2
|
Wallerstein A, Gauvin M, Rocha G, Sison R, Korban S, Cohen M. Three-Year Outcomes of Under-flap Stromal Bed CXL for Early Post-LASIK Ectasia. J Refract Surg 2022; 38:511-519. [PMID: 35946998 DOI: 10.3928/1081597x-20220713-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the 36-month clinical outcomes of under-flap stromal bed CXL (ufCXL) and report on its ability to stabilize post-laser in situ keratomileusis (LASIK) ectasia. METHODS This case series included 20 eyes with diagnosed early post-LASIK ectasia treated with ufCXL. Inclusion criteria were early, mild post-LASIK ectasia, defined as new-onset postoperative manifest refraction cylinder of 1.50 diopters (D) or less, with new topographic inferior steepening consistent with ectasia, uncorrected distance visual acuity of 20/40 or better, and corrected distance visual acuity of 20/25 or better. The existing LASIK flap was lifted, 0.25% isotonic riboflavin was applied directly to the stromal bed, the flap was repositioned, and 18 mW/cm2 ultraviolet light was applied for 5 minutes to the corneal flap surface. Post-ufCXL ophthalmic data were compared to pre-ufCXL baseline measurements. RESULTS Visual outcomes were maintained pre-ufCXL to 36 months post-ufCXL, with preserved safety index (P = .6545), efficacy index (P = .4980), spherical equivalent accuracy (P = .1536), defocus equivalent accuracy (P = .1032), central corneal thickness (P = .5196), and corneal irregularity indices at 3 mm (P = .8548) and 5 mm (P = .3399). Refractive astigmatism significantly decreased from 0.83 to 0.55 D pre-ufCXL to post-ufCXL (P = .0439), as did maximum keratometry from 42.40 to 42.00 D pre-ufCXL to post-ufCXL (P = .0420). The ufCXL demarcation line depth was 336 ± 21 µm post-ufCXL, with normal endothelial cell density (2,574 ± 203 cells/mm2). Only 1 of 20 eyes showed evidence of progression of 1.00 D in maximum keratometry. CONCLUSIONS The ufCXL procedure shows promise in stabilizing early post-LASIK ectasia. Visual function, refractive astigmatism, maximum keratometry, and corneal irregularity indices were statistically maintained at 36 months postoperatively. [J Refract Surg. 2022;38(8):511-519.].
Collapse
|
3
|
Nasef MH, El Emam SY, Haleem TI, Shalaby WS, Allam WA. Visual and Topographic Outcomes of Corneal Collagen Cross Linking for Post LASIK Ectasia. Clin Ophthalmol 2022; 16:2025-2032. [PMID: 35757019 PMCID: PMC9231688 DOI: 10.2147/opth.s370033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/08/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To assess the topographic and visual outcomes of corneal cross-linking (CXL) for post-LASIK ectasia. Methods A retrospective case series of patients who had progressive post-LASIK ectasia, with at least 2 years of follow-up. They had epithelium-off CXL. Topographical and visual changes were recorded. Results The study included 21 eyes of 11 patients. At month 24, the final logMAR corrected distance visual acuity (CDVA) and spherical equivalent (SE) were stable compared to baseline (0.16, and −2.0 diopter (D), respectively). The final Kmean and Kmax were 42.5 and 47.4 D, respectively. Stability or improvement in CDVA, SE, and Kmax was seen in 17 eyes (81%). Significant corneal thinning was seen (438 vs 457 microns, p = 0.003). Thinning by 2% or more was seen in 12 eyes (57.1%). Failure of CXL was seen in 4 eyes (19%). No other ocular complications were seen. Conclusion CXL for post LASIK ectasia is a safe and effective modality. Despite corneal thinning, there was stability or improvement in topographic parameters and CDVA over the 2-year follow-up period.
