International Journal of Keratoconus and Ectatic Corneal Diseases

Register      Login

VOLUME 1 , ISSUE 2 ( May-August, 2012 ) > List of Articles


Biomechanical and Refractive Results of Transepithelial Cross-linking Treatment in Keratoconic Eyes

Cynthia J Roberts

Citation Information : Roberts CJ. Biomechanical and Refractive Results of Transepithelial Cross-linking Treatment in Keratoconic Eyes. Int J Kerat Ect Cor Dis 2012; 1 (2):75-78.

DOI: 10.5005/jp-journals-10025-1015

Published Online: 01-04-2014

Copyright Statement:  Copyright © 2012; The Author(s).



To analyze change in visual acuity (VA), refractive outcomes, corneal compensated intraocular pressure (IOPcc), corneal hysteresis (CH) and cornea resistance factor (CRF) after transepithelial cross-linking (CXL) treatment.


Kudret Eye Hospital, Ankara, Turkey

Materials and methods

A total of 32 eyes of 22 patients diagnosed with keratoconus were included in this retrospective study. Changes in VA, spheric and cylinderic refraction for all eyes were analyzed before and 3 months after transepithelial CXL. In addition, a subset of 14 eyes had data acquired using the ocular response analyzer (ORA), and for these eyes, IOPcc, CH and CRF were recorded as well as a measurement of the amplitude of the first peak in the infrared signal (peak 1), used to identify the inward applanation event. The ORA parameters were also compared before and 3 months after treatment.


Uncorrected and best corrected VA increased 1.76 and 1.61 Snellen lines (p < 0.05); spheric and cylinderic refractions improved 0.74 and 0.43 D (p > 0.05) respectively. Mean changes in IOPcc, CRF and CH were not significantly different (p > 0.05). However, mean peak 1 signal value increased significantly (p < 0.05).


Transepithelial CXL is effective in VA improvement in the short-term with an increase in the peak 1 signal value which is consistent with an increase in stiffness of cornea, whereas IOPcc, CRF and CH values remained the same.

How to cite this article

Klllç A, Roberts CJ. Biomechanical and Refractive Results of Transepithelial Cross-linking Treatment in Keratoconic Eyes. Int J Kerat Ect Cor Dis 2012;1(2):75-78.

PDF Share
  1. Mechanics of the cornea. In: Cavanagh HD (Ed), The cornea: Transactions of the world congress on the cornea III. New York, NY, Raven 1988;187-93.
  2. Induction of crosslinks in corneal tissue. Exp Eye Res 1998;66:97-103.
  3. Stress-strain measurements of human and porcine cornea after riboflavin/UVA-induced cross-linking. J Cataract Refract Surg 2003;29:1780-85.
  4. Prognostic factors to the progression of keratoconus. Ophthalmology 1994;101:439-47.
  5. A 48-year clinical and epidemiologic study of keratoconus. Am J Ophthalmol 1986;101:267-73.
  6. Riboflavin/ultraviolet-A- induced collagen cross-linking for the treatment of keratoconus. Am J Ophthalmol 2003;135:620-27.
  7. Effect of inferior-segment Intacs with and without C3-R on keratoconus. J Cataract Refract Surg 2007;33:75-80.
  8. Ageing of the human corneal stroma: Structural and biochemical changes. Biochim Biophys Acta 1992;1138:222-28.
  9. Mechanism of maturation and ageing of collagen. Mech Ageing Dev 1998;106:1-56.
  10. Advanced Maillard reaction and cross-linking of corneal collagen in diabetes. Biochem Biophys Res Com 1995;214:793-97.
  11. Induction of cross-links in corneal tissue. Exp Eye Res 1998;66:97-103.
  12. Determining in vivo biomechanical properties of the cornea with an ocular response analyzer. J Cataract Refract Surg 2005;31:156-62.
  13. Biomechanical evidence of the distribution of cross-links in corneas treated with riboflavin and ultraviolet A light. J Cataract Refract Surg 2006 Feb;32(2):279-83.
  14. Intra- and postoperative variation in ocular response analyzer parameters in keratoconic eyes after corneal cross-linking. J Refract Surg 2010 Apr;28:1-8.
  15. Biomechanical characteristics of the ectatic cornea. J Cataract Refract Surg 2008; 34(3):510-13.
  16. Comparison of biomechanical and topographic parameters in normal and pathologic corneas. ARVO 2007;E-Abstract 48:1843.
  17. A viscoelastic biomechanical model of the cornea describing the effect of viscosity and elasticity on hysteresis. Invest Ophthalmol Vis Sci 2008;49(9):3919-26.
  18. Epithelial, stromal and total corneal thickness in keratoconus: Three-dimensional display with artemis very- high frequency digital ultrasound. Journal of Refractive Surgery 2010;26(4):259-71.
  19. Apoptosis in UV-exposed rabbit corneas. Cornea 2000;19(1):99-103.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.