Details
| Original language | English |
|---|---|
| Pages (from-to) | 6740-6746 |
| Number of pages | 7 |
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 56 |
| Issue number | 11 |
| Publication status | Published - Oct 2015 |
Abstract
PURPOSE. To determine the riboflavin concentration gradient in the anterior corneal stroma when using the Dresden protocol with different dextran solutions. METHODS. Three different groups of porcine corneas, five each, were compared regarding the riboflavin concentration in the anterior stroma. Before all experiments, stable hydration conditions were established for the corresponding solution. All groups were treated with 0.1% riboflavin in different dextran solutions (15%, 16%, 20%). After imbibition, two-photon microscopy was used to determine fluorescence intensity. For signal attenuation and concentration determination corneas were saturated and measured a second time by twophoton microscopy. Additionally, the distribution was calculated mathematically and compared to the empiric results. RESULTS. Riboflavin concentration is decreasing with depth for all dextran solutions. A nearly constant concentration could be determined over the first 75 lm. Analysis of the fit functions leads to diffusion coefficients of D = 2.97 × 10-7 cm2/s for the 15% dextran solution, D = 2.34 × 10-7 cm2/s for the 16% dextran solution, and D = 1.28 × 10-7 cm2/s for the 20% dextran solution. The riboflavin gradients of the 20% dextran group were statistically significantly different from 15% dextran starting at a depth of 220 mm and deeper (P = 0.047). The 16% dextran group differed statistically at a depth of 250 µm and deeper (P = 0.047). These results show a significant difference to those published previously. CONCLUSIONS. With correct settings two-photon microscopy is a precise way to determine the concentration of riboflavin in cornea. The measured gradient is excellently fit by a Gaussian distribution, which comes out as a solution of Fick’s second law.
Keywords
- Concentration, Cornea, Cross-linking, Riboflavin distribution, Two-photon microscopy
ASJC Scopus subject areas
- Medicine(all)
- Ophthalmology
- Neuroscience(all)
- Sensory Systems
- Neuroscience(all)
- Cellular and Molecular Neuroscience
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In: Investigative Ophthalmology and Visual Science, Vol. 56, No. 11, 10.2015, p. 6740-6746.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Two-photon fluorescence microscopy for determination of the riboflavin concentration in the anterior corneal stroma when using the dresden protocol
AU - Seiler, Theo
AU - Ehmke, Tobias
AU - Fischinger, Isaak
AU - Zapp, Daniel
AU - Stachs, Oliver
AU - Seiler, Theo
AU - Heisterkamp, Alexander
PY - 2015/10
Y1 - 2015/10
N2 - PURPOSE. To determine the riboflavin concentration gradient in the anterior corneal stroma when using the Dresden protocol with different dextran solutions. METHODS. Three different groups of porcine corneas, five each, were compared regarding the riboflavin concentration in the anterior stroma. Before all experiments, stable hydration conditions were established for the corresponding solution. All groups were treated with 0.1% riboflavin in different dextran solutions (15%, 16%, 20%). After imbibition, two-photon microscopy was used to determine fluorescence intensity. For signal attenuation and concentration determination corneas were saturated and measured a second time by twophoton microscopy. Additionally, the distribution was calculated mathematically and compared to the empiric results. RESULTS. Riboflavin concentration is decreasing with depth for all dextran solutions. A nearly constant concentration could be determined over the first 75 lm. Analysis of the fit functions leads to diffusion coefficients of D = 2.97 × 10-7 cm2/s for the 15% dextran solution, D = 2.34 × 10-7 cm2/s for the 16% dextran solution, and D = 1.28 × 10-7 cm2/s for the 20% dextran solution. The riboflavin gradients of the 20% dextran group were statistically significantly different from 15% dextran starting at a depth of 220 mm and deeper (P = 0.047). The 16% dextran group differed statistically at a depth of 250 µm and deeper (P = 0.047). These results show a significant difference to those published previously. CONCLUSIONS. With correct settings two-photon microscopy is a precise way to determine the concentration of riboflavin in cornea. The measured gradient is excellently fit by a Gaussian distribution, which comes out as a solution of Fick’s second law.
AB - PURPOSE. To determine the riboflavin concentration gradient in the anterior corneal stroma when using the Dresden protocol with different dextran solutions. METHODS. Three different groups of porcine corneas, five each, were compared regarding the riboflavin concentration in the anterior stroma. Before all experiments, stable hydration conditions were established for the corresponding solution. All groups were treated with 0.1% riboflavin in different dextran solutions (15%, 16%, 20%). After imbibition, two-photon microscopy was used to determine fluorescence intensity. For signal attenuation and concentration determination corneas were saturated and measured a second time by twophoton microscopy. Additionally, the distribution was calculated mathematically and compared to the empiric results. RESULTS. Riboflavin concentration is decreasing with depth for all dextran solutions. A nearly constant concentration could be determined over the first 75 lm. Analysis of the fit functions leads to diffusion coefficients of D = 2.97 × 10-7 cm2/s for the 15% dextran solution, D = 2.34 × 10-7 cm2/s for the 16% dextran solution, and D = 1.28 × 10-7 cm2/s for the 20% dextran solution. The riboflavin gradients of the 20% dextran group were statistically significantly different from 15% dextran starting at a depth of 220 mm and deeper (P = 0.047). The 16% dextran group differed statistically at a depth of 250 µm and deeper (P = 0.047). These results show a significant difference to those published previously. CONCLUSIONS. With correct settings two-photon microscopy is a precise way to determine the concentration of riboflavin in cornea. The measured gradient is excellently fit by a Gaussian distribution, which comes out as a solution of Fick’s second law.
KW - Concentration
KW - Cornea
KW - Cross-linking
KW - Riboflavin distribution
KW - Two-photon microscopy
UR - http://www.scopus.com/inward/record.url?scp=84944734416&partnerID=8YFLogxK
U2 - 10.1167/iovs.15-17656
DO - 10.1167/iovs.15-17656
M3 - Article
C2 - 26567785
AN - SCOPUS:84944734416
VL - 56
SP - 6740
EP - 6746
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 11
ER -