Evaluation of the Physiological Corneal Intrastromal Riboflavin Concentration and the Corneal Elastic Modulus After Violet Light Irradiation

Kobashi, Hidenaga; Yunoki, Shunji; Kato, Naoko; Shimazaki, Jun; Ide, Takeshi; Tsubota, Kazuo

doi:10.1167/tvst.10.5.12

Cited by 3 publications

(6 citation statements)

References 29 publications

(30 reference statements)

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“…Further research is needed to measure the concentration of riboflavin in rabbit corneas in vivo . In our previous study without collagenase treatment, the KeraVio without riboflavin (VL irradiation only) and standard CXL groups showed a significantly higher elastic modulus than the control group consisting of normal eyes, whereas no significant difference between the KeraVio and CXL groups was found ( 12 ). The preliminary data indicated similar outcomes between the two treatment groups ( 12 ).…”

Section: Discussionmentioning

confidence: 91%

“…In our previous study without collagenase treatment, the KeraVio without riboflavin (VL irradiation only) and standard CXL groups showed a significantly higher elastic modulus than the control group consisting of normal eyes, whereas no significant difference between the KeraVio and CXL groups was found ( 12 ). The preliminary data indicated similar outcomes between the two treatment groups ( 12 ). To the best of our knowledge, this is the first study to investigate corneal biometry and biomechanics after treatment with collagenase and with and without KeraVio.…”

Section: Discussionmentioning

confidence: 91%

“…Because the current study did not include corneal changes after the CXL technique, it was difficult to determine whether KeraVio outperformed CXL in terms of preventing corneal changes. We previously compared the elastic modulus after KeraVio and standard CXL treatments without collagenase application using porcine corneas ( 12 ). The model of the previous ex vivo study ( 12 ) differed in terms of species from the rabbit model in this study.…”

Section: Discussionmentioning

confidence: 99%

“…We previously compared the elastic modulus after KeraVio and standard CXL treatments without collagenase application using porcine corneas ( 12 ). The model of the previous ex vivo study ( 12 ) differed in terms of species from the rabbit model in this study. Further research is needed to measure the concentration of riboflavin in rabbit corneas in vivo .…”

Section: Discussionmentioning

confidence: 99%

“…KeraVio treatment avoids these complications of CXL surgery and may become another option for KC treatment, but its efficacy has not been compared with that of CXL. To simplify the treatment procedure, we preliminarily identified originally endogenous riboflavin in the human cornea without adding riboflavin drops, and a relatively low intensity of VL irradiation itself strengthened the corneal stiffness in porcine corneas ( 12 ). In a normal eye, VL is absorbed by the cornea, which contains physiological riboflavin and other photosensitizers, leading to CXL in the cornea.…”

Section: Introductionmentioning

confidence: 99%

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Combination of violet light irradiation and collagenase treatments in a rabbit model of keratoconus

Kobashi

Yano²,

Tsubota

2023

Front. Med.

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PurposeWe evaluated the use of collagenase treatment to generate a rabbit model of keratoconus and the impact of violet light (VL) irradiation on the disease model in six Japanese White rabbits.MethodsAfter epithelial debridement, the collagenase group was treated with a collagenase type II solution for 30 min; the control group was treated with a solution without collagenase. Three rabbits also underwent VL irradiation (375 nm, irradiance 310 μW/cm2) for 3 h daily for 7 days after topical collagenase application. Slit-lamp microscopy results, steep keratometry (Ks), corneal astigmatism, central corneal thickness, and axial length were examined before and after the procedure. The corneas were obtained on day 7 for biomechanical evaluation.ResultsA significant increase in Ks and corneal astigmatism was observed in the collagenase and VL irradiation groups compared with the control group on day 7. No significant difference was found in the change in corneal thickness between the groups. The elastic modulus at 3, 5, and 10% strain was significantly lower in the collagenase group than in the control group. There was no significant difference in the elastic modulus at any level of strain between the collagenase and VL irradiation groups. The average axial length at day 7 was significantly longer in the collagenase and VL irradiation groups than in the control group. Collagenase treatment induced a model of keratoconus by steepening the keratometric and astigmatic values. There was no significant difference in the observed elastic behavior of normal and ectatic corneas under physiologically relevant stress levels.ConclusionVL irradiation did not cause regression of corneal steepening in a collagenase-induced model during short-term observation.

