Hasan KIZILTOPRAK, Emre AYDEMİR, Gözde AKSOY AYDEMİR, Kemal ÖZÜLKEN, Erdem YÜKSEL

Comparison of Two Different Accelerated Corneal Cross-linking Procedure Outcomes in Patients with Keratoconus

Background: Corneal cross-linking treatment is the unique treatmentmethod that can cease the progression of keratoconus disease.Because of the long duration of conventional treatment, acceleratedcross-linking treatment methods are being developed.Aims: To compare two different accelerated corneal cross-linkingprotocols in terms of postoperative visual acuity and topographicfindings (higher-order aberrations and keratometry values).Study Design: Retrospective comparative study.Methods: Sixty-five eyes of 43 patients (30 men and 13 women)who underwent two different accelerated corneal cross-linkingprotocols (10 min, 9 mW/cm2 and 5 min, 18 mW/cm2) for progressivekeratoconus were retrospectively analyzed. Patients were dividedinto two groups according to the accelerated corneal cross-linkingtreatment protocol: group 1 (10 min, 9 mW/cm2, 32 eyes of 21patients) and group 2 (5 min, 18 mW/cm2, 33 eyes of 22 patients).Uncorrected visual acuity and best-corrected visual acuity values andtopographic findings (central corneal thickness and flat and steepkeratometry values) were recorded preoperatively and 6 monthsafter corneal cross-linking treatment. High-order aberration valuesmeasured with Pentacam preoperatively and 6 months after cornealcross-linking were also recorded.Results: In both groups, a significant improvement was detected inthe uncorrected visual acuity and best-corrected visual acuity levelspreoperatively and 6 months postoperatively (group 1: p=0.001,p=0.001 and group 2: p=0.001, p=0.001, respectively). In addition,central corneal thickness values decreased significantly in both groups(p=0.006 and 0.001). Trefoil values showed no significant differencepreoperatively and 6 months postoperatively in group 1 (p=0.160and 0.620, respectively). In groups 1 and 2, coma values were foundto decrease significantly in the 6th postoperative month comparedwith preoperative values (p=0.001 and 0.020, respectively). Therewas no significant difference between preoperative and 6th monthpostoperative horizontal and vertical trefoil values in both groups(p=0.850 and 0.140, respectively). There was no significant differencebetween the two groups in terms of preoperative and 6th monthpostoperative higher-order aberrations, refractive errors, keratometryvalues, and uncorrected visual acuity and best-corrected visual acuitylevels.Conclusion: Both accelerated corneal cross-linking proceduresprovide similar improvement in topographic findings, coma valuesand visual acuity

