0
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Early findings in a randomised controlled trial on crosslinking protocols using isoosmolar and hypoosmolar riboflavin for the treatment of progressive keratoconus

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Purpose

          To present baseline characteristics and to present the perioperative corneal thickness during corneal crosslinking (CXL) treatment for progressive keratoconus and to describe how the addition of sterile water (SW) efficaciously can maintain the corneal thickness. The treatment efficacy will be evaluated when the 1‐year follow‐up is complete.

          Methods

          A randomised clinical study using epithelium‐off CXL with continuous UVA irradiation (9 mW/cm 2) and two kinds of riboflavin solutions: (i) isoosmolar dextran‐based riboflavin ( n = 27) and (ii) hypoosmolar dextran‐free riboflavin ( n = 27). Inclusion criteria: progressive keratoconus with an increase in maximum keratometry value (Kmax) of 1.0 dioptre (12 months) or 0.5 dioptres (6 months). Corneae thinner than 400 μm were also included. Outcome parameters: Perioperative corneal thickness and the effect of adding SW.

          Results

          Seventy‐four per cent of the patients in the isoosmolar group and 15% in the hypoosmolar group required the addition of SW, which effectively maintained a corneal thickness of 400 μm in all cases during CXL. The addition of SW was primarily needed during the irradiation procedure and not the preoperative soaking period.

          Conclusions

          Especially during the CXL irradiation phase, isoosmolar riboflavin causes a significant dehydrating effect leading to corneal thinning during CXL. The customised addition of SW is efficacious in maintaining the corneal thickness during CXL and could increase the safety of the procedure.

          Related collections

          Most cited references41

          • Record: found
          • Abstract: not found
          • Article: not found

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

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Safety of UVA-riboflavin cross-linking of the cornea.

            To study potential damage to ocular tissue during corneal collagen cross-linking (X-linking) by means of the riboflavin/UVA (370 nm) approach. Comparison of the currently used technique with officially accepted guidelines regarding direct UV damage and the damage created by the induced free radicals (photochemical damage). The currently used UVA radiant exposure of 5.4 mJ/cm and the corresponding irradiance of 3 mW/cm2 is below the known damage thresholds of UVA for the corneal endothelium, lens, and retina. Regarding the photochemical damage caused by the free radicals, the damage thresholds for keratocytes and endothelial cells are 0.45 and 0.35 mW/cm, respectively. In a 400-microm-thick cornea saturated with riboflavin, the irradiance at the endothelial level was 0.18 mW/cm, which is a factor of 2 smaller than the damage threshold. After corneal X-linking, the stroma is depopulated of keratocytes approximately 300 microm deep. Repopulation of this area takes up to 6 months. As long as the cornea treated has a minimum thickness of 400 microm (as recommended), the corneal endothelium will not experience damage, nor will deeper structures such as lens and retina. The light source should provide a homogenous irradiance, avoiding hot spots.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Biomechanical evidence of the distribution of cross-links in corneas treated with riboflavin and ultraviolet A light.

              To examine to which depth of the cornea the stiffening effect is biomechanically detectable. Department of Ophthalmology, University of Dresden, Dresden, Germany. Of 40 enucleated porcine eyes, 20 eyes were treated with the photosensitizer riboflavin (0.1%) and ultraviolet A (UVA) light (370 nm, 3 mW/cm2, 30 minutes); the other 20 eyes served as control. From each eye, 2 flaps of 200 microm thickness were cut with a microkeratome, and strips of 5 mm width and 7 mm length were prepared. Stress-strain behavior was measured with a material tester to characterize the stiffening effect. Five pairs of human donor eyes were tested in the same way. In porcine corneas, the stiffening effect was stronger in the anterior-treated flaps than in the posterior-treated flaps and the control flaps (P = .001). A 5% strain was achieved at a stress of 261.7 +/- 133.2 x 10(3) N/m2 in the anterior-treated flaps and 104.1 +/- 52.7 x 10(3) N/m2 in the anterior control flaps. The posterior-treated flaps (105.0 +/- 55.8 x 10(3) N/m2) and the posterior control flaps (103.7 +/- 61.8 x 10(3) N/m2) showed no difference (P = .95). A similar stiffening effect was observed in human eyes, but contrary to findings in porcine corneas, in human corneas the anterior control flaps were stiffer than the posterior control flaps (P = .027). Treatment of the cornea with riboflavin and UVA significantly stiffened the cornea only in the anterior 200 microm. This depth-dependent stiffening effect may be explained by the absorption behavior for UVA in the riboflavin-treated cornea. Sixty-five percent to 70% of UVA irradiation was absorbed within the anterior 200 microm and only 20% in the next 200 microm. Therefore, deeper structures and even the endothelium are not affected.
                Bookmark

                Author and article information

                Contributors
                ingemar.gustafsson@med.lu.se
                Journal
                Acta Ophthalmol
                Acta Ophthalmol
                10.1111/(ISSN)1755-3768
                AOS
                Acta Ophthalmologica
                John Wiley and Sons Inc. (Hoboken )
                1755-375X
                1755-3768
                05 July 2024
                February 2025
                : 103
                : 1 ( doiID: 10.1111/aos.v103.1 )
                : 23-32
                Affiliations
                [ 1 ] Department of Ophthalmology Skåne University Hospital Malmö Sweden
                [ 2 ] Department of Clinical Sciences Lund University Lund Sweden
                [ 3 ] Department of Clinical Sciences Lund University Malmö Sweden
                [ 4 ] Department of Ophthalmology Aarhus University Hospital Aarhus Denmark
                Author notes
                [*] [* ] Correspondence

                Ingemar Gustafsson, Department of Ophthalmology, Skåne University Hospital, Kioskgatan 1, SE‐221 85 Lund, Sweden.

                Email: ingemar.gustafsson@ 123456med.lu.se

                Author information
                https://orcid.org/0000-0001-7001-0202
                Article
                AOS16736 ACTA-24-02-0233.R4
                10.1111/aos.16736
                11704820
                38970233
                327b0a74-3f0c-4bf6-b661-8ca0cf7962d9
                © 2024 The Author(s). Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

                This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

                History
                : 27 February 2024
                : 22 June 2024
                Page count
                Figures: 2, Tables: 4, Pages: 10, Words: 6700
                Categories
                Original Article
                Original Article
                Custom metadata
                2.0
                February 2025
                Converter:WILEY_ML3GV2_TO_JATSPMC version:6.5.2 mode:remove_FC converted:07.01.2025

                Ophthalmology & Optometry
                corneal crosslinking,keratoconus,progressive keratoconus,riboflavin
                Ophthalmology & Optometry
                corneal crosslinking, keratoconus, progressive keratoconus, riboflavin

                Comments

                Comment on this article

                scite_
                0
                0
                0
                0
                Smart Citations
                0
                0
                0
                0
                Citing PublicationsSupportingMentioningContrasting
                View Citations

                See how this article has been cited at scite.ai

                scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.

                Similar content739

                Most referenced authors297