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Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Combination of violet light irradiation and collagenase treatments in a rabbit model of keratoconus

Kobashi

Yano²,

Tsubota

2023

Front. Med.

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Properties of the acellular porcine cornea crosslinked with UVA/riboflavin as scaffolds for Boston Keratoprosthesis

Zhao

Wang³

et al. 2022

Biomaterials Advances

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Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China

Xiang,

Cheng,

Sun

et al. 2024

BMJ Open

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ObjectiveTo investigate the differences in myopia prevalence and ocular biometry in children and adolescents in Chongqing and Tibet, China.DesignCross-sectional study.SettingThe study included children and adolescents aged 6–18 years in Chongqing, a low-altitude region, and in Qamdo, a high-altitude region of Tibet.ParticipantsA total of 448 participants in Qamdo, Tibet, and 748 participants in Chongqing were enrolled in this study.MethodsAll participants underwent uncorrected visual acuity assessment, non-cycloplegic refraction, axial length (AL) measurement, intraocular pressure (IOP) measurement and corneal tomography. And the participants were grouped according to age (6–8, 9–11, 12–14 and 15–18 years group), and altitude of location (primary school students: group A (average altitude: 325 m), group B (average altitude: 2300 m), group C (average altitude: 3250 and 3170 m) and group D (average altitude: 3870 m)).ResultsThere was no statistical difference in mean age (12.09±3.15 vs 12.2±3.10, p=0.549) and sex distribution (males, 50.4% vs 47.6%, p=0.339) between the two groups. The Tibet group presented greater spherical equivalent (SE, −0.63 (−2.00, 0.13) vs −0.88 (−2.88, –0.13), p<0.001), shorter AL (23.45±1.02 vs 23.92±1.19, p<0.001), lower prevalence of myopia (39.7% vs 47.6%, p=0.008) and flatter mean curvature power of the cornea (Km, 43.06±1.4 vs 43.26±1.36, p=0.014) than the Chongqing group. Further analysis based on age subgroups revealed that the Tibet group had a lower prevalence of myopia and higher SE in the 12–14, and 15–18 years old groups, shorter AL in the 9–11, 12–14 and 15–18 years old groups, and lower AL to corneal radius of curvature ratio (AL/CR) in all age subgroups compared with the Chongqing group, while Km was similar between the two groups in each age subgroup. Simple linear regression analysis showed that SE decreased with age in both the Tibet and Chongqing groups, with the Tibet group exhibiting a slower rate of decrease (p<0.001). AL and AL/CR increased with age in both the Tibet and Chongqing groups, but the rate of increase was slower in the Tibet group (p<0.001 of both). Multiple linear regression analysis revealed that AL had the greatest effect on SE in both groups, followed by Km. In addition, the children and adolescents in Tibet presented thinner corneal thickness (CCT, p<0.001), smaller white to white distance (WTW, p<0.001), lower IOP (p<0.001) and deeper anterior chamber depth (ACD, p=0.015) than in Chongqing. Comparison of altitude subgroups showed that the prevalence of myopia (p=0.002), SE (p=0.031), AL (p=0.001) and AL/CR (p<0.001) of children at different altitudes was statistically different but the Km (p=0.189) were similar. The highest altitude, Tengchen County, exhibited the lowest prevalence of myopia and greatest SE among children, and the mean AL also decreased with increasing altitude.ConclusionsMyopia prevalence in Tibet was comparable with that in Chongqing for students aged 6–8 and 9–11 years but was lower and myopia progressed more slowly for students aged 12–14 and 15–18 years than in Chongqing, and AL was the main contributor for this difference, which may be related to higher ultraviolet radiation exposure and lower IOP in children and adolescents at high altitude in Tibet. Differences in AL and AL/CR between Tibet and Chongqing children and adolescents manifested earlier than in SE, underscoring the importance of AL measurement in myopia screening.

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Evaluation of the Physiological Corneal Intrastromal Riboflavin Concentration and the Corneal Elastic Modulus After Violet Light Irradiation

Cited by 3 publications

References 29 publications

Combination of violet light irradiation and collagenase treatments in a rabbit model of keratoconus

Combination of violet light irradiation and collagenase treatments in a rabbit model of keratoconus

Properties of the acellular porcine cornea crosslinked with UVA/riboflavin as scaffolds for Boston Keratoprosthesis

Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China

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