Bestrahlung der Hornhaut mit UV-Licht und Riboflavingabe als neuer Behandlungsversuch bei einschmelzenden Hornhautprozessen, erste Ergebnisse bei vier Patienten123

Schnitzler, E.; Spörl, E.; Seiler, Theo

doi:10.1055/s-2000-10344

Cited by 102 publications

(31 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The antioxidant action of riboflavin is performed through the reduced activity of flavoenzyme and glutathione reductase [8]. An adequate amount of dietary riboflavin is required for optimal activity of GSSG (oxidized glutathione) reductase [9]. Therefore, riboflavin deficiency may cause rather specific changes in the conjunctiva and cornea.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Riboflavin Deficiency Induces Ocular Surface Damage

Takami

Gong

Amemiya³

2004

Ophthalmic Res

View full text Add to dashboard Cite

Purpose: To examine the conjunctiva and cornea of riboflavin-deficient rats with scanning (SEM) and transmission (TEM) electron microscopes. Materials and Methods: Three-week-old Wistar Kyoto rats were fed a riboflavin-deficient diet (0.05 mg riboflavin/100 g) for 3 months. As a recovery experiment, rats which had been on a riboflavin-deficient diet for 3 months were given water with 1 mg riboflavin/300 ml for 2 months. The conjunctiva and the cornea were examined with SEM and TEM. Results: The serum riboflavin level was significantly lower in the riboflavin-deficient group than in the controls. In rats on a riboflavin-deficient diet for 3 months, SEM showed decreased microvilli and microplicae in the superficial epithelium of the conjunctiva and a decrease in the number of goblet cells. The cornea showed many dark cells and a marked decrease of microvilli and microplicae. In the riboflavin-deficient rats, TEM of the conjunctiva showed a decrease of microvilli and microplicae in the most superficial epithelial cells, a decrease in the layers of the epithelium and a marked decrease in the number of goblet cells, while the cornea had decreased microvilli and microplicae in the superficial epithelium, dark wing cells, loss of the basement membrane and hemidesmosomes of basal cells, cell debris and degenerative stroma cells and deposits of dense bodies in the subepithelial layer of the stroma. In rats recovered from riboflavin deficiency, the conjunctiva and cornea showed no abnormalities. Discussion: Riboflavin plays a role in the development and maintenance of the surface structures of epithelial cells. Riboflavin may also be necessary for the development and maintenance of goblet cells. Conclusion: Riboflavin is essential for maintaining the structure and function of the ocular surface.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Flavins are light-sensitive and are rapidly degraded when exposed to light in near-ultraviolet and visible wavelengths. Some of the by-products of flavin photodegradation are toxic, but this toxicity could be used to treat corneal ulcer [9]. The effect of riboflavin deficiency on the cornea was studied about 70 years ago.…”

Section: Introductionmentioning

confidence: 99%

Riboflavin Deficiency Induces Ocular Surface Damage

Takami

Gong

Amemiya³

2004

Ophthalmic Res

View full text Add to dashboard Cite

show abstract

“…An increased resistance to collagenases could be demonstrated. 5 Besides keratoconus and corneal ulcers, the new treatment can be used in corneal melting processes 6 and in the field of refractive surgery to reduce the risk for iatrogenic keratectasia after LASIK (laser assisted in situ keratomileusis). 7 The impact of various treatment modalities like corneal abrasion, PRK (photorefractive keratectomacy), 8 LASIK, 8,9 and epithelial injury [10][11][12] on keratocytes has gained considerable interest in recent years having a possible influence on scarring or corneal thinning.…”

Section: Introductionmentioning

confidence: 99%

Keratocyte cytotoxicity of riboflavin/UVA-treatment in vitro

Wollensak

Spoerl

Reber

et al. 2004

Eye

240

183

View full text Add to dashboard Cite

Purpose Collagen crosslinking using ultraviolet-A (UVA) -irradiation combined with the photosensitizer riboflavin is a new technique for treating progressive keratoconus. It has been shown to increase effectively the biomechanical strength of the cornea and to stop or even reverse the progression of keratoconus. As part of a safety evaluation, the present study was undertaken to investigate in vitro the possible cytotoxic effect of combined riboflavin/UVA-treatment on corneal keratocytes and to compare it to UVA-irradiation alone. Methods Cell cultures established from porcine keratocytes were treated with 0.025% riboflavin solution and various UVA (370 nm)-irradiances ranging from 0.4 to 1.0 mW/cm 2 and with UVA alone between 2 and 9 mW/cm 2 for 30 min. The cell cultures were evaluated for cell death 24 h after irradiation using trypanblue and Yopro-fluorescence staining. Results An abrupt cytotoxic irradiance level was found at 0.5 mW/cm 2 for keratocytes after UVA-irradiation combined with the photosensitizer riboflavin, which is 10-fold lower than the cytotoxic irradiance of 5 mW/ cm 2 after UVA-irradiation alone. Conclusions A cytotoxic effect of combined riboflavin/UVA-treatment on keratocytes is to be expected at 0.5 mW/cm 2 , which is reached in the clinical setting in human corneas down to a depth of 300 mm using the standard surface UVA-irradiance of 3 mW/cm 2 .

show abstract

“…In a prospective clinical pilot study including 22 patients with moderate or advanced progressive keratoconus followed up for up to 4 years, the progression of keratoconus could be stopped in all treated eyes; in 70% of the patients, even regression was achieved, with a reduction in the maximal keratometry readings by 2 diopters [5]. In addition, the method can be applied in corneal melting processes [6] and in corneal refractive laser surgery to prevent iatrogenic keratectasia [7].…”

Section: Introductionmentioning

confidence: 99%

Corneal Endothelial Cytotoxicity of Riboflavin/UVA Treatment in vitro

et al. 2003

Self Cite

View full text Add to dashboard Cite

Recently, we have developed collagen crosslinking induced by combined riboflavin/UVA treatment, thus increasing the biomechanical rigidity of the cornea to treat progressive keratoconus. The present safety study was performed to evaluate possible cytotoxic effects of combined riboflavin/UVA treatment on the corneal endothelium in vitro. Endothelial cell cultures from porcine corneas were treated with 500 µM riboflavin solution, exposed to various endothelial UVA irradiances (370 nm) ranging from 0.1 to 1.6 mW/cm² for 30 min and evaluated 24 h later using trypan blue staining and Yopro fluorescence staining. The effect of either treatment alone (UVA irradiation ranging from 0.2 to 6 mW/cm²) was also tested. An abrupt cytotoxic threshold irradiance level was found at 0.35 mW/cm² after combined treatment with riboflavin plus UVA irradiation and at 4 mW/cm² with UVA irradiation alone. Riboflavin alone was not toxic. A cytotoxic effect of the combined riboflavin/UVA treatment on corneal endothelial cells is to be expected with a corneal thickness of less than 400 µm. Therefore, pachymetry should be routinely performed before riboflavin/UVA treatment to exclude patients at risk.

show abstract

Bestrahlung der Hornhaut mit UV-Licht und Riboflavingabe als neuer Behandlungsversuch bei einschmelzenden Hornhautprozessen, erste Ergebnisse bei vier Patienten123

Abstract: Because of the absence of any side-effects in serious cases the method is recommended prior to surgery.

Cited by 102 publications

References 9 publications

Riboflavin Deficiency Induces Ocular Surface Damage

Riboflavin Deficiency Induces Ocular Surface Damage

Keratocyte cytotoxicity of riboflavin/UVA-treatment in vitro

Corneal Endothelial Cytotoxicity of Riboflavin/UVA Treatment in vitro

Contact Info

Product

Resources

About