Laser Assisted in Situ Keratomileusis Combined With Corneal CXL in Eyes With Potentially Elevated Risk of Corneal Ectasia
Purpose
Concerns about corneal ectasia after laser in situ keratomileusis (LASIK) have prompted potentially overly stringent restrictions of patient eligibility. This pilot analysis was performed to evaluate combining LASIK with corneal cross-linking (CXL), a procedure that augments corneal strength, in eyes with theoretically increased risk of ectasia.
Methods
Nonrandomized, prospective study of 32 eyes (17 patients) thought to have increased risk for corneal ectasia. Risk factors included corneal thickness of 500µm or less, subtle irregular astigmatism on corneal tomography/topography, age 18-25 years, or high myopia (greater than 7 diopters (D)). Patients received wavefront-optimized LASIK with CXL performed prior to repositioning of the corneal flap. Visual and refractive outcomes as well as keratometric and topographic measurements were evaluated preoperatively and at 1, 3, 6, and 12 months postoperatively. Patients with incomplete follow-up were analyzed up to the last study visit.
Results
All eyes (100%) had uncorrected visual acuity (UCVA) of at least 20/40 at latest follow-up; 93.5% were 20/30 or better; 83.9% were 20/25 or better. Mean LogMAR UCVA improved from 1.39 +/- 0.47 to 0.10 +/- 0.19 (n=32) at 1 month, 0.08 +/- 0.13 (n=24) at 6 months, and 0.08 +/- 0.11 (n=16) at 12 months. Preoperative mean spherical equivalent refraction was -6.36 +/- 3.84D and improved to -0.074 +/- 0.62D (n=32) at 1 month, -0.115 +/- 0.55D (n=24) at 6 months, and -0.125 +/- 0.47D (n=16) at 12 months. No enhancements were performed.
Conclusion
In eyes with potentially increased risk for corneal ectasia, LASIK with CXL, using a proprietary CXL system, appears to be safe and effective. This combination may permit patients previously considered borderline candidates for excimer vision correction to be treated more safely than in the past.