Original Articles
Riboflavin/ultraviolet-a–induced collagen crosslinking for the treatment of keratoconus

https://doi.org/10.1016/S0002-9394(02)02220-1Get rights and content

Abstract

Purpose

In animal eyes, a significant increase in corneal biomechanical stiffness has been found after collagen crosslinking by combined riboflavin/ultraviolet-A (UVA) treatment. The aim of the present study was to evaluate the clinical usefulness of riboflavin/UVA-induced collagen crosslinking for bringing the progression of keratoconus to a halt.

Design

Prospective, nonrandomized clinical pilot study.

Methods

Twenty-three eyes of 22 patients with moderate or advanced progressive keratoconus (maximum K value, 48–72 diopters) were included. After central corneal abrasion, photosensitizing riboflavin drops were applied and the eyes exposed to UVA (370 nm, 3 mW/cm2) in a 1-cm distance for 30 minutes. Postoperative examinations were performed in 6-month intervals, including visual acuity testing, corneal topography, slit-lamp examination, measurement of endothelial cell density, and photographic documentation. The follow-up time was between 3 months and 4 years.

Results

In all treated eyes, the progression of keratoconus was at least stopped. In 16 eyes (70%) regression with a reduction of the maximal keratometry readings by 2.01 diopters and of the refractive error by 1.14 diopters was found. Corneal and lens transparency, endothelial cell density, and intraocular pressure remained unchanged. Visual acuity improved slightly in 15 eyes (65%).

Conclusions

Collagen crosslinking may be a new way for stopping the progression of keratectasia in patients with keratoconus. The need for penetrating keratoplasty might then be significantly reduced in keratoconus. Given the simplicity and minimal costs of the treatment, it might also be well-suited for developing countries. Long-term results are necessary to evaluate the duration of the stiffening effect and to exclude long term side-effects.

Section snippets

Design

This was a prospective, non-randomized pilot study.

Setting and patients

Starting in 1998, 23 eyes of 22 patients (10 females, 12 males) from the University Eye Clinic of Dresden were included in the study. The clinical diagnosis of keratoconus was based on corneal topography (Figure 3) and clinical signs of keratoconus such as stromal thinning, Fleischer ring, Vogt striae, or apical stromal scar. The preoperative progression of keratoconus was confirmed from medical history in all patients, and it was clearly documented by serial corneal topography12 in 12 eyes

Results

The follow-up time ranged from 3 to 47 months, with a mean follow-up time of 23.2 ± 12.9 months (TABLE 1, TABLE 2). Best-corrected visual acuity improved statistically significantly in 15 patients (65%) by an average of 1.26 lines (95% confidence interval, −0.68 to 2.21; P = .026, paired Student t test), comparing the preoperative values on the day of treatment vs the postoperative values of the last examination. The refractive correction improved significantly by an average of 1.14 diopters

Discussion

This study has shown that collagen-crosslinking appears to be effective in stopping the progression of keratoconus quasi “freezing” the cornea. This effect is corroborated by the following data of the study1: Postoperative regression was observed in 70% of patients with a decrease of the mean keratometer values by 2.01 diopters postoperatively despite documented preoperative progression by 1.42 diopters in 52%.2 The postoperative refractive corrections could also be reduced by an average of

Acknowledgements

The authors thank Prof. Josef Wollensak (Berlin) for continuous support and stimulation in the development of the new method.

References (35)

  • A.J. Bailey et al.

    Mechanisms of maturation and ageing of collagen

    Mech Ageing Dev

    (1998)
  • J.G. Jose et al.

    Wavelength dependency of cataracts in albino mice following chronic exposure

    Exp Eye Res

    (1985)
  • C. Argento et al.

    Corneal ectasia after laser in situ keratomileusis

    J Cataract Refract Surg

    (2001)
  • W. Sekundo et al.

    Surgical treatment of keratoconus at the turn of the 20th century

    J Refract Surg

    (2001)
  • M.J. Jaeger et al.

    Epikeratoplasty for keratoconus. A clinicopathologic case report

    Cornea

    (1987)
  • H.J. Hettlich et al.

    Light induced endocapsular polymerization of injectable lens refilling materials

    Ger J Ophthalmol

    (1992)
  • E. Spoerl et al.

    Untersuchungen zur Verfestigung der Hornhaut am Kaninchen

    Ophthalmologe

    (2000)
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