The Art and Science of Managing Post-LASIK Keratectasia
When to consider contact lenses versus surgical intervention for the best patient outcomes.
Jessica O. Yu, OD, FAAO, FSLS
Modern Optometry 
Laser-assisted in situ keratomileusis (LASIK) is one of the most commonly performed refractive surgeries that provides permanent vision correction.1 This procedure generally has an excellent safety profile and is highly successful, but a small percentage of patients experience complications postoperatively.1-3 The alteration and compromise of the biomechanical strength of the cornea can lead to instability and the development of keratectasia, a rare but serious complication that results in a high degree of myopic astigmatism, which leads to a decrease in corrected distance visual acuity.2 This article discusses the management of post-LASIK keratectasia, specifically with contact lenses. CORNEAL ECTASIA REFRESHER Preoperative risk factors for corneal ectasia include abnormal corneal topography, low residual stromal bed thickness, younger patient age, low preoperative corneal thickness, and treated high myopia.3-5 Despite advances in pre-screening strategies and modern surgical technology, the estimated incidence of post-LASIK ectasia was reported to be 0.033% in 2018.4,6,7 This progressive, structural deformation of the cornea causes optical refractive instability and subsequent loss of BCVA.3,6,8 With highly variable corneal presentations, coupled with the difficulty and emotional frustration patients experience with habitual activities, the management of post-LASIK ectasia can be challenging on many levels. On topography, postoperative ectasias present similarly to keratoconus, showing asymmetric, inferior corneal steepening associated with stromal thinning (Figure 1).9,10 Moreover, “multifocal” corneas, central islands, and irregular or decentered ablation profiles can be noted. Other clinical signs of ectasia include significant changes in refractive error, progressive increases in irregular astigmatism, central haze, and anterior and posterior corneal steepening.1,6,9-12 Figure 1. Topography of prolate post-LASIK cornea, previously with moderate hyperopia (+2.25 D). There are multiple potential causes for suboptimal visual outcomes with post-LASIK corneal ectasia, including residual refractive error, high or irregular astigmatism, decentration of the optical zone, flap complications, and corneal haze.1,3,6,11,13 Patients subjectively experience an array of visual symptoms, such as halos, starbursts, double vision, monocular polyopia, glare and ghosting, or “smeared” vision.1,3,11-15 Poor night vision is among the most common symptoms described by patients, with varying degrees of distortion and loss of contrast.14,16 Some patients also present with complications due to dryness or higher-order aberrations (HOAs), which may be caused by flap complications or irregular ablations.12,14 These symptoms all lead to significant subjective dissatisfaction and lifestyle difficulties. TREATMENT OPTIONS Surgical Considerations Various surgically oriented interventions can be considered for the treatment of post-LASIK ectasia, especially when progression is noted. Corneal collagen crosslinking is the preferred procedure when the primary goal is to halt the ectatic progression by stabilizing the collagen framework and improving the biomechanical strength of the cornea.4,10 Moreover, the prevalence of corneal collagen crosslinking combined with wavefront or topography-guided photorefractive keratectomy has gained widespread acceptance to help modulate and stabilize the ectatic cornea and improve visual acuity.4,6 Other surgical treatment options include implantation of intracorneal ring segments to decrease ectasia, corneal tissue addition for keratoplasty (CTAK, CorneaGen), and lamellar keratoplasty.4,8,9,17 When retreatment is possible, customized ablations and combination strategies have proven effective.16 However, when further surgical intervention may no longer be desired or deemed a clinical possibility, contact lenses, specifically rigid gas permeable (RGP) lenses, can offer significant therapeutic vision rehabilitation.15 Postoperative Contact Lens Fitting In some cases, the goal of fitting postoperative corneas is not only to improve BCVA, but also to reduce HOAs under scotopic and mesopic conditions, where low luminance and nighttime conditions present extraordinary subjective challenges. The alterations in corneal architecture after a LASIK procedure present intricate complexities, as different factors dictate the fitting approach. The topography, refractive error, contact lens tolerance, and patient mindset must be considered.
