Under-flap stromal bed CXL for early post-LASIK ectasia: a novel treatment technique

Abstract

PurposeCollagen cross-linking (CXL) for post-laser-assisted in situ keratomileusis (LASIK) ectasia (PLE) is traditionally performed either epi-on or epi-off on the corneal surface. This study describes a novel technique in treating early PLE with under-flap CXL (ufCXL) to the stromal bed and reports on 6-month outcomes.Patients and methodsCase series of seven patients (eight eyes) with topography-diagnosed early PLE treated with ufCXL. Inclusion criteria were early, mild PLE defined as new-onset postoperative manifest refraction cylinder ≤1.50 D, with new topographic inferior steepening consistent with ectasia, uncorrected distance visual acuity (UDVA) of 20/40 or better, and corrected distance visual acuity (CDVA) of 20/25 or better. Existing LASIK flap was lifted, riboflavin was applied directly to the stromal bed, flap was repositioned, and 18 mW/cm2 ultraviolet light was applied for 3 minutes to the corneal surface. Post-ufCXL manifest refraction, UDVA and CDVA, corneal cylinder, Kmax, and corneal irregularity index were compared with pre-ufCXL measurements.ResultsPatients had a pre-ufCXL sphere of 0.09±0.48 D and cylinder of −0.78±0.49 D. At 6 months, post-ufCXL sphere (0.06±0.8 D; P=0.89) and cylinder (−1.09±0.76 D, P=0.26) were unchanged. Cumulative post-ufCXL UDVA was unchanged, achieving 20/20, 20/30, and 20/40 in 25%, 88%, and 88%, respectively, compared with 13%, 63%, and 88% pre-ufCXL (P=0.68). Post-ufCXL CDVA was unchanged (P=0.93) with a gain of one line in two eyes, a loss of one line in one eye, and five eyes unchanged. The efficacy index (P=0.76), safety index (P=0.89), Kmax (P=0.94), and corneal irregularity index (P=0.73) were also unchanged.ConclusionPreliminary results with ufCXL for early PLE are promising, demonstrating maintenance of visual accuracy, efficacy, safety, Kmax, and cylinder, with much quicker recovery times than surface CXL.

Refractive, visual, and subjective quality of vision outcomes for very high myopia LASIK from − 10.00 to − 13.50 diopters

“…Longer term follow-up would be needed to further monitor for ectasia. These eyes, possibly at higher risk, should have more frequent sequential follow-up visits to monitor for early signs of post-LASIK ectasia, that can be treated with under-flap corneal collagen cross linking with the potential to preserve vision [41].…”

AstigMATIC: an automatic tool for standard astigmatism vector analysis

“…AstigMATIC can be used to automatically produce the standard graphs for reporting outcomes for astigmatism correction, based on the Alpins Method, that are recommended by refractive surgery and ophthalmology journals [ 10 , 12 – 15 ]. The tool was developed for teaching and academic research purposes in the context of laser refractive surgery, but its use can be extended to analyze any corneal and intraocular refractive surgery outcomes [ 16 – 25 ]. AstigMATIC can be used providing that the user(s) cite the current manuscript when including results generated from AstigMATIC in any publication, presentation, or other public communication, whether peer-reviewed or non-peer-reviewed.…”

“…These four graphs allow a more detailed understanding of astigmatism outcomes pre- to post-surgery, and can better identify precision in surgical results [ 10 , 12 – 15 ]. The Alpins Method lends itself to any ocular procedure where astigmatism outcomes need to be thoroughly assessed [ 10 ], such as PRK, LASIK, LASEK, SMILE, incisional keratotomy, collagen cross-linking, intracorneal ring segments, as well as lens-based procedures such as Phakic IOL, cataract surgery and refractive lens exchange with multifocal IOL and/or Toric IOL, as well as the various modified surgical techniques or procedures to treat various RS complications that exist today [ 16 – 25 ].…”

Post Laser-assisted in situ Keratomileusis Ectasia: A Systematic Review

“…44 In a retrospective case series study, Yildirim 47 The under-flap technique involves lifting the existing LASIK flap, followed by ultrasound pachymetry performed on the stromal bed. A sponge soaked with 0.25% riboflavin solution is placed on the stromal bed for 3 minutes.…”