Collapse
Affiliation(s)
- Mohamed H Nasef
- Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Gharbia, Egypt
- Correspondence: Mohamed H Nasef, Tanta University Ophthalmology Hospital, Tanta University Medical Campus, Al-Geish St, Tanta, Gharbia, 31527, Egypt, Tel +20 10 02826555, Email
| | - Sharif Y El Emam
- Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Gharbia, Egypt
| | - Tamer I Haleem
- Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Gharbia, Egypt
| | - Wesam S Shalaby
- Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Gharbia, Egypt
| | - Waleed A Allam
- Ophthalmology Department, Faculty of Medicine, Tanta University, Tanta, Gharbia, Egypt
| |
Collapse
|
4
|
Tian M, Zhang X, Jian W, Sun L, Shen Y, Zhou X. Long-Term Follow-Up of Accelerated Transepithelial Corneal Crosslinking for Post-LASIK Ectasia: A Pilot Prospective Observational Study. Front Bioeng Biotechnol 2022; 9:809262. [PMID: 35004659 PMCID: PMC8727765 DOI: 10.3389/fbioe.2021.809262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/06/2021] [Indexed: 11/22/2022] Open
Abstract
Background: Keratectasia after corneal refractive surgery is a rare but serious postoperative complication, and reports on accelerated transepithelial corneal crosslinking (ATE-CXL)-based treatment of patients with post-laser-assisted in situ keratomileusis (LASIK) ectasia are limited. Therefore, this study evaluated the long-term efficacy and safety of ATE-CXL for progressive post-LASIK ectasia. Methods: This prospective observational study was conducted at the Eye and ENT Hospital, Fudan University, Shanghai, China, and 25 eyes from 25 patients with post-LASIK ectasia undergoing ATE-CXL were examined. Clinical examinations were conducted preoperatively and postoperatively to assess parameters such as manifest refraction, corrected distance visual acuity (CDVA), endothelial cell density; keratometry, corneal thickness, posterior elevation and topometric indices were measured using Pentacam; sectoral pachymetry and epithelial thickness were evaluated using optical coherence tomography. A paired t-test, Wilcoxon rank-sum test, Kruskal-Wallis test, and repeated measures analysis of variance were used for statistical analysis. Results: Participants were examined for an average of 46 months. No severe complications occurred during or after ATE-CXL. CDVA improved from 0.25 ± 0.31 preoperatively to 0.15 ± 0.17 postoperatively (p = 0.011). Maximum keratometry decreased from 55.20 ± 8.33 D to 54.40 ± 7.98 D, with no statistical significance (p = 0.074), and the central corneal thickness increased from 414.92 ± 40.96 μm to 420.28 ± 44.78 μm (p = 0.047) at the final follow-up. Posterior elevation, pachymetry, and epithelial thickness remained stable (p > 0.05) throughout the follow-up. No significant differences were noted in topometric indices, except the central keratoconus index, which decreased significantly (p < 0.001) at the final follow-up. Conclusion: Improvements in CDVA and stabilization in corneal keratometry and posterior elevation after ATE-CXL were noted at the 46-months follow-up, demonstrating that ATE-CXL is a safe and effective treatment for progressive post-LASIK ectasia.
Collapse
Affiliation(s)
- Mi Tian
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Xiaoyu Zhang
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Weijun Jian
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Ling Sun
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yang Shen
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| |
Collapse
|
5
|
Brillouin microscopic depth-dependent analysis of corneal crosslinking performed over or under the LASIK flap. J Cataract Refract Surg 2021; 46:1543-1547. [PMID: 33149067 DOI: 10.1097/j.jcrs.0000000000000294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine the impact of corneal crosslinking (CXL) performed over the laser in situ keratomileusis (LASIK) flap using the Standard CXL (S-CXL) protocol or under the flap after flap lift (flap-CXL) on regional corneal stiffness using Brillouin microscopy. SETTING University of Southern California Keck School of Medicine, Los Angeles, California, and Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA. DESIGN Laboratory ex vivo experiment. METHODS After epithelium debridement, LASIK flaps were created on intact fresh porcine eyes with a mechanical microkeratome. Then, S-CXL (riboflavin applied to the corneal surface followed by 3 mW/cm ultraviolet exposure with the flap in place for 30 minutes) or flap-CXL (riboflavin applied to the stromal bed after reflecting the flap followed by the same ultraviolet A exposure with the flap replaced) was performed. Depth profile of stiffness variation and averaged elastic modulus of anterior, middle, and posterior stroma were determined by analyzing Brillouin maps. Each eye served as its own control. RESULTS The study was performed on 24 fresh porcine eyes. S-CXL had maximal stiffening impact in the anterior most corneal stroma within the LASIK flap (8.40 ± 0.04 GHz), whereas flap-CXL had lower maximal stiffening impact (8.22 ± 0.03 GHz) (P < .001) that occurred 249 ± 34 μm under the corneal surface. S-CXL increased longitudinal modulus by 6.69% (anterior), 0.48% (middle), and -0.91% (posterior) as compared with flap-CXL, which increased longitudinal modulus by 3.43% (anterior, P < .001), 1.23% (middle, P < .1), and -0.78% (posterior, P = .68). CONCLUSIONS The S-CXL technique generated significantly greater stiffening effect in the anterior cornea than a modified protocol with riboflavin administration under the flap (flap-CXL). Minimal stiffening occurred in the middle or posterior cornea with either protocol.
Collapse
|