Kobashi Hidenaga, Yano Takashi, Tsubota Kazuo
Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
Tsubota Laboratory Inc., Tokyo, Japan.
Front Med (Lausanne). 2023 May 24;10:1109689. doi: 10.3389/fmed.2023.1109689. eCollection 2023.
We 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.
After 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/cm) 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.
A 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.
VL irradiation did not cause regression of corneal steepening in a collagenase-induced model during short-term observation.
我们评估了胶原酶治疗在建立兔圆锥角膜模型中的应用，以及紫光（VL）照射对6只日本白兔该疾病模型的影响。
上皮清创后，胶原酶组用II型胶原酶溶液处理30分钟；对照组用不含胶原酶的溶液处理。3只兔子在局部应用胶原酶后，还接受了VL照射（375nm，辐照度310μW/cm），每天照射3小时，共7天。在手术前后检查裂隙灯显微镜检查结果、陡峭角膜曲率（Ks）、角膜散光、中央角膜厚度和眼轴长度。在第7天获取角膜进行生物力学评估。
与对照组相比，胶原酶组和VL照射组在第7天观察到Ks和角膜散光显著增加。各组之间角膜厚度变化无显著差异。胶原酶组在3%、5%和10%应变下的弹性模量显著低于对照组。胶原酶组和VL照射组在任何应变水平下的弹性模量均无显著差异。胶原酶组和VL照射组在第7天的平均眼轴长度显著长于对照组。胶原酶治疗通过增加角膜曲率和散光值诱导了圆锥角膜模型。在生理相关应力水平下，正常角膜和扩张角膜的弹性行为观察无显著差异。
在短期观察中，VL照射未导致胶原酶诱导模型中角膜陡峭程度的消退。
