After LASIK, the flap never recovers normal tensile strength. LASIK flaps may be accidentally dislodged or surgically re-lifted indefinitely. In 2005, researchers at Emory Eye Center, Emory University School of Medicine published their study of human eye bank corneas, which demonstrates the strength of the post-LASIK cornea at the flap interface is only 2% of normal corneal tensile strength.(1)
Long-term weakness of the LASIK interface wound has been confirmed by numerous case studies of late flap dislocation. The FDA website warns that patients who participate in contact sports are not good candidates for LASIK.(2) The medical literature contains reports of flap dislocation occurring months or years after LASIK following trauma to the eye during routine activities.(3)
“Laser in situ keratomileusis is another surgery in which the flap is prone to traumatic dislocation because the interface does not seem to heal except at the edges.” Source: Canto, et al. Protective effect of LASIK flap in penetrating keratoplasty following blunt trauma. J Cataract Refract Surg. 2011 Dec;37(12):2211-3.
“Although LASIK remains the most popular refractive surgical procedure, it is becoming apparent that corneal surfaces, cut to create the midstromal flap during surgery, fail to fully reunite postoperatively; surgeons can simply peel back an anterior corneal flap several years later. Such patients… are at risk for progressive visual disability due to general corneal weakness that may progress to ectasia or even traumatic displacement of the insecure flap.” Source: Mi, et al. Adhesion of laser in situ keratomileusis-like flaps in the cornea: Effects of crosslinking, stromal fibroblasts, and cytokine treatment. J Cataract Refract Surg. 2011 Jan;37(1):166-72.
“Furthermore, if [LASIK] interface transparency is indicative of absent wound healing, one might expect that the interface remains a potential space and flap adhesion is impaired for the lifetime of the flap.” Source: Ursea R, Feng MT. Traumatic flap striae 6 years after LASIK: case report and literature review. J Refract Surg. 2010 Nov;26(11):899-905.
“A possible explanation for the presentation of delayed keratitis after LASIK is that creating the lamellar flap may induce a permanent portal in the corneal periphery for microorganisms to penetrate.” Source: Vieira, et al. Late-onset Infections After LASIK. J Refract Surg. 2008 Apr;24(4):411-3.
“The corneal flap can be easily displaced following trauma many months after LASIK.” Source: Ramírez, et al. Traumatic flap dislocation 4 years after LASIK due to air bag injury.”J Refract Surg. 2007 Sep;23(7):729-30.
“The LASIK flap once cut may contribute little to the mechanical stability of the cornea and probably never completely adheres to the underlying stromal bed, with late traumatic flap displacement being reported as an infrequent complication.” Source: O’Brart, et al. Laser epithelial keratomileusis for the correction of hyperopia using a 7.0-mm optical zone with the Schwind ESIRIS laser. J Refract Surg. 2007 Apr;23(4):343-54.
“Our report, as well as the related literature, indicates that the healing of the flap is incomplete even 6 years after LASIK surgery.” Source: Landau, et al. Traumatic corneal flap dislocation one to six years after LASIK in nine eyes with a favorable outcome. J Refract Surg. 2006 Nov;22(9):884-9.
“Although ocular trauma with corneal laceration can occur, we report that the lamellar flap is still susceptible to ocular trauma 7 years after LASIK. Informed consent should include discussion of long-term flap complications and patients should be advised to protect their eyes after LASIK, especially during high risk activities.” Source: Jin GJ, Merkley KH. Laceration and partial dislocation of LASIK flaps 7 and 4 years postoperatively with 20/20 visual acuity after repair. J Refract Surg. 2006 Nov;22(9):904-5.
“The fact that this potential plane can be disrupted many years after LASIK (7 years after the initial surgery in patient 1) indicates that corneal integrity is compromised by the surgical procedure and takes a long time, if ever, to restore.” Source: Cheng, et al. Late Traumatic Flap Dislocations After LASIK. J Refract Surg Vol 22, May 2006.
“Another aspect of LASIK surgery is that during this procedure, a corneal flap is made, which will create lifelong lamellar corneal potential space.” Source: Galal, et al. Interface corneal edema secondary to steroid-induced elevation of intraocular pressure simulating diffuse lamellar keratitis. J Refract Surg. 2006 May;22(5):441-7.
“However, one aspect still in discussion is the wound-healing process in the created interface that leads to an easily removable flap even years after treatment.” Source: Priglinger, et al. Immunohistochemical Findings After LASIK Confirm In Vitro LASIK Model. Cornea, Volume 25(3), April 2006, pp 331-335
“Corneal stromal LASIK wounds were found to heal weaker than normal because these structures were not regenerated during the healing response. Moreover, the central and paracentral stromal LASIK wounds were found to heal by producing a hypocellular primitive stromal scar that is very weak in tensile strength, averaging 2.4% of normal, and displays no evidence of remodeling over time in specimens out to 6.5 years after surgery.” Source: Schmack, et al. Cohesive tensile strength of human LASIK wounds with histologic, ultrastructural, and clinical correlations. J Refract Surg. 2005 Sep-Oct;21(5):433-45.
“However, this case illustrates that even 4 years following the procedure, the lamellar flap remains an inherently weakened area of the eye, susceptible to traumatic disruption.” Source: Nilforoushan, et al. Traumatic flap dislocation 4 years after laser in situ keratomileusis. J Cataract Refract Surg. 2005 Aug;31(8):1664-5.