Ectasia after laser in situ keratomileusis

Binder, Perry S.

doi:10.1016/j.jcrs.2003.10.012

Cited by 226 publications

(169 citation statements)

References 72 publications

Supporting

Mentioning

154

Contrasting

Unclassified

Order By: Relevance

“…31,32 Similarly, with the development of refractive surgery procedures, CCT values are of enormous importance during the preoperative evaluation of the patients, the decision whether or not to perform surgery, the type of recommended procedure, and rate of postoperative complications. 33,34 Mixed populations are ideal for comparing CCT measurements in different ethnic groups under the supervision of the same investigators and the use of the same pachymeters. With people immigrating to Israel from almost all countries around the world, Israel demography provides an excellent opportunity to evaluate CCT in populations of different origin, including North Africa.…”

Section: 18mentioning

confidence: 99%

Central corneal thickness and its relationship to the patient's origin

Lifshitz

Levy

Rosen

et al. 2005

Eye

View full text Add to dashboard Cite

Objectives To report central corneal thickness (CCT) measurements on patients requesting refractive surgery and to search for possible associations between CCT and patient's origin, age, sex, and preoperative data. Patients of North African origin were significantly older than patients of other origins (P ¼ 0.028). No differences were found when comparing for sex, intraocular pressure, refractive status, and keratometry. When multivariate analysis was performed patient's origin was the only independently associated factor associated with CCT. Conclusions This is the first work in reporting lower CCT in people of North African origin examined in a refractive surgery centre. Studies from similar populations are needed to confirm our results.

show abstract

Section: 18mentioning

confidence: 99%

Central corneal thickness and its relationship to the patient's origin

Lifshitz

Levy

Rosen

et al. 2005

Eye

View full text Add to dashboard Cite

show abstract

“…In some cases, preexisting forme fruste keratoconus was documented. 17,18 Other cases could be caused by a mechanical collapse of the corneal structure because of thinning induced by surgery. 18 Extracellular matrix (ECM) changes and increased matrix metalloproteinases (MMPs) 19 may also be contributing factors.…”

mentioning

confidence: 99%

Alterations of Extracellular Matrix Components and Proteinases in Human Corneal Buttons With INTACS for Post-Laser In Situ Keratomileusis Keratectasia and Keratoconus

Maguen¹,

Rabinowitz²,

Regev³

et al. 2008

Cornea

View full text Add to dashboard Cite

Purpose-To perform an immunohistochemical evaluation of corneas with INTACS for post-laser in situ keratomileusis (LASIK) keratectasia and keratoconus, obtained after corneal transplantation.Methods-Corneas from 1 patient with INTACS for post-LASIK keratectasia and 2 patients with INTACS for keratoconus were obtained within 3 hours after penetrating keratoplasty, and cryostat sections were analyzed by immunostaining for 35 extracellular matrix (ECM) components and proteinases.Results-In the stroma of all corneas next to an INTACS implant, ECM components typically associated with fibrosis were observed. These included tenascin-C, fibrillin-1, and types III, IV (α1/ α2 chains), and XIV collagen. Also, significant deposition of perlecan, nidogen-2, and cellular fibronectin was revealed in the same locations. The keratoconus cases displayed typical Bowman layer breaks and subepithelial fibrosis with deposition of various ECM components. In all cases, some keratocytes around INTACS were positive for specific proteinases associated with stromal remodeling, including cathepsins F and H, matrix metalloproteinase (MMP)-1, MMP-3, and MMP-10. Staining for MMP-7 was variable; MMP-2 and MMP-9 were mostly negative. Patterns of type IV collagen α3, α4, and α6 chains; types VI and VIII collagen;α4, α5,β1, β2, and γ1 laminin chains; vitronectin; thrombospondin-1; urokinase; EMMPRIN; and cathepsins B and L were unchanged around INTACS in all 3 cases compared with normal. Recently, INTACS has acquired new interest as an alternative treatment of keratoconus. [5][6][7][8][9][10] The rationale is that INTACS not only flattens the central cornea but also corrects some of the astigmatic component. The corneal profile becomes more symmetrical, usually allowing better correction with glasses and contact lenses. Given that, for these patients, the alternative would be penetrating keratoplasty, INTACS may delay the need for this option. 10,11 Midstromal semicircular channels for INTACS ring insertion are created by a mechanical system with a blunt spiral device. 1,12,13 Despite the streamlined mechanistic procedure, attempts were made to improve control over the depth and shape of the channels. A femtosecond laser mounted on a delivery system capable of creating an intrastromal pattern of virtually any shape was recently used to create channels for INTACS insertion. 10 This method may be technically easier and more precise, reflecting better final outcomes. Conclusions-AbnormalKeratectasia is a rare but serious complication of laser vision correction of any refractive errors. It occurs mostly after LASIK but was also described after surface excimer laser ablation (photorefractive keratectomy). 14-16 It involves severe refractive changes mostly occurring several years after the surgery, which are caused by thinning and sagging of the corneal profile, similar to keratoconus.The etiology of this complication remains uncertain. In some cases, preexisting forme fruste keratoconus was documented. 17,18 Other cases could be caused by a me...

show abstract

“…Enhanced refractive surgery screening goes beyond corneal tomography and should include corneal biomechanics assessment. The main objective is to identify refractive candidates with an increased biomechanical susceptibility to post-LASIK ectasia (1,10,11) . Refractive surgery results are also influenced by the biomechanical response in changing the corneal shape (12,13) .…”

Section: Introductionmentioning

confidence: 99%