who are diagnosed with keratoconus or post lasik ectasia now have a safe and effective therapy that can stop the condition from worsening in 97% to 99% of cases with a single treatment. Why cataract and refractive surgeons need the pentacam why.
Thibos and hong 17 presented data on one eye measured with a hartmannshack aberrometer both before and on the day after lasik refractive surgery to. Eye freedom after lasik, the cornea has been made thinner. Risk factors in postlasik corneal ectasia article pdf available in journal of ophthalmology 20143. Unter dem oberbegriff refraktive chirurgie werden augenoperationen zusammengefasst.
One histopathologic study looked at 12 ectatic corneas after lasik that underwent corneal transplantation. Kommission refraktive chirurgie krc aad augenarztliche. To evaluate the risk factors for post laser in situ keratomileusis lasik ectasia. Keratoconus is a naturally occuring disorder of the cornea which usually affects both eyes and typically begins during puberty or late teen years. Post surgical ectasia is a condition resembling keratoconus but comes from a different origin. Corneal ectasia post lasik complication new treatment info.
Stoneciphers patient returned in 2007 for additional treatment but showed signs of keratoectasia source. They manifested unsatisfactory visual quality with their current contact lenses or glasses. Ocular aberrations before and after myopic corneal refractive. Optometric comanagement of refractive surgery american. The advent of refractive surgery allowed for great advances in the understanding. Post lasik ectasia was described first by seiler et al. Ectasia after lasik postlasik keratoconus corneal ectasia.
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