Aim and objective: To evaluate the 3-year follow-up clinical outcomes obtained in corneal ectasia using Epi-ON corneal collagen cross-linking (CXL).
Materials and methods: This study is a retrospective study enrolling 46 eyes from 32 patients with progressive corneal ectasia and treated with Epi-ON CXL in the period from September 2012 to April 2016. Two groups were differentiated according to the type of corneal ectasia: ectasia post-LASIK group (EPL, 12 eyes) and primary ectasia group (34 eyes). Two different platforms were used for the surgical protocol: VEGA CBM X LINKER platform (CSO, Firenze, Italy) and KXL (Avedro, Waltham, Massachusetts, USA). Visual, refractive, and corneal tomographic outcomes were evaluated during a 3-year follow-up.
Results: A statistically significant improvement in the logMAR corrected distance visual acuity (CDVA) was observed in the whole sample (p <0.001) during the follow-up, with half of the sample improving one or more lines of CDVA. Likewise, only significant changes were detected in steepest keratometry (p <0.001), corneal astigmatism (p = 0.012), and index of height asymmetry (p = 0.021), with a trend to increase. Regarding the comparison between groups, more significant improvement in CDVA was found in the EPL group compared to the primary ectasia group (−0.07 ± 0.09 vs −0.15 ± 0.14, p = 0.028). Likewise, a significant trend to more corneal thinning was observed in primary ectasia group (p = 0.034).
Conclusion: Epi-ON CXL is efficacious for stabilizing the progression of primary and iatrogenic ectasias for most cases, with significant improvement of visual acuity associated.
Galvis V, Sherwin T, Tello A, et al. Keratoconus: an inflammatory disorder? Eye (Lond) 2015;29(7):843–859. DOI: 10.1038/eye.2015.63.
Balasubramanian SA, Pye D, Willcox M. Effects of eye rubbing on the levels of protease, protease activity and cytokines in thears: relevance in keratoconus. Clin Exp Optom 2013;96(2):214–218. DOI: 10.1111/cxo.12038.
Balasubramanian SA, Pye DC, Willcox MD. Are proteinases the reason for keratoconus? Curr Eye Res 2010;35(3):185–191. DOI: 10.3109/02713680903477824.
Lema I, Duran JA. Inflammatory molecules in the tears of patients with keratoconus. Ophthalmology 2005;112(4):654–659. DOI: 10.1016/j.ophtha.2004.11.050.
Hashemi H, Khabazkhoob M, Yazdani N, et al. The prevalence of keratoconus in a young population in Mashhad, Iran. Ophthalmic Physiol Opt 2014;34(5):519–527. DOI: 10.1111/opo.12147.
Hashemi H, Beiranvand A, Khabazkhoob M, et al. Prevalence of keratoconus in a population-based study in Sharoud. Cornea 2013;32(11):1441–1444. DOI: 10.1097/ICO.0b013e3182a0d014.
Hashemi H, Khabazkhoob M, Fotouhi A. Topographic keratoconus is not rare in an Iranian population: the Tehran Eye Study. Ophthalmic Epidemiol 2013;20(6):385–391. DOI: 10.3109/09286586.2013.848458.
Shneor E, Millodot M, Blumberg S, et al. Characteristics of 244 patients with keratoconus seen in an optometric contact lens practice. Clin Exp Optom 2013;96(2):219–224. DOI: 10.1111/cxo.12005.
Martínez-Abad A, Piñero DP. New perspectives on the detection and progression of keratoconus. J Cataract Refract Surg 2017;43(9): 1213–1227. DOI: 10.1016/j.jcrs.2017.07.021.
Andreassen TT, Simonsen AH, Oxlund H. Biomechanical properties of keratoconus and normal corneas. Exp Eye Res 1980;31(4):435–441. DOI: 10.1016/s0014-4835(80)80027-3.
Jeng BH, Farid M, Patel SV, et al. Corneal cross-linking for keratoconus: a look at the data, the food and drug administration, and the future. Ophthalmology 2016;123(11):2270–2272. DOI: 10.1016/j.ophtha.2016.08.006.
Spoerl E, Huhle M, Seiler T. Induction of cross-links in corneal tissue. Exp Eye Res 1998;66(1):97–103. DOI: 10.1006/exer.1997.0410.
Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135(5):620–627. DOI: 10.1016/s0002-9394(02) 02220-1.
Hamida Abdelkader SM, Fernández J, Rodríguez-Vallejo M, et al. Comparison of different methods of corneal collagen crosslinking: a systematic review. Semin Ophthalmol 2021;36(3):67–74. DOI: 10.1080/08820538.2021.1890784.
Martínez-Abad A, Piñero DP. Pellucid marginal degeneration: detection, discrimination from other corneal ectatic disorders and progression. Cont Lens Anterior Eye 2019;42(4):341–349. DOI: 10.1016/j.clae.2018.11.010.
Piñero DP, Alió JL, Barraquer RI, et al. Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism. J Cataract Refract Surg 2011;37(7):1291–1299. DOI: 10.1016/j.jcrs.2010.12.063.
Baiocchi S, Mazzotta C, Cerretani D, et al. Corneal crosslinking: riboflavin concentration in corneal stroma exposed with and without epithelium. J Cataract Refract Surg 2009;35(5):893-899. DOI: 10.1016/j.jcrs.2009.01.009.
Henriquez MA, Hernandez-Sahagun G, Camargo J, et al. Accelerated epi-on versus standard epi-off corneal collagen cross-linking for progressive keratoconus in pediatric patients: five years of follow-up. Cornea 2020;39(12):1493–1498. DOI: 10.1097/ICO.0000000000002463.
