International Journal of Keratoconus and Ectatic Corneal Diseases

Register      Login

VOLUME 3 , ISSUE 3 ( September-December, 2014 ) > List of Articles

RESEARCH ARTICLE

The Effects of Epithelium-off Corneal Collagen Cross-linking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus

Adam Muzychuk, Victor Penner, Guillermo Rocha, Ahmed Al-Ghoul

Citation Information : Muzychuk A, Penner V, Rocha G, Al-Ghoul A. The Effects of Epithelium-off Corneal Collagen Cross-linking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus. Int J Kerat Ect Cor Dis 2014; 3 (3):113-117.

DOI: 10.5005/jp-journals-10025-1089

Published Online: 01-12-2014

Copyright Statement:  Copyright © 2014; Jaypee Brothers Medical Publishers (P) Ltd.


Abstract

Purpose

To utilize Scheimpflug imaging to describe corneal changes in keratoconic patients undergoing collagen cross- linking.

Study type

Case series.

Study design

Retrospective chart review at two sites: Calgary, Alberta and Brandon, Manitoba, Canada. All patients were diagnosed with keratoconus and had undergone corneal collagen crosslinking. All patients had pre- and post-procedure imaging done with Oculus Pentacam.

Results

Sixty-one eyes of 48 patients with 6 months follow- up and 36 eyes of 27 patients with one year follow-up were included. Average age was 27 ± 12 years (15-48 years). Fifty- one males and 10 females were studied. At 1 year follow-up, all Pentacam indices were found to improve: ISV −4.44 ± 18.6 (p = 0.16), IVA −0.07 ± 0.27 (p = 0.12), KI −0.009 ± 0.082 (p = 0.49), CKI −0.012 ± 0.027 (p = 0.01), IHA −3.87 ± 23.3 (p = 0.33) and IDH −0.062 ± 0.308 (p = 0.24). Keratometry measurements were flatter at the pupil centre by 0.87 ± 2.53 D (p = 0.05). Kmax and Kmin were flatter by 0.58 ± 1.37 D (p = 0.02) and 0.33 ± 1.70 D (p = 0.25) respectively. Pupil center pachymetry was thinner by 12.9 ± 21.1 µm (p = 0.0006) at 6 months, as were the corneal apex and thinnest local by 12.9 ± 22.3 µm (p = 0.001) and 21.8 ± 54.6 µm (p = 0.05) respectively. However, all central pachymetry readings were not statistically different from baseline at the one year measurements. Peripheral corneal measurements at 6 mm diameter were no different from baseline at 6 months, however, were significantly thicker at the 1 year follow-up.

Conclusion

The data, in this study, points to a more uniform cornea post corneal collagen crosslinking. The inferior cornea becomes flatter and superior cornea steeper with less variation when comparing the corneal curvatures. The peripheral cornea becomes thicker at 1 year post-procedure. Collagen cross- linking stabilizes the cornea.

How to cite this article

Penner V, Muzychuk A, Al-Ghoul A, Rocha G. The Effects of Epithelium-off Corneal Collagen Crosslinking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus. Int J Kerat Ect Cor Dis 2014;3(3):113-117.