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1. Galvis V, Sherwin T, Tello A, Merayo J, Barrera R, Acera A. Keratoconus: an inflammatory disorder? Eye (Lond) 2015;29:843-59.
2. Or H. An Up-To-Date View at the Etiopathogenesis of Keratoconus. Turk J Ophthalmol 2011;41:339-47.
3. Spoerl E, Huhle M, Seiler T. Induction of cross-links in corneal tissue. Exp Eye Res 1998;66:97-103.
4. Parkin BT, Smith VA, Easty DL. The control of matrix metalloproteinase-2 expression in normal and keratoconic corneal keratocyte cultures. Eur J Ophthalmol 2000;10:276-85.
5. Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet- a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135:620-7.
6. Hafezi F, Mrochen M, Iseli HP, Seiler T. Collagen crosslinking with ultraviolet-A and hypoosmolar riboflavin solution in thin corneas. J Cataract Refract Surg 2009;35:621-4.
7. Hammer A, Richoz O, Arba Mosquera S, Tabibian D, Hoogewoud F, Hafezi F. Corneal biomechanical properties at different corneal cross-linking (CXL) irradiances. Invest Ophthalmol Vis Sci 201455:2881-4.
8. Maeda N, Fujikado T, Kuroda T, Mihashi T, Hirohara Y, Nishida K, et al. Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus. Ophthalmology 2002;109:1996-2003.
9. Polat N, Aydın EY, Tuncer I. Optic aberrations and wavefront. Turkish Journal Ophthalmology 2014;44:306-11.
10. Vinciguerra P, Albe E, Trazza S, Rosetta P, Vinciguerra R, Seiler T, et al. Refractive, topographic, tomographic, and aberrometric analysis of keratoconic eyes undergoing corneal cross-linking. Ophthalmology 2009;116:369–78.
11. Hersh PS, Greenstein SA, Fry KL. Corneal collagen crosslinking for keratoconus and corneal ectasia: one year results. J Cataract Refract Surg 2011;37:149–60.
12. Sherif AM. Accelerated versus conventional corneal collagen cross-linking in the treatment of mild keratoconus: a compara- tive study. Clin Ophthalmol 2014;8:1435-40.
13. Gautam, Jhanji V, Satpathy G, Khokhar S, Agarwal T. Microsporidial keratitis after collagen cross-linking. Ocul Immunol Inflamm 2013;21:495-7.
14. Brindley GS. The Bunsen-Roscoe law for the human eye at very short durations. J Physiol 1952;118:135–9.
15. Schumacher S, Oeftiger L, Mrochen M. Equivalence of biomechanical changes induced by rapid and standard corneal cross-linking, using riboflavin and ultraviolet radiation. Invest Ophthalmol Vis Sci 2011;52:9048–52.
16. Tomita M, Mita M, Huseynova T. Accelerated versus conventional corneal collagen crosslinking. J Cataract Refract Surg 2014;40:1013–20.
17. Wernli J, Schumacher S, Spoerl E, Mrochen M. The efficacy of corneal cross-linking shows a sudden decrease with very high intensity UV light and short treatment time. Invest Ophthalmol Vis Sci 2013;54:1176-80.
18. Huang R, Choe E, Min DB. Kinetics for singlet oxygen formation by riboflavin photosensitization and the reaction between riboflavin and singlet oxygen. J Food Sci 2004;69:C726-C32.
19. Vinciguerra P. The efficacy of corneal cross-linking shows a sudden decrease with very high intensity UV lightand short treatment time. Invest Ophthalmol Vis Sci 2013;54.
20. Kirgiz A, Eliacik M, Yildirim Y. Different accelerated corneal collagen cross-linking treatment modalities in progressive keratoconus. Eye Vis (Lond) 2019;6:16.
21. Choi M, Kim J, Kim EK, Seo KY, Kim TI. Comparison of the conventional Dresden protocol and accelerated protocol with higher ultraviolet intensity in corneal collagen cross-linking for keratoconus. Cornea 2017;36:523–9. 22. Hashemi H, Mohebbi M, Asgari S. Standard and accelerated corneal cross-linking longterm results: A randomized clinical trial. Eur J Ophthalmol 2019:1120672119839927.
23. Kato N, Konomi K, Shinzawa M, Kasai K, Ide T, Toda I, et al. Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures. Jpn J Ophthalmol 2018;62:560-7.
24. Yildirim Y, Olcucu O, Gunaydin ZK, Ağca A, Ozgurhan EB, Alagoz C, et al. Comparison of accelerated corneal collagen cross-linking types for treating keratoconus. Curr Eye Res 2017;42:971–5.
25. Schlegel Z, Lteif Y, Bains HS, Gatinel D. Total, corneal, and internal ocular optical aberrations in patients with keratoconus. J Refract Surg 2009;25(10 Suppl):S951–7.
26. Alió JL, Shabayek MH. Corneal higher order aberrations: a method to grade keratoconus. J Refract Surg 2006;22:539–45.
27. Greenstein SA, Fry KL, Hersh MJ, Hersh PS. Higher-order aberrations after corneal collagen crosslinking for keratoconus and corneal ectasia. J Cataract Refract Surg 2012;38:292-302
28. Kocamış Sİ, Çakmak HB, Uğurlu N, Çağıl N. Keratokonusta Çapraz Bağlama Tedavisinin Konus Kırıcılığı ve Yüksek Sıralı Korneal Aberasyonlar Üzerine Etkisi. Turk J Ophthalmol 2014;44:184-9.
29. Caporossi A, Mazzotta C, Baiocchi S, Caporossi T. Long-term results of riboflavin ultraviolet a corneal collagen cross-linking for keratoconus in Italy: the Siena eye cross study. Am J Ophthalmol 2010;149:585-93.
30. Baumeister M, Klaproth OK, Gehmlich J, Bühren J, Kohnen T. Changes in corneal first-surface wavefront aberration after corneal collagen cross-linking in keratoconus. Klin Monbl Augenheilkd 2009;226:752-6.