Eraslan M, Toker E, Cerman E, et al. Efficacy of epithelium-off and epithelium-on corneal collagen cross-linking in pediatric keratoconus. Eye Contact Lens 2017;43(3):155–161. DOI: 10.1097/ICL.0000000000000255.
Wollensak G, Aurich H, Wirbelauer C, et al. Significance of the riboflavin film in corneal collagen crosslinking. J Cataract Refract Surg 2010;36(1):114–120. DOI: 10.1016/j.jcrs.2009.07.044.
Wollensak G, Iomdina E. Long-term biomechanical properties of rabbit cornea after photodynamic collagen crosslinking. Acta Ophthalmol 2009;87(1):48–51. DOI: 10.1111/j.1755-3768.2008.01190.x.
Hill J, Liu C, Deardorff P, et al. Optimization of oxygen dynamics, UV-A delivery, and drug formulation for accelerated epi-on corneal crosslinking. Curr Eye Res 2020;45(4):450–458. DOI: 10.1080/02713683.2019.1669663.
Faramarzi A, Hassanpour K, Rahmani B, et al. Systemic supplemental oxygen therapy during accelerated corneal cross-linking for progressive keratoconus; a randomized clinical trial. J Cataract Refract Surg 2021;47(6):773–779. DOI: 10.1097/j.jcrs.0000000000000513.
Mazzotta C, Raiskup F, Hafezi F, et al. Long term results of accelerated 9 mW corneal crosslinking for early progressive keratoconus: the Siena Eye-Cross Study 2. Eye Vis (Lond) 2021;8(1):16. DOI: 10.1186/s40662-021-00240-8.
Zhang X, Sun L, Tian M, et al. Accelerated (45 mW/cm2) transepithelial corneal cross-linking for progressive keratoconus patients: long-term topographical and clinical outcomes. Front Med (Lausanne) 2020;7:283. DOI: 10.3389/fmed.2020.00283.
Marafon SB, Kwitko S, Marinho DR. Long-term results of accelerated and conventional corneal cross-linking. Int Ophthalmol 2020;40(10):2751–2761. DOI: 10.1007/s10792-020-01462-w.
Nicula CA, Nicula D, Rednik AM, et al. Comparative results of “Epi-Off” conventional versus “Epi-Off” accelerated cross-linking procedure at 5-year follow-up. J Ophthalmol 2020;2020:4745101. DOI: 10.1155/2020/4745101.
Ting DSJ, Rana-Rahman R, Chen Y, et al. Effectiveness and safety of accelerated (9 mW/cm2) corneal collagen cross-linking for progressive keratoconus: a 24-month follow-up. Eye (Lond) 2019;33(2):812–818. DOI: 10.1038/s41433-018-0323-9.
Vounotrypidis E, Athanasiou A, Kortüm K, et al. Long-term database analysis of conventional and accelerated crosslinked keratoconic mid-European eyes. Graefes Arch Clin Exp Ophthalmol 2018;256(6): 1165–1172. DOI: 10.1007/s00417-018-3955-3.
Cifariello F, Minicucci M, Di Renzo F, et al. Epi-Off versus Epi-On corneal collagen cross-linking in keratoconus patients: a comparative study through 2-year follow-up. J Ophthalmol 2018;2018:4947983. DOI: 10.1155/2018/4947983.
Ağca A, Tülü B, Yaşa D, et al. Accelerated corneal crosslinking in children with keratoconus: 5-year results and comparison of 2 protocols. J Cataract Refract Surg 2020;46(4):517–523. DOI: 10.1097/j.jcrs.0000000000000101.
Kirgiz A, Eliacik M, Yildirim Y. Different accelerated corneal collagen cross-linking treatment modalities in progressive keratoconus. Eye Vis (Lond) 2019;6:16. DOI: 10.1186/s40662-019-0141-6.
Amer I, Elaskary A, Mostafa A, et al. Long-term visual, refractive and topographic outcomes of “Epi-off” corneal collagen cross-linking in pediatric keratoconus: standard versus accelerated protocol. Clin Ophthalmol 2020;14:3747–3754. DOI: 10.2147/OPTH.S275797.
Beloshevski B, Shashar S, Mimouni M, et al. Comparison between three protocols of corneal collagen crosslinking in adults with progressive keratoconus: standard versus accelerated CXL for keratoconus. Eur J Ophthalmol 2020;1120672120972632. DOI: 10.1177/1120672120972632.
Turhan SA, Yargi B, Toker E. Efficacy of conventional versus accelerated corneal cross-linking in pediatric keratoconus: two-year outcomes. J Refract Surg 2020;36(4):265–269. DOI: 10.3928/1081597X-20200302-01.
Artola A, Piñero DP, Ruiz-Fortes P, et al. Clinical outcomes at one year following keratoconus treatment with accelerated transepithelial cross-linking. Int J Ophthalmol 2017;10(4):652–655. DOI: 10.18240/ijo.2017.04.24.
Piñero DP, Artola A, Ruiz-Fortes P, et al. Clinical outcomes at 1 year following corneal ectasia treatment with accelerated transepithelial cross-linking. Int J Kerat Ect Cor Dis 2016;5(3):93–98. DOI: 10.5005/jp-journals-10025-1128.
Yam JCS, Cheng ACK. Prognostic factors for visual outcomes after crosslinking for keratoconus and post-LASIK ectasia. Eur J Ophthalmol 2013;23(6):799–806. DOI: 10.5301/ejo.5000321.
Sahebjada S, Al-Mahrouqi HH, Moshegov S, et al. Eye rubbing in the aetiology of keratoconus: a systematic review and meta-analysis. Graefes Arch Clin Exp Ophthalmol 2021;259(8):2057–2067. DOI: 10.1007/s00417-021-05081-8.