PDF Share
  1. Transepithelial Riboflavin/Ultraviolet A Corneal Crosslinking in Keratoconus: Morphologic Studies on Human Corneas. Am J Ophthalmol 2013 Nov;156(5):874-884.
  2. Non-destructive mechanical characterisation of UVA/riboflavin crosslinked collagen hydrogels. Br J Ophthalmol 2008;92(2):268-271.
  3. Stress-strain measurements of human and porcine corneas after riboflavin-ultraviolet- A-induced crosslinking. J Cataract Refract Surg 2003;29(9): 1780-1785.
  4. Crosslinking treatment of progressive keratoconus: new hope. Current Opinion in Ophthalmology 2006;17(4):356-360.
  5. , Balasubramanian D. A study of the photodynamic efficiencies of some eye lens constituents. Photochemistry and Photobiology 1991;54(1): 51-58.
  6. Comparison of central corneal thickness measurements by rotating Scheimpflug camera, ultrasonic pachymetry, and scanning-slit corneal topography. Ophthalmology 2006;113(6):937-941.
  7. Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low-coherence reflectometry pachymeter, and ultrasound pachymetry. J Cataract Refract Surg 2005;31(9):1729-1735.
  8. Central corneal thickness measurements in unoperated eyes and eyes after PRK for myopia using Pentacam, Orbscan II, and ultrasonic pachymetry. J Refract Surg 2007;23(9):888-894.
  9. Corneal thickness measurements in normal and keratoconic eyes: Pentacam comprehensive eye scanner versus noncontact specular microscopy and ultrasound pachymetry. J Cataract Refract Surg 2006;32(6):970-977.
  10. Reproducibility and repeatability of central corneal thickness measurement in keratoconus using the rotating Scheimpflug camera and ultrasound pachymetry. Am J Ophthalmol 2007;144(5):712-718.
  11. Riboflavin/ultraviolet-a- induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135(5):620-627.
  12. 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(4):585-593.
  13. Parasurgical therapy for keratoconus by riboflavin-ultraviolet type A rays induced crosslinking of corneal collagen: preliminary refractive results in an Italian study. J Cataract Refract Surg 2006;32(5):837-845.
  14. Collagen crosslinking with riboflavin and ultraviolet—A light in keratoconus: long-term results. J Cataract Refract Surg 2008; 34(5):796-801.
  15. Refractive, topographic, tomographic, and aberrometric analysis of keratoconic eyes undergoing corneal crosslinking. Ophthalmology 2009; 116(3):369-378.
  16. Corneal collagen cross-linking for keratoconus and corneal ectasia: One-year results. J Cataract Refract Surg 2011;37(1):149-160.
  17. Prospective longitudinal study of corneal collagen crosslinking in progressive keratoconus. Clini Experimental Ophthalmol 2013;41(6):531-536.
  18. Scheimpflug imaging of corneas after collagen crosslinking. Cornea 2009;28(5):510-515.
  19. Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. J Cataract Refract Surg 2011;37(7):1282-1290.
  20. Pentacam Indices— A Sensitive Tool to Study the Effect of Corneal Collage Crosslinking on Keratoconus. All Indian Ophthalmological Society Meeting. Kolkata, India 2010.
  21. Corneal collagen crosslinking using riboflavin and ultraviolet—a light for keratoconus: one-year analysis using Scheimpflug imaging. J Cataract Refract Surg 2009;35(3):425-432.
  22. Contralateral eye study of corneal collagen crosslinking with riboflavin and UVA irradiation in patients with keratoconus. J Refract Surg 2009;25(4):371-376.
  23. Corneal collagen crosslinking with riboflavin and ultraviolet—a light for keratoconus: results in Indian eyes. Ind J Ophthalmol 2009;57(2):111-114.
  24. Intra- operative and postoperative effects of corneal collagen crosslinking on progressive keratoconus. Archives of Ophthalmology 2009;127(10):1258-1265.
  25. Riboflavin/Ultraviolet a corneal collagen crosslinking for the treatment of keratoconus: visual out-comes and Scheimpflug analysis. Cornea 2011;30(3):281-286.
  26. Corneal collagen cross-linking in progressive keratoconus: multicenter results from the French National Reference Center for Keratoconus. J Cataract Refract Surg 2011;37(12):2137-2143.
  27. Corneal collagen crosslinking: ectasia and beyond. Current Opinion in Ophthalmology 2012;23(4):280-287.
  28. Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. J Cataract Refract Surg 2011;37(4):691-700.
  29. Immunofluorescence confocal microscopy of porcine corneas following collagen crosslinking treatment with riboflavin and ultraviolet A. J Refract Surg 2008;24(7):S715-719.
  30. Corneal crosslinking-induced stromal demarcation line. Cornea 2006;25(9):1057-1059.
  31. Hydration behavior of porcine cornea crosslinked with riboflavin and ultraviolet A. J Cataract Refract Surg 2007;33(3):516-521.
  32. The swelling pressure of the corneal stroma. Investigative Ophthalmol 1962;1: 158-162.
  33. Wound healing in the rabbit cornea after corneal collagen crosslinking with riboflavin and UVA. Cornea 2007;26(5):600-605.
  34. Corneal healing after riboflavin ultraviolet-A collagen crosslinking determined by confocal laser scanning microscopy in vivo: early and late modifications. Am J Ophthalmol 2008;146(4):527-533.
  35. Keratocyte apoptosis after corneal collagen crosslinking using riboflavin/ UVA treatment. Cornea 2004;23(1):43-49.
  36. Confocal microscopy identification of keratoconus associated with posterior polymorphous corneal dystrophy. J Cataract Refract Surg 2008;34(2):318-321.
  37. Collagens and proteoglycans of the corneal extracellular matrix. Braz J Medi Biol Res 2003;36(8): 1037-1046.
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.